JP2005029991A - Method for reinforcing concrete structures - Google Patents

Abstract

The present invention provides a method for reinforcing a concrete structure, particularly a concrete structure capable of improving the shear strength of a surface member such as a wall or a floor on which a reinforcing material cannot be wound around the outer periphery.
A concrete structure is reinforced by providing a reinforced concrete member with a hole having an axial direction at a predetermined angle with respect to a surface of the reinforced concrete member; and extending in an axial direction of the hole. At least the first portion 11 of the reinforcing member 1 including the first portion 11 and the second portion 12 extending in a direction intersecting the axial direction of the hole 101 is disposed in the hole 101; Filling and fixing the reinforcing material 1.
[Selection] Figure 3

Description

【００３８】
尚、補強材１Ａの孔１０１の軸線方向に延びる補強部１１の長さ（図１の補強材１Ａでは補強材１Ａの長手長さ）Ｌ１は、通常、１００ｍｍ〜２０００ｍｍであるコンクリート壁１００の厚さＴと略同一とすることができる。要求される補強強度等によって種々変更されるものであるが、コンクリート壁１００の厚さＴの６０％〜１００％とすることで、施工性、補強効果共に好結果が得られる。
【００３９】
補強材１Ａを用いてコンクリート壁１００を補強するには、通常、コンクリート壁１００の複数箇所に孔１０１を設ける。要求される補強強度、既設鉄筋の配筋態様等によって種々変更されるものであるが、一般には、複数の孔１０１は、コンクリート壁１００の横方向（水平方向）の開口部中心間隔（Ｗ１）５０ｍｍ〜２０００ｍｍ、縦方向（垂直方向）の開口部中心間隔（Ｗ２）５０ｍｍ〜２０００ｍｍとして、好ましくは等間隔にて一様に配列する。当然、孔１０１は、コンクリート壁１００に埋設されている既設鉄筋１１０を避けて設けるのがよい。
【００４０】
図示の例では、コンクリート壁１００の略一様に平坦な一方の壁面（第１面）１００Ａから、その表面１００Ａに対して略垂直方向、即ち、コンクリート壁１００の略法線方向であって、コンクリート壁１００内の既設鉄筋（引張鉄筋、圧縮鉄筋）１１０の軸線方向と略直交する方向に沿い、反対側の壁面（第２面）１００Ｂまで貫通する孔１０１を、コンクリート壁の縦方向（垂直方向）、横方向（水平方向）のそれぞれにおいて複数箇所設けた。但し、孔１０１は、配置する補強材１Ａの補強部１１の長手長さなどに応じて一方の壁面、例えば第１面１００Ａから所定の深さまで設けることもできる。
【００４１】
ここで、コンクリート壁１００に設ける孔１０１の配向について説明する。図３（ａ）は、被補強コンクリート部材たるコンクリート壁１００の断面を模式的に示す。図示のコンクリート壁１００は、底版１００Ｃから垂直方向Ｖに起立しているものとする。そして、コンクリート壁１００に埋設された主筋（引張鉄筋、圧縮鉄筋）１１０は、図３（ａ）の紙面に垂直な方向に沿って配置されている。
【００４２】
例えば、図３（ａ）に示すようなコンクリート壁１００に、図中矢印Ｐ方向（図中右側面上方）に加力があり、例えばコンクリート壁１００にせん断補強筋がない場合、コンクリート壁１００には、ほぼ載荷点と支点（図示の例では、底版１００Ｃとの連結部）とを結ぶ線に沿って斜めひび割れ（せん断ひび割れ）Ｃが生じ、このひび割れが開口する方向に力が作用し、ついにはせん断破壊に至る。
【００４３】
載荷条件によって様々であるが、コンクリート壁１００に生じる斜めひび割れＣの軸線方向がコンクリート壁１００の法線方向Ｎに対して成す角度βは、通常、３０度〜６０度となる。
【００４４】
本発明に従う補強材１は、コンクリート壁１００に生じる斜めひび割れＣに働く力に対抗するように、補強部１１の軸線方向が斜めひび割れＣの軸線方向と交差する方向に設けることが好ましい。本発明者の検討によれば、図３（ｂ）に示すように、孔１０１の軸線方向Ｏがコンクリート壁１００の法線方向Ｎに対して成す角度αが、０度（即ち、法線方向Ｎ）〜６０度となるようにすれば、コンクリート壁１００のせん断耐力を良好に向上させることができる。角度αが６０度を超えると、補強材１が負担可能なせん断力が低下する、或いは補強材１の長さ及び孔１０１の長さが長くなるといった問題がある。但し、地震力のように正負２方向にせん断力が繰り返し作用することを考慮すると、より好ましくは、角度αは、０度〜４５度とし、更に好ましくは、角度αは０度、即ち、孔１０１の軸線方向Ｏがコンクリート壁１００の法線方向Ｎに沿うように孔１０１を設ける。
【００４５】
尚、角度αは、コンクリート壁１００の垂直方向Ｖと、コンクリート壁１００の法線方向Ｎで形成される平面内、即ち、コンクリート壁１００中の主筋と直交する平面内にある場合に限定されるものではない。但し、角度αがこの平面上にあるとき、孔１０１を設ける際の穿孔距離が最も短くなり、又より良好な補強効果を得ることができ、好ましい。即ち、これに限定するものではないが、図３（ｃ）に示すように、コンクリート壁１００をその法線方向Ｎから見た場合に、孔１０１の軸線がコンクリート壁１００の垂直方向Ｖと成す角度γは、好ましくは０度（即ち、垂直方向Ｖ）〜４５度、より好ましくは０度〜５度、更に好ましくは０度である。角度α及びγはせん断力の作用方向によって規定されるものであり、例えば被補強コンクリート部材が床面（底版）、頂版である場合など、面部材の配置によっては上記垂直方向Ｖは水平方向となる。上記垂直方向Ｖに相当する被補強コンクリート部材の配向は任意である。
【００４６】
以下、簡単のために、孔１０１は、上記角度αが０度で、角度γが０度であるとして説明する。
【００４７】
孔１０１の断面形状（孔１０１の軸線方向と直交する方向の断面。以下同様。）は、典型的には円形であるのが、これに限定されるものではない。孔１０１の断面寸法は、使用される補強材１Ａの断面寸法との関係で種々変更されるものであるが、断面略円形の補強材１Ａを使用する場合、通常、孔１０１の内径Ｄ２は補強材１Ａの補強部１１の外径より５〜５０ｍｍだけ大きくすることで、施工性、補強効果のいずれにおいても好結果が得られる。補強材１Ａの補強部１１の断面形状が略円形以外である場合でも、孔１０１の断面形状の長辺、短辺を、それぞれ補強材１Ａの補強部１１の断面形状の長辺、短辺の寸法よりも上記の通り大きくすればよい。勿論、補強材１Ａの断面形状の最大寸法よりも上記の通り大きい直径を有する孔１０１を穿孔してもよい。
【００４８】
充填材２としては、エポキシ樹脂、アクリル樹脂を含むコンクリート及び補強材１Ａと良好な接着性を持つ樹脂材料；ポリマーモルタル、ポリマーセメントモルタル、セメントモルタル、無収縮モルタル、膨張性モルタルを含むモルタル；ポリマーコンクリート、ポリマーセメントコンクリート、セメントコンクリート、無収縮性コンクリート、膨張性コンクリートを含むコンクリートなどを好適に使用することができる。膨張材が混合される膨張性モルタル又は膨張性コンクリートを使用すると、孔１０１の内部に挿入した補強材１Ａを、モルタル又はコンクリートの膨張圧による摩擦力で強固に定着させることが可能となる。
【００４９】
尚、本発明において、孔１０１への補強材１の配置と、孔１０１への充填材２の充填とは、この順序にて実施することに何ら限定されない。孔１０１に充填材２を注入した後、充填材２が硬化する前に補強材１をその孔に挿入して、孔１０１内にて補強材１の周囲が充填材２で充填された状態とし、その後補強材１を充填材２で固着するようにしてもよい。
【００５０】
上述のようにして、コンクリート壁１００に設けた孔１０１に補強材１を配置し、この補強材１を充填材２で固着することによって、極めて簡単な施工方法によって、コンクリート壁１００のせん断耐力を向上を図ることができる。
【００５１】
ところで、上述のように、実質的に孔１０１内に配置されてこの孔１０１の軸線方向に延びる棒状の第１部分（補強部）１１のみから成る補強材１Ａを、充填材２で固着することで、一定の補強効果が得られる。しかし、コンクリート壁１００の引張応力作用面（図１中矢印Ｐに示す方向に力が加わる場合、第１面１００Ａ）側では、補強材１Ａが孔１０１から抜け出すように力が加わり、補強効果が低下することがある。そこで、コンクリートに対する定着を向上するために、補強材１を以下に説明するような構成とする。
【００５２】
本発明によれば、補強材１をより強固に定着するために、補強材１は、孔１０１内でその軸線方向に延びる第１部分（補強部）１１と、孔１０１の軸線方向と交差する方向に延在する第２部分とを有する構成とする。本発明の一実施態様では、この第２部分は、第１部分（補強部）１１に連結されていると共に、孔１０１外でコンクリート壁１００の表面、特に、少なくともコンクリート壁１００の引張応力作用面に沿って配置される。
【００５３】
特に、本実施例では、補強材１は、図４に示すようにコンクリート壁１００に設けられた別個の孔１０１内にそれぞれ配置される複数の第１部分（補強部）１１を有し、そして、第２部分として、孔１０１外でコンクリート壁１００の表面に沿って配置され、複数の第１部分（補強部）１１を互いに連結する連結部１２を有するように構成する。
【００５４】
更に説明すると、このような補強材１は、図４に示すように、２つの補強部１１を連結部１２で連結した略Ｕ字形状の補強材１Ｂとして構成することができる。又、図５に示すように、３つの補強部１１を連結部１２で連結した山型の補強材１Ｃ、或いは更に多数の補強部１１（図示の例では５つ）を連結部１２で連結した櫛型の補強材１Ｄとすることができる。
【００５５】
このように、連結部１２を少なくともコンクリート壁１００の想定される引張応力作用面側に配置して複数の補強部１１を連結することで、この連結部１２が、引張応力作用面で機械的に補強材１を定着する定着部の効果を発揮し、補強材１によるコンクリート壁１００の補強効果を向上させることができる。
【００５６】
図４、図５に示す例では、複数の補強部１１はコンクリート壁１０１の縦方向に沿って配列された複数の孔１０１内に配置される。これにより、連結部１２は、コンクリート壁１００の縦方向に配向し、コンクリート壁１００内の既設鉄筋（引張鉄筋、圧縮鉄筋）１１０の軸線方向と略直交する方向に延びる。この場合、補強部１１の間隔は、コンクリート壁１００縦方向における孔１０１の開口部中心間隔Ｗ２と略同一とする。これにより、連結部１２の長さ（ここでは、補強部１１の間隔Ｗ２と略同一）に相当する長さＬ２の定着部を設けることができる。上記のように、孔１０１がコンクリート壁１００の法線方向Ｎに対して角度α（＞０）を有する場合には、複数の補強部１１の間隔は、孔１０１間の垂直距離（中心間距離）と略同一で、連結部１２の長さＬ２は、孔１０１の開口部中心間隔Ｗ２と略同一である。
【００５７】
尚、本実施例では、第２部分たる連結部（定着部）１２は、第１部分たる補強部１１に対して略直角に設けられているが、本発明はこれに限定されるものではない。第２部分は第１部分に対して交差する方向に設けられていればよく、例えば、図３を参照して説明したように、孔１０１がコンクリート壁１００の法線方向Ｎに対して角度α（＞０）を有する場合などには、第２部分は、第１部分に対して直角以外の角度で交差する。好ましくは、第２部分が第１部分に対して成す角度は、９０度±６０度の範囲内にあり、より好ましくは９０度±４５度、更に好ましくは９０度である。
【００５８】
又、連結部（定着部）の長さＬ２は、コンクリート壁１００の厚さＴ、補強材１（孔１０１）の配置態様などによって決まる。せん断補強筋のピッチは、通常、壁の厚さ以下で所用の耐力を得るのに必要な本数が確保できるように決定される。このようにして決められた補強材１（孔１０１）の配置態様に応じて、典型的には隣り合う孔１０１に配置される補強材１の補強部１１を連結する任意の長さの連結部１２を設けることによって、これを設けない場合と比較して飛躍的に定着効果が向上する。
【００５９】
連結部１２の配向をコンクリート壁１００の縦方向に沿う方向とすることは、補強部１１の引抜き耐力を向上させると共に、コンクリート壁１００の引張側面（図示の例では第１面１００Ａ）の破壊を防止する点で好ましい。但し、本発明はこれに限定されるものではない。
【００６０】
又、図６に示すように、コンクリート壁１００の縦方向に配列された複数の孔１０１内に配置される複数の補強部１１と、コンクリート壁１００の横方向に沿って配列された複数の孔１０１内にされる複数の補強部１１とを、縦方向連結部１２ａと横方向連結部１２ｂとによって互いに連結した補強材１Ｅを形成してもよい。この場合、補強部１１の縦方向の間隔、横方向の間隔は、それぞれコンクリート壁１００縦方向、横方向における孔１０１の間隔Ｗ２、Ｗ１と略同一とする。これにより、縦方向連結部１２ａ、横方向連結部１２ｂの長さ（ここでは、それぞれＷ２、Ｗ１と略同一。）にそれぞれ相当する長さＬ２ａ、Ｌ２ｂの定着部を設けることができる。
【００６１】
尚、補強部１１と連結部１２は、上述のような鉄筋、ＦＲＰ筋でそれぞれ溶接、成型などにより一体的に形成されるか、適当な連結手段によって接合されたものであってよい。ＦＲＰ筋であれば、マトリクス樹脂が未含浸の状態、或いは含浸されているが未硬化若しくは半硬化の状態で、任意の形状に比較的容易に成形することができる。
【００６２】
尚、上記では、第２部分は、複数の補強部１１を連結する連結部１２であるとして説明したが、これに限定されるものではない。図７に示すように、複数の補強部１１を有していないが、補強部１１と、この補強部１１に連結されて孔１０１外でコンクリート壁１００の表面に沿って配置される第２部分としての屈曲部１５（図示の例では補強部１１に対して略直角）を有する補強材１Ｆ、即ち、略Ｌ字形状の補強材１Ｆを構成してもよい。この場合、要求される補強強度等により種々変更されるものであるが、屈曲部（定着部）１５の長さＬ２は、補強部１１の断面形状の最大寸法（厚さ又は直径）の１倍〜１００倍、より好ましくは５倍〜２０倍とする。一般に、この長さＬ２は、２０ｍｍ〜２００ｍｍとすることで良好な定着効果が得られる。又、第２部分たる屈曲部１５は、第１部分たる補強部１１に対して略直角に設ける態様に限定されるものではなく、上記連結部（定着部）１２と同様に種々変更し得るものである。又、屈曲部１５は、一つの補強部１１に対して複数連結された態様でも何ら構わない。
【００６３】
更に、第１部分（補強部）１１に連結されていると共に、孔１０１外でコンクリート壁１００の表面に沿って配置され、定着部の作用を有する第２部分（連結部１２、屈曲部１５）は、棒状に延びたものに何ら限定されるものではない。例えば、図７に示すように、孔１０１の軸線方向と交差する方向に面状に延在する第２部分を設けてもよい。図示の例では、円盤状に延在する第２部分（連結部１２又は屈曲部１５）が、複数又は単一の第１部分（補強部）１１に連結された補強材１Ｂａ、１Ｆａを示す。面状に延在する第２部分は、例えば、溶接或いはボルト締結等の適当な手段により連結されるか或いは一体的に成形された鋼板或いはＦＲＰ板で形成することができる。
【００６４】
以上説明したように、本発明によれば、極めて簡単な施工方法によって、補強材を外周に巻き立てることが不可能なコンクリート壁１００のせん断耐力を向上させることができる。特に、本発明によれば、コンクリート壁１００の面外せん断力に対する補強効果を得ることができる。しかも、コンクリート壁１００がボックスカルバートの連続壁のように増厚による内容量の減少が問題となる場合であっても、断面寸法の大幅な増加を伴わずにせん断耐力を向上させることができる。
【００６５】
実施例２
次に、本発明の他の実施例について説明する。以下、実施例１におけるものと同一又は相当する機能、構成を有する要素には同一符号を付して詳しい説明は省略する。
【００６６】
補強材１としては、連続繊維補強材であるＦＲＰ格子材を用いることもできる。図２３を参照して説明すると、ＦＲＰ格子材２００は、通常、直角に交差して格子状に配置された複数の補強筋、即ち、縦補強筋２０１と横補強筋２０２で構成される。縦補強筋２０１、横補強筋２０２は、主にガラス繊維、炭素繊維、アラミド繊維等の強化繊維（上記ＦＲＰ筋と同様のものであってよい。）を一方向に並べて、ビニルエステル樹脂等のマトリクス樹脂（上記ＦＲＰ筋と同様のものであってよい。）を含浸させた帯状の強化繊維を複数積層して形成されたものである。又、縦補強筋２０１、横補強筋２０２は、筋幅（ｗ）３〜２０ｍｍ、厚さ（ｔ）１〜２０ｍｍであり、格子間距離（縦補強筋中心間距離、横補強筋中心間距離）（Ｗ３）２５〜２００ｍｍの格子板状に成形硬化され、全体としてシート状のＦＲＰ格子材２００を形成する。
【００６７】
又、使用されるＦＲＰ格子材２００の寸法、強度は、要求される補強強度、コンクリート壁１００への配筋態様に応じて種々変更することができるが、一般に、縦補強筋２０１、横補強筋２０２は、それぞれ引張強度５００Ｎ／ｍｍ^２〜２０００Ｎ／ｍｍ^２、引張弾性率２０ｋＮ／ｍｍ^２〜３００ｋＮ／ｍｍ^２のものが好ましく使用される。
【００６８】
本発明にて好適に使用し得るＦＲＰ格子材２００の一例を示せば、次の通りである。

【００６９】
このＦＲＰ格子材２００は、例えば、図８に示すように切り出して、本発明に従う補強材１として用いることができる。図８に示す補強材１Ｇは、実質的に孔１０１内に配置される部分のみから成る。更に説明すると、孔１０１の軸線方向に沿って配置される補強部１１と、孔１０１の軸線方向と交差する方向に延在する第２部分として、孔１０１内に配置されて補強部１１と交点１３を形成する突起部１４を有する。本実施例では、補強部１１は、孔１０１の軸線方向に沿って配置される縦補強筋２０１で形成され、突出部１４はこの縦補強筋２０１に略直交する横補強筋２０２で形成され、これらは孔１０１内で複数の交点１３を形成する。図示の例では、突出部１４は、交点１３において、縦補強筋２０１から成る補強部１１の両側に、孔１０１の軸線方向に略直交する方向に所定の突出量ｐにて突出するように、横補強筋２０２を切断することで形成されている。
【００７０】
このように、補強部１１がＦＲＰ格子材２００の縦補強筋２０１と横補強筋２０２との交点１３を少なくとも１つ有することで、孔１０１内でこの交点１３により補強材１の充填材２との付着が確保される。これにより、補強材１による補強効果が向上する。
【００７１】
突出部１４の孔１０１の軸線方向に直交する方向への突出量ｐは、補強部１１の断面形状の最大寸法（厚さ又は直径）の１／２〜５倍であることが好ましい。突出量ｐが上記範囲より少ない場合、突出部１４を設けることによる付着性の向上の効果は得られない。一方、突出量ｐが上記範囲を超えると、耐力がより向上することはなく、又孔１０１の径が大きくなるといった問題がある。従って、より好ましくは、突出量ｐは、補強部１１の断面形状の最大寸法（厚さ又は直径）の１／２〜２倍とする。使用するＦＲＰ格子材２００の筋幅（ｗ）、厚さ（ｔ）（或いは使用する補強材１の直径）等の寸法に応じて種々変更することができるが、突出量ｐは、通常、５ｍｍ〜２５ｍｍで施工性、補強効果、特に、補強材１の定着性の点で好結果が得られる。
【００７２】
尚、本実施例のように、補強部１１の両側に突出部１４を設けることにより（突出量２ｐ）、充填材２とのより良好な付着性を発揮することができるが、突出部１４は、補強部１１の一方の側面のみに設けてもよい。又、突出部１４は、補強部１１に略直交する方向に突出している態様に限定されるものではない。
【００７３】
図９には、ＦＲＰ格子材２００から形成される補強材１の他の実施例を示す。図９に示す補強材１Ｈは、孔１０１内に配置される２つの補強部１１と、これらを連結する連結部１２とを有し、全体として略Ｕ字型となるように切り出されたものである。補強部１１は、孔１０１の軸線方向に沿って配置される縦補強筋２０１から成り、連結部１２は、縦補強筋に略直交する横補強筋２０２から成る。更に、補強部１１には、孔１０１の軸線方向と交差する方向に延在する第２部分として、横補強筋２０２で形成される突出部１４が複数設けられており、補強部１１と突出部１４との複数の交点１３を形成している。図示の例では、突出部１４は、交点１３において、縦補強筋２０１から成る補強部１１の両側に、所定の突出量ｐにて突出するように横補強筋２０２を切断することで形成されている。
【００７４】
尚、図９に示す補強材１Ｈにおいては、補強部１１と連結部１２とはそれぞれＦＲＰ格子材２００の交差する縦補強筋２０１、横補強筋２０２で構成されるが、これに限定されるものではなく、例えば縦補強筋２０１を屈曲させて略Ｕ字型とすることによって、補強部１１と連結部１２とを縦補強筋２０１で形成することができる。
【００７５】
又、図１０には、３つの補強部１１が連結部１２で連結され、更に各補強部１１の両側に突出量ｐにて突出部１４が複数設けられた、全体として山型の補強材１Ｉを示す。補強部１１は更に多数設けてもよい。
【００７６】
更に、図１１には、縦方向及び横方向に配列された複数の補強部１１が、互いに連結部１２で連結され形状を有するように成形され、切り出された補強材１Ｊを示す。図示の例では、縦補強筋２０１を屈曲することにより、縦補強筋２０１から成る略Ｕ字型の３つの補強部１１が、それぞれ横補強筋２０２から成る３の連結部１２で連結された形状に成形されている。又、各補強部１１の両側に、突出量ｐにて複数の突出部１４が設けられている。
【００７７】
図８に示す補強材１Ｇは、図１に示すものと同様にしてコンクリート壁１００に設けた孔１０１に差し込むことができる。又、図９〜１１に示す補強材１Ｈ、１Ｉ、１Ｊは、それぞれ、図４〜６に示すものと同様にして、コンクリート壁１００に設けられた孔１０１に差し込むことができる。連結部１２をコンクリート壁１００の引張応力作用面に配置することにより、連結部１２の長さに相当する長さＬ２（図１１のものでは縦方向連結部１２ａ、横方向連結部１２ｂの長さにそれぞれ相当する長さＬ２ａ、Ｌ２ｂ）の定着部を設けることができ、上記同様の定着効果を得ることができる。
【００７８】
ＦＲＰ格子材２００から形成される補強材１を用いる場合、孔１０１は、一方向において筋幅ｗと突出量ｐとの合計である幅Ｗ４より５〜５０ｍｍだけ大きく、他の一方向においてＦＲＰ格子材２００の厚さｔより５〜５０ｍｍだけ大きい断面形状（矩形、楕円等）とすることで、施工性、補強効果のいずれにおいても好結果が得られる。勿論、孔１０１内に配置される補強材１の断面形状の最大寸法よりも上記の通り大きい直径を有する孔１０１を穿孔してもよい。
【００７９】
尚、ＦＲＰ格子材２００を用いて、図１２に示すように、複数の補強部を有していないが、補強部１１と、この補強部１１に連結されて孔１０１外でコンクリート壁１００の表面に沿って配置される第２部分としての屈曲部１５とを有する補強材１Ｋ、即ち、略Ｌ字形状の補強材１Ｋを構成してもよい。
【００８０】
又、上述のように、ＦＲＰ格子材２００は、縦補強筋２０１、横補強筋２０２を適宜切断などすることによって、容易に突起部１４を形成することができるため、突起部１４を有する補強材１を形成するのには好都合である。しかし、本発明はこれに限定されるものではなく、溶接鉄筋、或いは適当に成形されたＦＲＰ筋を用いることもできる。
【００８１】
実施例３
次に、本発明の他の実施例について説明する。上述のように、コンクリート壁１００の引張応力作用面に連結部１２を配置することによって、せん断補強効果が向上する。
【００８２】
本実施例では、更に、図１３に示すように、コンクリート壁１００の両面側、即ち、孔１０１の両端開口部から、実施例１にて説明したものと概略同様の略Ｕ字型の補強材１Ｂ、１Ｂ’を差し込む。この時、補強材１Ｂ、１Ｂ’の補強部１１が、各孔１０１内で重ね継手を形成するように、補強材１Ｂ、１Ｂ’を成形する。補強材１Ｂの強度、直径、充填材２の種類、或いはコンクリートの種類に応じて、両補強材１Ｂ、１Ｂ’間の十分な応力伝達が得られるような重ね長さＬ２を設ける。種々変更されるものであるが、通常、重ね長さＬ２は、補強材１の補強部１１の断面形状の最大寸法（厚さ又は直径）の５倍〜２０倍とすることで好結果が得られる。
【００８３】
このように補強材１Ｂ、１Ｂ’の重ね継手を設けて閉鎖系とすることによって、コンクリート壁１００に対して両面方向から力（図中矢印Ｐ、Ｐ’）が加わる正負交番載荷に対する補強効果を向上させることができる。
【００８４】
尚、上述では、鉄筋、ＦＲＰ筋からなる略Ｕ字型の補強材１Ｂを用いた場合について説明したが、図５、図６を参照して説明した他の形状のもの、或いは図９〜１１を参照して説明したＦＲＰ格子材から形成されたものを用いてもよいことは明らかである。又、上述のような略Ｌ字形状の補強材１Ｆ（若しくは補強材１Ｋ）（図７、図１２）、或いは面状の第２部分１２又は１５を有する補強材１Ｂａ又は１Ｆａ（図７）を、孔１０１の両側開口部から差し込み、継手を設ける構成としてもよい。図１４には、略Ｌ字形状の補強材１Ｆ、１Ｆ’を用いた例を示す。
【００８５】
実施例４
次に、本発明の他の実施例について説明する。例えば、地下構造物の底版、側壁などでは、構造物が地盤に埋設されており、構造物内部の一面のみからしか作業ができない場合がある。このような場合、地盤側のコンクリート面に引張応力が作用する場合であっても、地盤側から補強材１を挿入することができないか、困難である。そのため、例えば、図４に示すような定着効果を有する補強材１Ｂの連結部１２を、コンクリート壁１００の引張応力作用面に配置することができない。
【００８６】
図１５を参照すると、ここでは、ボックスカルバートの連続壁等とされるコンクリート壁１００の一方の面（第１面）１００Ａはボックスカルバートの内空間に面しているが、反対側面（第２面）１００Ｂは地盤Ｇに面している。この場合、第１面１００Ａ側からしか作業を行うことができないが、図示矢印Ｐ方向に加力がある場合には、第２面１００Ｂ側の下側に引張応力が作用する。
【００８７】
そこで、本実施例では、補強材１Ｌは、孔１０１内でその軸線方向に延びる補強部１１と、孔１０１の軸線方向と交差する方向に延在する第２部分として、この補強部１１に連結されていると共に、孔１０１外で少なくとも引張応力作用面に沿って配置される屈曲部１５を有する構成とする。本実施例では、補強部１１の軸線方向両端部に、補強部１１に対して略直角に延びる屈曲部１５を有するように成形する。ここでは、両屈曲部１５、１５間の間隔Ｗ５は、コンクリート壁１００の厚さＴとほぼ同じで、孔１０１内に配置される補強部１１の長さＬ１とほぼ同じとした。この屈曲部１５は、コンクリート壁の、特に、引張応力作用面に配置されることで、補強材１Ｌをコンクリート壁１００に定着させる定着部の効果を発揮する。
【００８８】
要求される補強強度等により種々変更されるものであるが、屈曲部（定着部）１５の長さＬ２は、上述のように、補強部１１の断面形状の最大寸法（厚さ又は直径）の１倍〜１００倍、より好ましくは５倍〜２０倍とする。一般に、この長さＬ２は、２０ｍｍ〜２００ｍｍとすることで好結果が得られる。
【００８９】
この場合、孔１０１は、コンクリート壁１００を貫通して、コンクリート壁１００の略法線方向に穿孔するが、孔１０１が断面略円形である場合、内径Ｄ４は、屈曲部１５の長さＬ２以上とされ、通常、内径Ｄ４は、屈曲部１５の長さＬ２より５〜５０ｍｍだけ大きくすることで、施工性、補強効果のいずれにおいても好結果が得られる。
【００９０】
尚、後述するように、補強材１Ｌの屈曲部１５を第２面１００Ｂに沿わせて配置するために、予め地盤Ｇまで余分に穿孔しておくことができる。
【００９１】
図１５に示すように、補強材１Ｌを、第１面１００Ａ側から孔１０１に差し込み、屈曲部１５が孔１０１の第２面１００Ｂ側開口部を通過したら、補強材１Ｌを、孔１０１の外周方向、即ち、コンクリート壁１００の第２面１００Ｂに沿う方向に、ここでは下方に移動させて、屈曲部１５が第２面１００Ｂにかかるように配置する。その後、孔１０１内に充填材２を充填して、補強材１Ｌを固定、定着させる。
【００９２】
図１６を参照すると、コンクリート壁１００の引張応力作用面側に地盤等の障害物が存在する場合に、その面に補強材１Ｌの屈曲部１５を配置する他の方法が示されている。ここでは、コンクリート壁１００に設ける孔１０１の断面形状を長方形又は楕円（図示の例では長方形）とする。孔１０１の断面の長辺の長さＬ４は、屈曲部１５の長さＬ２以上とされ、通常、長さＬ４は、屈曲部１５の長さＬ２より５〜５０ｍｍだけ大きくする。又、孔１０１の断面の短辺の幅Ｄ５を、補強材１Ｌの断面形状の最大寸法（厚さ又は直径）Ｄ１以上とされ、通常、幅Ｄ５は、補強材１Ｌの厚さ又は直径Ｄ１より５〜５０ｍｍだけ大きくする。これにより、ことで、施工性、補強効果のいずれにおいても好結果が得られる。
【００９３】
図１６に示すように、補強材１Ｌを、第１面１００Ａ側から孔１０１に差し込み、屈曲部１５が孔１０１をの第２面１００Ｂ側開口部を通過したら、屈曲部１５が第２面１００Ｂ上に来るように、補強材１Ｌを孔１０１の軸線方向の周りで回転させる。その後、孔１０１内に充填材２を注入して、補強材１Ｌを固定、定着させる。
【００９４】
このようにして、コンクリート壁１００の引張応力作用面側に地盤等の障害物が存在する場合にも、その面に屈曲部１５、即ち、定着効果を有する定着部を配置することで、補強材１Ｌの補強効果を向上させることができる。
【００９５】
ここで、補強材１Ｌの補強部１１の軸線方向両端部に屈曲部１５を設ける場合、屈曲部１５がコンクリート壁１００中の既設鉄筋を跨ぐように、即ち、補強材１Ｌを固定、定着した状態で、両方の屈曲部１５の間にコンクリート壁１００中の既設鉄筋が存在するように補強材１Ｌを配置することによって、補強材の引抜き耐力が向上するため、更に補強効果を向上させることができる。
【００９６】
尚、図１６に示す態様において、孔１０１の断面の長辺方向は、図示のように水平に制限されるものではなく他の如何なる角度であってもよい。
【００９７】
本実施例の補強材１Ｌは、上述のような鉄筋、ＦＲＰ筋等の棒状の補強筋、ＦＲＰ格子材のいずれで形成してもよい。又、上述したような略Ｌ字形状の補強材１Ｆ或いは１Ｋ（図７、図１２）、即ち、補強部１１の一端側に屈曲部１５が設けられている補強材１を用いて、その屈曲部１５側から孔１０１に挿入してもよい。
【００９８】
実施例５
次に、本発明の他の実施例について説明する。
【００９９】
以上の実施例において説明したように、コンクリート壁１００に孔１０１を設け、この孔に配置した補強材１を充填材２で固着することによって、コンクリート壁１００のせん断耐力を増加させることができる。
【０１００】
本実施例では、補強材１を更に強固に定着する方法について説明する。尚、ここでは、簡単のために、図１に示すような実質的に孔１０１内に配置される補強部１１のみから成る棒状の補強材１Ａの端部を定着する場合について説明するが、以下説明する定着方法は、上述して説明してきた本発明に従う補強材１について同様に適用し得るものである。
【０１０１】
図１７に示されるように、補強材１を挿入する孔１０１の端部に、孔１０１の軸線方向中心から、コンクリート壁１００の表面側に向けて拡幅した形状とする。これに限定されるものではないが、孔１０１が断面略円形であるとき、孔１０１は、上述のように小径部１０１Ａから、これより１０％〜１００％大きな大径開口部１０１Ｂへと、深さＬ５が２０〜２００ｍｍで漸次径が拡大する拡幅部１０１Ｃとを有するように穿孔される。
【０１０２】
これにより、例えば、図中矢印Ｐで示すように第１面１００Ａに力が加わり、孔１０１中の補強材１Ａを第１面１００Ａ側に引き抜く力が加わった場合、孔１０１の第２面１００Ｂ側の端部において、拡幅部１０１Ｃ内に充填された充填材２が楔効果により補強材１をコンクリート壁１００に強固に定着することが可能となる。斯かる楔作用をより効果的にするために、充填材２として膨張性モルタル、膨張性コンクリートを好適に使用し得る。
【０１０３】
図示の通り、孔１０１の軸線方向両端部にこのような拡幅部１０１Ｃを設けることによって、コンクリート壁１００の第１面１００Ａ、第２面１００Ｂのいずれに引張応力が作用した場合であっても、補強材１を強固に定着することができる。但し、これに限定されるものではなく、例えば、図４に示す補強材１Ｂのように、コンクリート壁１００の一方の表面側に定着部として作用する連結部（第２部分）１２を有する場合などにおいて、他方の表面側の孔１０１の開口部を上述の通り拡幅することで、正負交番載荷に対しての補強効果を向上することができる。
【０１０４】
又、補強材１の端部は、定着具によって定着することもできる。例えば、図１８に示すように、補強材１Ａの端部を、楔形状の定着具４０によって定着することができる。更に説明すると、例えば、孔１０１の補強材１の差し込み方向に楔定着具４０の楔４１を挿入し、上記同様の孔１０１の拡幅部１０１Ｃに楔４１を配置し（図１８（ａ））、次いで、孔１０１に補強材１を挿入する（図１８（ｂ））。更に、補強材１を拡幅部１０１Ｃに配置された楔４１を通して差し込み（図１８（ｃ））、補強材１を孔１０１内の所定の位置に配置する（図１８（ｄ））。
【０１０５】
これにより、楔定着具４０の楔作用によって、図１８（ｄ）中矢印方向へ補強材１を引き抜く力に対して、補強材１は強固に定着される。
【０１０６】
更に、図１８（ｄ）に示すように、楔４１の表面に、図中矢印方向への補強材１の移動を阻止するように補強材１の表面と係合する係止部４２を設けることによって、楔４１の定着効果を向上させることができる。この場合、楔４１の係止部４２は、補強材１が異形鋼或いは異形鋼状の表面を有するものでれば、その表面に設けられた突起に係合するようにしてもよいが、補強材１の楔定着具４０に対応する表面に楔４１の係止部と係合する受け部１６を加工してもよい。
【０１０７】
尚、孔１０１に拡幅部１０１Ｃが設けられていない場合であっても、上述のような楔定着具４０を使用することができる。
【０１０８】
加えて、例えば補強材１の上記楔定着具４０を設けた側とは反対側の端部を、更に、図１９に示すように、鋼製の定着板５１とナット５２を備えた一般的な定着具によって定着することができる。つまり、孔１０１の開口部上に定着板５１を配置し、定着板５１の開口部を貫通して延びる補強材１の表面に加工したねじにナット５２を螺合することによって定着する。
【０１０９】
以上のように、充填材２による固着に加えて、定着具（定着手段）を用いることにより、より一層強固に補強材１を定着することができる。
【０１１０】
実施例６
次に、本発明の他の実施例について説明する。上述のＦＲＰ筋は、孔１０１内に配置される以前に既にマトリクス樹脂が含浸され、硬化されたものであった。これに対して、本実施例では、ＦＲＰ筋は、孔１０１内で硬化される。
【０１１１】
図２０を参照して更に説明すると、先ず、所定本数の強化繊維（上記ＦＰＲ筋と同様のものであってよい。）を束ねた可撓性を有する強化繊維束２０を、マトリクス樹脂（上記ＦＲＰ筋と同様のものであってよい。）の含浸前にコンクリート壁１０１の孔１０１に挿入し、その後マトリクス樹脂２１を孔１０１に注入して強化繊維束に含浸させ、硬化させることで孔１０１内に配置されるＦＲＰ筋（補強材）１Ｍを形成する。その後、充填材２を孔１０１に充填してＦＲＰ筋とされた補強材１Ｍを孔１０１内に固着させる。
【０１１２】
強化繊維束２０としては、限定されるものではないが、実施例１にて説明したＦＲＰ筋を構成するものと同様の態様で集束されたものを用いることができる。
【０１１３】
或いは、強化繊維束２０としては、次のものを用いることができる。図２２に示すように、多数本の強化繊維ｆで構成される補強繊維束ｆ_０から成る強化繊維束２０は、この強化繊維束２０を囲包して配置された可撓性の管状被覆部材ｂの中心孔ｂ１内に配置することができる。管状被覆部材ｂと強化繊維束２０との間には、例えば十分な空隙を保持するなどして樹脂を注入し得るようにする。強化繊維束２０は、一般には、強化繊維ｆを平行状態に配列して作成される。即ち、所定本数の強化繊維ｆを平行或いは緩く撚りを掛けて集束して作製されるストランドＳを更に平行に或いは緩く撚りを掛けて複数本束ねることによって作製される。又、別法として、図２（ｃ）に示したようにして集束された補強繊維束ｆ_０と外層部材ｆ_１とから成る強化繊維束２０を、可撓性の管状被覆部材ｂ内に配してもよい。
【０１１４】
可撓性の管状被覆部材ｂは、用途によって種々の材料及びサイズのものとすることができ、一般に、中心孔ｂ１の内径が２〜１００ｍｍ、肉厚は０．０１ｍｍ〜５０ｍｍとされ、金属製とすることもできるが、樹脂材料で作製するのが好適である。好ましい樹脂材料としては、ポリエチレン、ポリプロピレン、ナイロン、塩化ビニール、ゴム系樹脂などを挙げることができる。又、管状被覆部材ｂは、充填材２との付着力を増大させるために、外表面に凹凸形状を設けることができる。凹凸形状としては、所定間隔でふし状に環状の起伏（或いは突起）を形成したり、螺旋状に起伏（或いは突起）を形成したりすることで設けることができる。管状被覆部材ｂ内に配置された強化繊維束２０は、コンクリート壁１００の孔１０１内に配置した後、管状被覆部材ｂ内にマトリクス樹脂を注入することで、樹脂が含浸される（このような補強材、樹脂の注入方法は、本発明者らが提案した強化繊維補強筋等に関する特開平１１−７０５９６号公報に詳しい。）。
【０１１５】
又、上述のようなマトリクス樹脂未含浸の強化繊維束２０の代わりに、予めマトリクス樹脂が含浸されているが、未硬化或いは半硬化状態の、所謂、プリプレグ状態の強化繊維束３０を孔１０１に挿入した後、孔１０１内で硬化させることによって、孔１０１内に配置されるＦＲＰ筋（補強材）１Ｍを形成してもよい。
【０１１６】
プリプレグ状態の強化繊維束３０を形成する場合も、限定されるものではないが、上記ＦＲＰ筋を構成するものと同様の態様で集束されたものとすることができる。この場合、マトリクス樹脂は、樹脂を収容した樹脂槽中に樹脂未含浸の強化繊維束を浸漬することなどによって含浸させることができる。
【０１１７】
或いは、上記のような管状被覆部材ｂ内に多数本の強化繊維ｆで形成される補強繊維束ｆ_０を配してプリプレグ状の強化繊維束３０を構成してもよく、この場合、コンクリート壁１００の孔１０１内に配置する以前に、管状被覆部材ｂの内部に予めマトリクス樹脂を注入し、この樹脂補強繊維束ｆ０へと含浸させてプリプレグ状態としておく。別法では、予め多数本の強化繊維ｆから成る補強繊維束ｆ_０に樹脂を含浸させた上で、その外側に可撓性を有する被覆材を巻き付けるか、射出成形などにより被覆層を形成することで、可撓性を有する管状被覆部材ｂ内に配置されたプリプレグ状の強化繊維束３０を得ることができる。
【０１１８】
ところで、強化繊維束２０、３０に含浸された樹脂は、放置することにより硬化するが、積極的にヒータなどの加熱手段により加熱することにより、その硬化を促進することができる。
【０１１９】
例えば、強化繊維束２０、３０を炭素繊維、金属線（金属繊維）などの導電性を有する繊維で構成する（全部が導電性を有する繊維であってもよい。）か、若しくは導電性を有する繊維を混合して構成し、これに通電して発熱させ、マトリクス樹脂を加熱硬化することができる。これにより、樹脂の硬化時間を短縮することができる。例えば、強化繊維束２０、３０を構成する強化繊維ｆが炭素繊維のように導電性を有する繊維であれば、これに通電して発熱させ、樹脂を加熱硬化することで、硬化時間を短縮することが可能となる。又、強化繊維束２０、３０の、好ましくは略中心位置に加熱部材としてヒータ線を配置し、ヒータ線に通電して発熱させ、樹脂を加熱硬化することができる。ヒータ線としては、例えばニクロム線、タングステン線、ニッケル線などが使用可能であり、線径０．１〜２０ｍｍの可撓性のあるものが好適である。
【０１２０】
上述のような、強化繊維束２０、３０は可撓性を有するため、極めて容易に任意の形状とすることができる。例えば、図２１に示すように、略Ｕ字形状として２つの孔１０１に挿入し、極めて簡便に、補強材１Ｍの補強部１１、連結部１２を形成することができる。
【０１２１】
或いは、このように可撓性を有する強化繊維束２０、３０は、図２１に示すように、一方の端部から他方の端部まで、複数の孔１０１に連続して配置することができる。図示の例では、先ず、コンクリート壁１００の一方の面（第１面）１００Ａ側から孔１０１ａに挿入された強化繊維束２０、３０は、次いで反対側の面（第２面）１００Ｂ側で次の孔１０１ｂに挿入される。更に、第１面１００Ａ側で次の孔１０１ｃに挿入された後、第２面１００Ｂ側で次の孔１０１ｄに挿入されて、第１面１００Ａ側開口部まで達する。これにより、簡単にコンクリート壁１００の第１面１００Ａ、第２面１００Ｂの両方において、補強材１Ｍの連結部１２を形成することができる。
【０１２２】
当然、強化繊維束２０、３０によって、図７に示して説明したような略Ｌ字形状の補強材Ｍを形成することもできる。
【０１２３】
ここで、強化繊維束の体積をＶ_Ｆ、強化繊維束に含浸された樹脂の量（体積）をＶ_Ｒ、Ｖ_Ｆ＋Ｖ_Ｒ＝Ｖ_Ｔとすると、樹脂充填率（％）、即ち、（Ｖ_Ｒ÷Ｖ_Ｔ）×１００は、５〜９０％となるように選定するのが好ましい。樹脂充填率が５％より少ないと、強化繊維と強化繊維との間で応力の伝達ができなくなり、結果として全体の引張強度が低下するといった問題があり、又、９０％より大きいと、繊維の量が相対的に少なくなり全体の引張強度が高くならないだけでなく、物理的に樹脂を含浸できないといった問題が発生する。従って、好ましくは、この樹脂充填率は３０〜８０％とされる。
【０１２４】
樹脂が未含浸の強化繊維束２０は、例えば、適当な単位のロール状として施工現場に搬送され、そこでコンクリート壁１００に設ける孔１０１の任意の孔間隔に対応して切断することができる。又、施工現場でこの強化繊維に樹脂を含浸させてプリプレグ状態の強化繊維束３０を作製し、用いることができる。或いは、マトリクス樹脂が予め含浸されたプリプレグ状態の強化繊維束３０を、例えば、適当な単位のロール状として施工現場に搬送してもよい。
【０１２５】
以上、本実施例のように可撓性を有する強化繊維束２０、３０を、孔１０１に配置した後効果させることで、上記各実施例と同様にコンクリート壁１００のせん補強効果を得ることができると共に、補強材１を施工現場で切断し、屈曲させるなどして、容易に任意の形状とすることができるので施工性がよい。
【０１２６】
実施例７
次に、本発明の更に他の実施例について説明する。本実施例は、面外せん断耐力に加えて、曲げ及び面内せん断力に対しても補強が要求される場合に、公知のコンクリート増厚工法と組み合わせる方法である。
【０１２７】
上述のように、上記各実施例にて説明した方法によれば、主にコンクリート部材の面外せん断耐力を向上させることができる。
【０１２８】
一方、従来、図２３に示すようなＦＲＰ格子材２００、又は例えば溶接にて格子状とされた鉄筋とされる格子材（以下、ここではＦＲＰ格子材２００を用いるものとする。）をコンクリート面にアンカーボルトで固定することによりコンクリート構造物に取り付け、その後セメントモルタル等を吹き付け、コテ塗りして被覆し、コンクリート面を増厚するか、或いは型枠を配置した後、生コンクリートを注入してＦＰＲ格子材とコンクリート構造物とを一体化させることによりコンクリート構造物を補強する方法がある。斯かる方法によって、主にコンクリート部材の曲げ耐力、面内せん断耐力を向上させることができる。
【０１２９】
そこで、本実施例では、図２４に示すように、被補強コンクリート部材としてのコンクリート壁１００の所定の位置に孔１０１を設け、コンクリート壁１００の表面にＦＲＰ格子材２００を配置する。そして、孔１０１外でコンクリート壁１００の表面に沿って配置される補強材１の第２部分、例えば、図４に示す補強材１Ｂの連結部１２によって、ＦＲＰ格子材２００（図示の例では、２本の横補強筋２０２）を固定するように、コンクリート壁１００の孔１０１に補強材１Ｂを差し込む。そして、孔１０１に充填材２を充填することによって補強材１Ｂを固定する。勿論、補強材１を挿入する以前に孔１０１内に充填材２を充填しておいてよいことは上述の通りである。
【０１３０】
これにより、従来用いられていた、コンクリート部材の補強効果に関しないアンカーボルトを用いることなく或いは使用量を減らして、補強材１でＦＲＰ格子材２００を固定することができる。
【０１３１】
その後、ＦＲＰ格子材２００、補強材１Ｂが設けられたコンクリート壁１００の表面にセメントモルタル、ポリマーモルタル、ポリマーセメントモルタルを含むモルタル、或いはセメントコンクリート、ポリマーコンクリート、ポリマーセメントコンクリートを含むコンクリートなどの増厚材３００を吹き付け、コテ塗りするなど、公知の方法で設けてコンクリート壁１００を増厚する。
【０１３２】
補強材１としては、上記連結部１２を有する補強材１の他、ＦＲＰ格子材２００を固定し得るように、コンクリート壁１００の表面方向に配置される第２部分を有するものであれば用いることもできる。
【０１３３】
尚、コンクリート壁１００の反対側面にもＦＲＰ格子材２００を設けるこができる。この場合、コンクリート壁１００の水平方向において異なる位置でコンクリート壁１００の表裏面から上述と同様にして補強材１Ｂを差し込み、固定してもよいが、例えば、図１３、図１４に示すように孔１０１内で継手を有するもの、或いは図１５、図１６に示すような補強部１１の両端に屈曲部１５を有するものを用いることができる。
【０１３４】
以上、本実施例によれば、補強材１を、コンクリート増厚工法と組み合わせて用いることで、コンクリート壁１００の面外せん断耐力に加えて、曲げ耐力及び面内せん断耐力の向上をも図ることができる。
【０１３５】
実験例１
本発明の補強方法の効果を立証するために、ＲＣ単純梁供試体をコンクリート壁部材にみたてて、２点支持２点静的載荷試験を行った。
【０１３６】
図２５を参照して、梁供試体５００の寸法は、幅（Ｗ０）３００ｍｍ、高さ（Ｈ０）４６０ｍｍ、長さ（Ｌ０）２７００ｍｍとされ、内部に引張鉄筋５０１、圧縮鉄筋５０２、スターラップ（支点位置のみ）５０３から成る鉄筋構造体を有するものであり、支点間距離（Ｌｓ）は２１００ｍｍ、荷重間距離（Ｌｐ）は３００ｍｍとした。コンクリートは、早強ポルトランドセメントを用いて、目標圧縮圧縮強度を３０Ｎ／ｍｍ^２として打設した。
【０１３７】
この供試体５００は、コンクリート打設１４日後に、上面５００Ａよりドリル（コアカッター）を用いて直径３０ｍｍの孔１０１を貫通させた。孔１０１は、供試体５００の長手軸線方向（主筋軸線方向）にほぼ直角、即ち、表面に対し略垂直方向である供試体５００の略法線方向に沿って設けた。又、孔１０１は、供試体５００の長手方向において、一方の支点から一方の載荷点の間に孔中心間距離（Ｌｒ１）１７５ｍｍで５箇所、又他方の支点から他方の載荷点の間に孔中心間距離（Ｌｒ２）１４０ｍｍで６箇所、又供試体５００の幅（Ｗ０）方向において間隔（Ｗｒ）１００ｍｍで２列、合計２２箇所設けた。供試体５００の幅Ｗ０方向において２列設ける孔１０１は、それぞれ表面から１００ｍｍ内側に配置した。そして、補強材１として図９に示すＦＲＰ格子材から形成したものを用い、補強材１の２つの補強部１１を、供試体５００の幅Ｗ０方向に設けた２つの孔にそれぞれ差し込んだ。補強材１を差し込んだ孔１０１に充填材２を充填し、７日間養生させた。孔中心間距離（Ｌｒ１）１７５ｍｍで孔１０１を設けたせん断スパンの片側を計測スパンとした。
【０１３８】
実験は、供試体５００の上面５００Ａから（供試体番号３）、下面５００Ｂから（供試体番号４）、又は上面及び下面５００Ａ、５００Ｂの両面から（供試体番号２）それぞれ補強材１を挿入した供試体と、補強材１を設けない無補強の供試体（供試体番号１）のそれぞれについて行った。補強材１、充填材２としては、次のものを用いた。
【０１３９】

計測項目は、主鉄筋ひずみ、ひび割れ発生状況、耐荷重及び供試体の変異とした。
【０１４０】
【表１】

【０１４１】
表１は、各供試体に関する最大荷重と破壊モードの結果を示す。無補強の供試体（供試体番号１）がせん断圧縮破壊、補強材１でせん断補強した３つの供試体（供試体番号２〜４）がいずれも曲げ圧縮破壊した。供試体番号２〜４では、最大荷重はほぼ同じ（５００ｋＮ）であった。いずれの供試体も約１００ｋＮで初期曲げひび割れが発生し、２５０ｋＮ前後で斜めひび割れが発生した。このように、せん断破壊する無補強の供試体が、補強材１によって曲げ破壊になったことによって、補強材１のせん断補強効果が確認できた。
【０１４２】
図２６に荷重変異曲線を示す。供試体番号２〜４では、等曲げ区間に曲げ圧縮破壊ひび割れが視認できたところで除荷した。図２６から、無補強の供試体（供試体番号１）に対して、最大荷重は、供試体番号２〜４のいずれにおいても３５％以上向上して曲げ破壊に到っていることから、せん断耐力は、供試体番号２〜４に対するいずれの補強方法であっても３５％以上向上することが確認された。
【０１４３】
このように、補強材１を孔１０１に差し込み、ボルト、ナット等の定着具により定着せず、樹脂定着することにより、せん断耐力を増加させ、破壊モードをせん断破壊から曲げ破壊に移行させることが可能であることが明らかとなった。
【０１４４】
図２７は、補強材１の測定ひずみから算定した、補強材１とコンクリートの負担せん断力を示す。この結果から、いずれの供試体でも、斜めひび割れの発生した荷重１３０ｋＮ（載荷荷重２６０ｋＮ）まではコンクリートがせん断力を負担し、斜めひび割れ発生以降、補強材１の負担せん断耐力Ｖｓが徐々に増加し、補強材１がせん断補強筋として機能していることが分かる。終局時の補強材１の負担せん断力は、補強材１の断面積の多い供試体番号２（上下面から）が最も大きく、次いで供試体番号４（下面から）が大きく、供試体番号３（上面から）が最も少なくなっている。
【０１４５】
図２７から、供試体番号３（上面から）、供試体番号４（下面から）、供試体番号２（上下面から）の順に、補強材１のせん断補強材としての効果が大きくなることが分かる。つまり、供試体５００の下面５００Ｂは、引張応力作用面であり、引張応力作用面に沿って補強材１の連結部（定着部）１２を配置することがより好ましいことが分かる。
【０１４６】
一方、上面５００Ａ側から補強材１を挿入した供試体番号３においてもせん断補強効果が見られることから、例えば、コンクリート壁面に沿う連結部２を有さず、実質的に孔１０１内に配置される部分のみから成る補強材１を用いることによっても本発明の効果が得られることが分かる。
【０１４７】
更に説明すると、供試体番号４（下面から）では、梁の引張面では連結部（横補強筋）１２による機械的定着と、樹脂による付着により定着され、圧縮領域である梁の上側では孔１０１内に樹脂による付着のみで定着されている。これに対して、供試体番号３（上面から）では、引張領域となる梁の下側で樹脂による付着のみ定着されている。この場合、圧縮領域では拘束効果により樹脂定着でも十分な定着強度が得られるが、引張領域では拘束効果がなく、逆にコンクリートと樹脂が剥離する方向にコンクリートに応力が作用する。上述の結果より、引張領域に連結部（即ち、コンクリート壁の表面に沿って配置される第２部分）による機械的な定着を提供することで、補強材１の定着をより確実にして、更に良好な補強効果を得られることが確認された。
【０１４８】
【発明の効果】
以上説明したように、本発明のコンクリート構造物の補強方法は、被補強コンクリート部材に、該被補強コンクリート部材の表面に対し軸線方向が所定の角度となる孔を設け；孔の軸線方向に延びる第１部分と、孔の軸線方向と交差する方向に延在する第２部分と、を備える補強材の少なくとも第１部分を孔内に配置し；孔に充填材を充填して補強材を固定する；ことを含む構成とされるので、
（１）コンクリート構造物、特に、補強材を外周に巻き立てることが不可能な壁、床などの面部材のせん断耐力を向上させることができる。
（２）コンクリート構造物、特に、面部材のせん断耐力を向上させることができ、且つ、コンクリート増厚工法のように断面寸法の大幅な増加を伴わず、しかも施工が容易である。
といった作用効果を奏し得る。
【０１４９】
又、本発明のコンクリート構造物の補強方法は、更に、前記被補強コンクリート部材の表面に沿って、連続繊維を複数層交差させて交点が形成された繊維強化プラスチック格子材又は格子状に配された鉄筋から成る格子材を配置し；前記孔に前記補強材を配置する際に、前記補強材の前記第２部分で、前記格子材を前記被補強コンクリート部材の表面に固定し；前記格子材を固定した前記被補強コンクリート部材の表面をモルタル又はコンクリートで増厚することを含むことで、（３）主に曲げ耐力、面内せん断耐力を向上させ得るコンクリート増厚工法と共に用いることができ、簡便に該コンクリート部材の面外せん断耐力を向上させることができる。
といった効果をも奏し得る。
【図面の簡単な説明】
【図１】本発明に係るコンクリート構造物の補強方法の原理を説明するためのコンクリート壁の斜視図である。
【図２】補強材の一実施例を示す斜視図である。
【図３】コンクリート壁の穿孔方向を説明するための説明図である。
【図４】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図５】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図６】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図７】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図８】補強材の他の実施例を示す斜視図である。
【図９】補強材の他の実施例を示す斜視図である。
【図１０】補強材の他の実施例を示す斜視図である。
【図１１】補強材の他の実施例を示す斜視図である。
【図１２】補強材の他の実施例を示す斜視図である。
【図１３】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図１４】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図１５】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図１６】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図１７】本発明に係るコンクリート構造物の補強方法に適用し得る補強材の定着方法の一実施例を示す断面図である。
【図１８】本発明に係るコンクリート構造物の補強方法に適用し得る補強材の定着方法の他の実施例を示す要部断面図である。
【図１９】本発明に係るコンクリート構造物の補強方法に適用し得る補強材の定着方法の他の実施例を示す断面図である。
【図２０】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図２１】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図２２】補強材の更に他の実施例を示す斜視図である。
【図２３】補強材を形成するＦＲＰ格子材を説明するための斜視図である。
【図２４】本発明に係るコンクリート構造物の補強方法の他の実施例を説明するためのコンクリート壁の斜視図である。
【図２５】本発明の効果を示すために用いた供試体の説明図である。
【図２６】本発明の効果を示す荷重変異曲線のグラフ図である。
【図２７】本発明の効果を示す負担せん断力のグラフ図である。
【符号の説明】
１（１Ａ〜１Ｍ） 補強材
２ 充填材
１１ 補強部（第１部分）
１２ 連結部（第２部分）
１５ 屈曲部（第２部分）
２０ 強化繊維束
３０ プリプレグ状の強化繊維束
１００ コンクリート壁（被補強コンクリート部材）
１０１ 孔[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a concrete structure, and more particularly to a method for reinforcing a concrete structure suitable for reinforcing a surface member such as a wall or a floor where a reinforcing material cannot be wound around the outer periphery.
[0002]
[Prior art]
In recent years, reinforcement for the purpose of improving earthquake resistance has been demanded not only for newly constructed concrete structures but also for existing concrete structures in terms of enhancing earthquake resistance.
[0003]
For example, seismic reinforcement of existing water and sewage facilities often requires reinforcement against the out-of-plane shear force of RC (steel reinforced concrete) walls. This is because the RC wall designed according to the old standard is not provided with sufficient shear reinforcement. In particular, some seismic design of sewer box culvert walls before 1998 does not consider out-of-plane shear, and such box culvert walls have almost no shear reinforcement.
[0004]
Conventionally, there are a continuous fiber sheet bonding method, a steel plate bonding method, a concrete (or mortar) thickening method (hereinafter referred to as a “concrete thickening method”) and the like for bending reinforcement of beams, columns, and walls. The steel plate bonding method is a method in which a steel plate is fixed to a concrete surface with an anchor and an adhesive is injected. The continuous fiber sheet bonding method is a method in which a sheet-like continuous fiber sheet obtained by impregnating a high-strength reinforcing fiber such as carbon fiber with a room temperature curing type epoxy resin is attached to a concrete surface with an adhesive resin and cured. The concrete thickening method is generally a sheet-like fiber reinforced plastic (FRP) lattice material (continuous fiber reinforcement) composed of a plurality of longitudinal reinforcement bars and transverse reinforcement bars arranged in a lattice pattern crossing at right angles. Reinforcing bars (welded reinforcing bars) arranged in a grid are fixed to the concrete surface with anchor bolts and then attached to the concrete structure. Then, cement mortar, cement concrete, etc. are sprayed and coated with a trowel to increase the concrete surface. It is a method of thickening or thickening the concrete surface with cement mortar, cement concrete or the like without using reinforcing bars.
[0005]
Further, a continuous fiber sheet winding method, a steel plate winding method, and an RC winding method are widely used for shear reinforcement of beams and columns. The continuous fiber sheet winding method is a method of obtaining a reinforcing effect by, for example, winding a reinforcing fiber sheet around a concrete column and curing the matrix resin impregnated in the fiber. The steel plate winding method is a method in which a steel plate is wound around a concrete column, and the attached steel plates are welded together or bolted together to fill a space between the concrete and the steel plate with resin or mortar. The RC hoisting method is a method of increasing the thickness by increasing the reinforcing bars around the existing concrete columns and placing concrete.
[0006]
On the other hand, as a reinforcement method for the out-of-plane shear force of the surface member, an upper surface thickening method for the purpose of improving the punching shear strength of the RC floor slab has been studied. In addition, as a method for reinforcing an out-of-plane shear force such as a side wall of a box culvert, a method of increasing the thickness of the concrete inside the wall is employed. In this case, the concrete surface is generally thickened with cement mortar, cement concrete or the like without providing reinforcing bars in the normal direction of the wall.
[0007]
[Problems to be solved by the invention]
However, when it is attempted to improve the shear strength, particularly the out-of-plane shear strength, by increasing the thickness of the concrete, the cross-sectional area increases greatly. For example, in the tank structure, the reduction of the internal volume becomes a problem. In other words, when trying to reinforce the out-of-plane shear force by increasing the thickness of the concrete, the thickened concrete is integrated with the existing concrete to bear the shearing force and exert the reinforcing effect. It is generally determined by the insufficient shear force and becomes very thick.
[0008]
As described above, when attempting to shear-reinforce a box culvert wall with almost no shear reinforcements by increasing the thickness of the concrete, it is necessary to double the member thickness. This reduces the inner cross section and is not effective.
[0009]
In addition, if it is attempted to reinforce the out-of-plane shear force by increasing the thickness of the concrete, it is necessary to increase the thickness of the concrete on the compression side, and construction is often difficult on the side walls, bottom plates, and top plates of underground structures. . Furthermore, the increase in mass is large, which may adversely affect the foundation. In addition, there is a problem that the curing period is long and the construction period is long in order to place concrete.
[0010]
On the other hand, the continuous fiber sheet bonding method has a problem that the continuous fiber sheet has almost no shear rigidity and proof strength, and a large increase in proof strength against the out-of-plane shear force of the face member cannot be expected.
[0011]
By the way, in the concrete thickening method using the above-mentioned continuous fiber reinforcing material or reinforcing bar, the reinforcing bar bears the load, and mainly the bending strength and in-plane shear strength of the concrete member can be improved. That is, in this case, the reinforcing effect is mainly exerted by the reinforcing bar, and the thickened concrete or mortar serves as a binder for fixing the reinforcing bar to the existing member. Therefore, in this method, the thickness of the concrete to be increased may be about the minimum thickness determined from the cover of the reinforcing bar. However, in this method, since the reinforcing bars do not bear the shearing force except when the reinforcing bars are wound around the outer periphery like a column member, the out-of-plane shear reinforcing effect is small.
[0012]
Accordingly, an object of the present invention is to provide a method for reinforcing a concrete member that can improve the shear strength of a surface member such as a wall or a floor where a concrete structure, in particular, a reinforcing material cannot be wound around the outer periphery. That is.
[0013]
Another object of the present invention is to improve the shear strength of a concrete structure, in particular, a face member, and is not accompanied by a significant increase in cross-sectional dimensions as in the concrete thickening method, and is easy to construct. It is to provide a method for reinforcing a concrete member.
[0014]
Furthermore, the other object of the present invention can be used together with a concrete thickening method using a continuous fiber reinforcing material or a reinforcing bar which can mainly improve bending strength and in-plane shear strength. It is an object of the present invention to provide a method for reinforcing a concrete structure capable of improving shear strength.
[0015]
[Means for Solving the Problems]
The above object is achieved by the method for reinforcing a concrete structure according to the present invention. In summary, according to the present invention, the reinforced concrete member is provided with a hole whose axial direction is a predetermined angle with respect to the surface of the reinforced concrete member; a first portion extending in the axial direction of the hole; A second portion extending in a direction crossing the axial direction; and at least the first portion of the reinforcing member provided in the hole; filling the hole with a filler to fix the reinforcing member; It is the reinforcement method of the concrete structure characterized by including. According to a preferred embodiment of the present invention, the hole is provided so that an axial direction of the hole is within 60 degrees with respect to a normal direction of the reinforced concrete member.
[0016]
According to an embodiment of the present invention, the second portion includes a fixing portion that is connected to the first portion and disposed along the surface of the reinforced concrete member outside the hole. In one embodiment, when the hole is provided, the hole is provided through the reinforced concrete member; and when the reinforcing material is disposed in the hole, the hole is provided from the end where the fixing portion is provided. After inserting the reinforcing material into the hole, the reinforcing material is moved in the direction along the surface of the concrete member to be reinforced, or rotated around the axial direction of the hole, and the fixing portion is moved to the concrete member to be reinforced. Place along the surface. According to a preferred embodiment, the fixing portions are provided at both ends of the reinforcing material, and preferably between the fixing portions provided at both ends of the reinforcing material, in the reinforced concrete member. The reinforcing material is arranged in the hole of the reinforced concrete member so that existing reinforcing bars exist. According to another embodiment of the present invention, the reinforcing member has a plurality of the first portions respectively disposed in the separate holes provided in the reinforced concrete member, and the fixing portion includes A plurality of first portions are connected to each other, and a connecting portion is provided outside the hole and along the surface of the reinforced concrete member. In a preferred embodiment of the present invention, the reinforcing member has a substantially U shape in which the two first parts are connected by the connecting part, and a substantially mountain shape in which the three first parts are connected by the connecting part, Or it is set as the substantially comb shape which connected the said 1st part of four or more by the said connection part. In one preferred embodiment, when the hole is provided, the hole is provided through the reinforced concrete member; when the reinforcing material is disposed in the hole, the hole is provided from both side openings of the hole. Reinforcing material is inserted and arranged so that at least a part of both reinforcing materials overlaps in the hole; when the reinforcing material is fixed by the filler, a stack of reinforcing materials inserted from both side openings of the hole Form a joint.
[0017]
According to another embodiment of the present invention, the second part has a protrusion that is disposed in the hole and forms an intersection with the first part in the hole. In one embodiment, the reinforcing material has a plurality of the protrusions. According to a preferred embodiment, the protruding amount of the protrusion from the first portion in the direction orthogonal to the axial direction of the hole is the cross-sectional shape of the first portion in the direction orthogonal to the axial direction of the hole. 1/2 to 5 times the maximum dimension.
[0018]
In one embodiment of the present invention, the reinforcing material is formed of a metal or fiber reinforced plastic rod. In another embodiment of the present invention, the reinforcing material is formed of a fiber reinforced plastic lattice material in which intersections are formed by crossing a plurality of continuous fibers.
[0019]
According to one embodiment of the present invention, when the hole is provided, the end of the hole has a shape in which the diameter is increased from the center of the reinforced concrete member toward the surface in the axial direction of the hole. Can do. Furthermore, the reinforcing material may be fixed by a fixing tool at at least one end of the hole. In a preferred embodiment, the fixing device is a wedge-type fixing device that is inserted into an end portion of the hole to perform a wedge action, and preferably, the wedge fixing device is a locking portion that engages with the reinforcing material. Have
[0020]
According to another embodiment of the present invention, when the reinforcing material is disposed in the hole, after inserting the reinforcing fiber bundle having flexibility into the hole, the resin is applied to the reinforcing fiber bundle in the hole. The reinforcing material made of fiber reinforced plastic can be formed by impregnation and curing. Alternatively, in another embodiment of the present invention, when the reinforcing material is disposed in the hole, a flexible reinforcing fiber bundle that is already impregnated with a resin but is uncured or semi-cured. After the resin is inserted into the hole, the resin can be cured in the hole to form the reinforcing material made of fiber reinforced plastic. In one embodiment, the reinforcing fiber bundle is composed of conductive fibers or mixed with conductive fibers, and when the resin is cured, the conductive fibers are energized. The resin is cured by generating heat. And according to a preferred embodiment, when the reinforcing material is disposed in the hole, the reinforcing fiber bundle is disposed in two holes provided in the reinforced concrete member as a substantially U shape, Or it arrange | positions continuously in three or more holes.
[0021]
In the present invention, the filler is a resin; cement mortar, polymer cement mortar, polymer mortar mortar, non-shrink mortar, expandable mortar; cement concrete, polymer cement concrete, polymer concrete, non-shrinkable concrete, expandable It may be concrete including concrete. The reinforced concrete member may be a surface member including a box culvert wall.
[0022]
According to still another embodiment of the present invention, the method for reinforcing a concrete structure further includes a fiber-reinforced plastic lattice material in which intersections are formed by crossing a plurality of continuous fibers along the surface of the concrete member to be reinforced. A lattice material, which is a reinforcing bar arranged in a lattice shape, is disposed; when the reinforcing material is disposed in the hole, the lattice material is fixed to the surface of the reinforced concrete member at the fixing portion of the reinforcing material. And thickening the surface of the reinforced concrete member to which the lattice material is fixed with mortar or concrete.
[0023]
According to another aspect of the present invention, the reinforced concrete member is provided with a hole whose axial direction has a predetermined angle with respect to the surface of the reinforced concrete member; a flexible reinforcing fiber bundle is inserted into the hole. Thereafter, the reinforcing fiber bundle is impregnated with resin in the hole and cured to form a reinforcing material made of fiber reinforced plastic; and the reinforcing material is fixed by filling the hole with the filling material. A method for reinforcing a concrete structure is provided.
[0024]
According to yet another aspect of the present invention, the reinforced concrete member is provided with a hole whose axial direction is at a predetermined angle with respect to the surface of the reinforced concrete member; the resin is already impregnated but the resin is uncured Alternatively, after inserting a flexible reinforcing fiber bundle in a semi-cured state into the hole, the resin is cured in the hole to form a reinforcing material made of fiber reinforced plastic; A method for reinforcing a concrete structure is provided, including filling and fixing the reinforcing material.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a concrete structure reinforcing method according to the present invention will be described in more detail with reference to the drawings.
[0026]
Example 1
The reinforcing method of the present invention can be suitably applied to seismic reinforcement of a concrete member to be reinforced constituting a concrete structure, in particular, a surface member such as a wall or a floor where the reinforcing material cannot be wound around the outer periphery. Of course, the present invention is not limited to this, and can be applied to reinforcement of beams, columns, girders, and the like.
[0027]
FIG. 1 is a schematic view of a reinforced concrete member for explaining the principle of the concrete structure reinforcing method of the present invention. The present invention is applied to reinforcement of a concrete wall 100 such as a continuous wall of a box culvert. Hereinafter, the concrete wall 100 as the reinforced concrete member is described as a side wall standing upright from the bottom plate, but the same applies to the reinforced concrete member being the bottom plate and the top plate.
[0028]
According to the present invention, first, the concrete wall 100 is drilled by a suitable means such as a drill, and the hole 101 is provided in the concrete wall 100. As will be described in detail later, the hole 101 is preferably provided along the substantially normal direction of the concrete wall 100. The reinforcing material 1 is inserted into the hole 101 and disposed. Then, the reinforcing material 1 is fixed by filling the filling material 2 into the hole 101 in which the reinforcing material 1 is arranged.
[0029]
A reinforcing member 1A shown in FIG. 1 is substantially composed of only a first portion (reinforcing portion) 11 disposed in the hole 101 and extending in the axial direction of the hole 101, and has a substantially rod shape. As the reinforcing material 1A, a metal, typically a steel bar, that is, a steel bar for reinforced concrete (hereinafter simply referred to as “rebar”), or a fiber reinforced plastic (FRP) bar which is a continuous fiber reinforcing material. A material, that is, an FRP line can be preferably used.
[0030]
In the case of using a reinforcing bar, it may be either a round steel or a deformed steel provided with undulations (or protrusions) of any appropriate shape on the outer periphery. Shaped steel is preferred from the viewpoints of adhesion and fixing properties with the filler 2 described later. In addition, the size and strength of the reinforcing bars used as the reinforcing material 1A can be variously changed according to the required reinforcing strength and the arrangement of the reinforcing bars on the concrete wall 100. In general, the tensile strength is 300 N / mm. ² ~ 600N / mm ² , Tensile elastic modulus 190kN / mm ² ~ 210kN / mm ² Those having an outer diameter of 6 mm to 51 mm are preferably used. In addition, examples of the metal reinforcing material 1A include stainless steel bolts.
[0031]
On the other hand, if FRP reinforcement is used as the reinforcing material 1A, it is preferable in terms of light weight, high strength, corrosion, and nonmagnetic properties. In particular, it is advantageous because it is resistant to corrosion due to acid, alkali, and salt, and has excellent durability, which is a concern when using steel materials.
[0032]
The FRP streak is produced by impregnating a matrix resin into a large number of continuous reinforcing fibers and converging them into a rod shape, followed by curing. That is, referring to FIG. 2, a reinforcing fiber bundle is obtained by bundling a plurality of strands S that are produced by converging a predetermined number of reinforcing fibers f in parallel or loosely by twisting them in parallel or loosely. Is formed, impregnated with a matrix resin, and cured.
[0033]
The FRP bars may be round steel, but, for example, as shown in FIG. 2 (a), the FRP bars are formed into a deformed steel bar shape with an arbitrarily shaped undulation (or protrusion) a provided on the outer periphery. May be good. Further, as shown in FIG. 2 (b), a plurality of strands S produced by concentrating reinforcing fibers f in parallel or loosely twisted strands are actively bundled in a spiral manner in the axial direction. Alternatively, a reinforcing fiber bundle formed into a PC steel stranded wire shape may be used. Further, as shown in FIG. 2 (c), a predetermined number of reinforcing fibers f are bundled in parallel or loosely twisted strands S to be produced by bundling a plurality of strands S in parallel or loosely twisted. Reinforcing fiber bundle f ₀ Are further bundled or enclosed, and a braided body made of a reinforcing fiber f ′ of the same or different quality as the reinforcing fiber f, or a tape made of fiber or resin of the same or different quality as the reinforcing fiber f Outer layer member f ₁ (FRP reinforcing bars such as this are well known in JP-A-11-124957 relating to reinforcing fiber reinforcing bars proposed by the present inventors). . A reinforcing fiber bundle can also be formed by weaving reinforcing fibers. The reinforcing material 1A provided with the deformed steel shape or the outer layer f1 is preferable in terms of adhesion and fixing properties with the filler 2 described later.
[0034]
Reinforcing fibers include carbon fibers, glass fibers, ceramic fibers, and boron fibers; aramid fibers, polyester fibers, polyethylene fibers, polypropylene fibers, nylon fibers, vinylon fibers, polyacetal fibers, PBO fibers, and polyacrylate fibers Organic fibers; or metal fibers including titanium fibers, stainless steel fibers, and iron fibers can be used singly or in combination. Usually, as the reinforcing material 1A for the concrete structure, carbon fibers can be preferably used, and any type of carbon fibers such as PAN-based, pitch-based, and the like may be used.
[0035]
As the matrix resin, any of vinyl ester resin, unsaturated polyester resin, polyamide resin, room temperature curable polyester resin, thermosetting epoxy resin, polycarbonate resin, MMA (methyl methacrylate) resin, urethane resin, acrylic resin, or A mixture of two or more of these can be used.
[0036]
In addition, the size and strength of the FRP bars used as the reinforcing material 1A can be variously changed according to the required reinforcing strength and the arrangement of the reinforcing bars on the concrete wall 100. In general, the tensile strength is 500 N / mm. ² ~ 5000N / mm ² , Tensile modulus 20kN / mm ² ~ 500kN / mm ² Those having an outer diameter of 5 mm to 100 mm are preferably used.
[0037]
An example of the FRP muscle that can be suitably used in the present invention is as follows.

[0038]
Note that the length L1 of the reinforcing portion 11 extending in the axial direction of the hole 101 of the reinforcing material 1A (longitudinal length of the reinforcing material 1A in the reinforcing material 1A in FIG. 1) L1 is usually 100 mm to 2000 mm. The length T can be substantially the same. Although various changes are made depending on the required reinforcement strength and the like, when the thickness T of the concrete wall 100 is 60% to 100%, good results can be obtained in both workability and reinforcement effect.
[0039]
In order to reinforce the concrete wall 100 using the reinforcing material 1 </ b> A, holes 101 are usually provided at a plurality of locations on the concrete wall 100. Although various changes are made depending on the required reinforcement strength, the arrangement of the existing reinforcing bars, etc., generally, the plurality of holes 101 have a center interval (W1) in the lateral direction (horizontal direction) of the concrete wall 100. The openings are arranged uniformly at equal intervals, preferably 50 mm to 2000 mm, and the opening center distance (W2) in the vertical direction (vertical direction) 50 mm to 2000 mm. Naturally, the hole 101 is preferably provided avoiding the existing reinforcing bar 110 embedded in the concrete wall 100.
[0040]
In the example shown in the drawing, from one wall surface (first surface) 100A of the substantially uniform flat surface of the concrete wall 100, the surface is substantially perpendicular to the surface 100A, that is, the substantially normal direction of the concrete wall 100, A longitudinal direction (vertical direction) of the concrete wall passes through a hole 101 that penetrates to the opposite wall surface (second surface) 100B along a direction substantially orthogonal to the axial direction of the existing reinforcing bars (tensile reinforcing bars, compression reinforcing bars) 110 in the concrete wall 100. Direction) and a lateral direction (horizontal direction). However, the hole 101 can be provided from one wall surface, for example, the first surface 100A to a predetermined depth according to the longitudinal length of the reinforcing portion 11 of the reinforcing member 1A to be arranged.
[0041]
Here, the orientation of the holes 101 provided in the concrete wall 100 will be described. Fig.3 (a) shows typically the cross section of the concrete wall 100 which is a to-be-reinforced concrete member. It is assumed that the illustrated concrete wall 100 stands in the vertical direction V from the bottom plate 100C. And the main reinforcement (tensile reinforcement, compression reinforcement) 110 embed | buried under the concrete wall 100 is arrange | positioned along the direction perpendicular | vertical to the paper surface of Fig.3 (a).
[0042]
For example, when a concrete wall 100 as shown in FIG. 3A has a force in the direction of arrow P (upward on the right side in the figure) in the figure, and the concrete wall 100 has no shear reinforcement, for example, Is an oblique crack (shear crack) C along a line connecting the loading point and the fulcrum (in the example shown, the connecting portion with the bottom plate 100C), and a force acts in the direction in which the crack opens. Leads to shear failure.
[0043]
The angle β formed by the axial direction of the oblique crack C generated in the concrete wall 100 with respect to the normal direction N of the concrete wall 100 is usually 30 to 60 degrees, although it varies depending on the loading conditions.
[0044]
The reinforcing material 1 according to the present invention is preferably provided in a direction in which the axial direction of the reinforcing portion 11 intersects the axial direction of the oblique crack C so as to counteract the force acting on the oblique crack C generated in the concrete wall 100. According to the study of the present inventor, as shown in FIG. 3B, the angle α formed by the axial direction O of the hole 101 with respect to the normal direction N of the concrete wall 100 is 0 degree (that is, the normal direction). N) to 60 degrees can improve the shear strength of the concrete wall 100 satisfactorily. When the angle α exceeds 60 degrees, there is a problem that the shearing force that can be borne by the reinforcing material 1 is reduced, or the length of the reinforcing material 1 and the length of the hole 101 are increased. However, considering that the shearing force repeatedly acts in two positive and negative directions like seismic force, the angle α is more preferably 0 ° to 45 °, and still more preferably the angle α is 0 °, that is, the hole The hole 101 is provided so that the axial direction O of 101 is along the normal direction N of the concrete wall 100.
[0045]
The angle α is limited to a case where the angle α is in a plane formed by the vertical direction V of the concrete wall 100 and the normal direction N of the concrete wall 100, that is, in a plane orthogonal to the main reinforcement in the concrete wall 100. It is not a thing. However, when the angle α is on this plane, the drilling distance when the hole 101 is provided is the shortest, and a better reinforcing effect can be obtained, which is preferable. That is, although not limited to this, as shown in FIG. 3C, when the concrete wall 100 is viewed from its normal direction N, the axis of the hole 101 forms the vertical direction V of the concrete wall 100. The angle γ is preferably 0 degrees (that is, the vertical direction V) to 45 degrees, more preferably 0 degrees to 5 degrees, and still more preferably 0 degrees. The angles α and γ are defined by the acting direction of the shearing force. For example, when the concrete member to be reinforced is a floor surface (bottom plate) or a top plate, the vertical direction V is a horizontal direction depending on the arrangement of the surface members. It becomes. The orientation of the reinforced concrete member corresponding to the vertical direction V is arbitrary.
[0046]
Hereinafter, for the sake of simplicity, the hole 101 will be described assuming that the angle α is 0 degrees and the angle γ is 0 degrees.
[0047]
The cross-sectional shape of the hole 101 (the cross section in the direction orthogonal to the axial direction of the hole 101; hereinafter the same) is typically circular, but is not limited thereto. The cross-sectional dimension of the hole 101 is variously changed in relation to the cross-sectional dimension of the reinforcing material 1A to be used. When the reinforcing material 1A having a substantially circular cross section is used, the inner diameter D2 of the hole 101 is usually reinforced. By increasing the outer diameter of the reinforcing portion 11 of the material 1A by 5 to 50 mm, good results can be obtained in both workability and reinforcing effect. Even when the cross-sectional shape of the reinforcing portion 11 of the reinforcing material 1A is other than a substantially circular shape, the long side and the short side of the cross-sectional shape of the hole 101 are respectively long and short sides of the cross-sectional shape of the reinforcing portion 11 of the reinforcing material 1A. What is necessary is just to enlarge as above-mentioned rather than a dimension. Of course, the hole 101 having a diameter larger than the maximum dimension of the cross-sectional shape of the reinforcing member 1A may be drilled.
[0048]
Filler 2 includes epoxy resin, concrete containing acrylic resin and resin material having good adhesion to reinforcing material 1A; polymer mortar, polymer cement mortar, cement mortar, non-shrink mortar, mortar containing expandable mortar; polymer Concrete, concrete including polymer cement concrete, cement concrete, non-shrinkable concrete, expansible concrete, and the like can be suitably used. When the expandable mortar or expandable concrete mixed with the expandable material is used, the reinforcing material 1A inserted into the hole 101 can be firmly fixed by the frictional force due to the expansion pressure of the mortar or concrete.
[0049]
In addition, in this invention, arrangement | positioning of the reinforcing material 1 to the hole 101 and filling of the filler 2 to the hole 101 are not limited to implementing in this order at all. After injecting the filler 2 into the hole 101, the reinforcing material 1 is inserted into the hole before the filler 2 is cured, so that the periphery of the reinforcing material 1 is filled with the filler 2 in the hole 101. Thereafter, the reinforcing material 1 may be fixed with the filler 2.
[0050]
As described above, the reinforcing material 1 is disposed in the hole 101 provided in the concrete wall 100, and the reinforcing material 1 is fixed with the filler 2. Thus, the shear strength of the concrete wall 100 can be increased by a very simple construction method. Improvements can be made.
[0051]
By the way, as described above, the reinforcing material 1 </ b> A that is substantially disposed in the hole 101 and extends only in the axial direction of the hole 101 and includes only the rod-like first portion (reinforcing portion) 11 is fixed by the filler 2. Thus, a certain reinforcing effect can be obtained. However, on the tensile stress acting surface of the concrete wall 100 (when a force is applied in the direction indicated by the arrow P in FIG. 1), a force is applied so that the reinforcing material 1A comes out of the hole 101, and the reinforcing effect is obtained. May decrease. Therefore, in order to improve the fixing to the concrete, the reinforcing material 1 is configured as described below.
[0052]
According to the present invention, in order to more firmly fix the reinforcing member 1, the reinforcing member 1 intersects the first portion (reinforcing portion) 11 extending in the axial direction in the hole 101 and the axial direction of the hole 101. And a second portion extending in the direction. In one embodiment of the present invention, the second portion is connected to the first portion (reinforcing portion) 11 and is outside the hole 101, the surface of the concrete wall 100, particularly at least the tensile stress acting surface of the concrete wall 100. It is arranged along.
[0053]
In particular, in the present embodiment, the reinforcing member 1 has a plurality of first portions (reinforcing portions) 11 respectively disposed in separate holes 101 provided in the concrete wall 100 as shown in FIG. The second portion is configured to be disposed along the surface of the concrete wall 100 outside the hole 101 and to have a connecting portion 12 that connects the plurality of first portions (reinforcing portions) 11 to each other.
[0054]
More specifically, such a reinforcing member 1 can be configured as a substantially U-shaped reinforcing member 1B in which two reinforcing portions 11 are connected by a connecting portion 12, as shown in FIG. Further, as shown in FIG. 5, a mountain-shaped reinforcing material 1 </ b> C in which three reinforcing portions 11 are connected by connecting portions 12, or a larger number of reinforcing portions 11 (five in the illustrated example) are connected by connecting portions 12. It can be set as the comb-shaped reinforcement 1D.
[0055]
Thus, by arranging the connecting portion 12 on at least the assumed tensile stress acting surface side of the concrete wall 100 and connecting the plurality of reinforcing portions 11, the connecting portion 12 mechanically acts on the tensile stress acting surface. The effect of the fixing portion for fixing the reinforcing material 1 can be exhibited, and the reinforcing effect of the concrete wall 100 by the reinforcing material 1 can be improved.
[0056]
In the example shown in FIGS. 4 and 5, the plurality of reinforcing portions 11 are arranged in the plurality of holes 101 arranged along the longitudinal direction of the concrete wall 101. As a result, the connecting portion 12 is oriented in the longitudinal direction of the concrete wall 100 and extends in a direction substantially orthogonal to the axial direction of the existing reinforcing bars (tensile reinforcing bars, compressive reinforcing bars) 110 in the concrete wall 100. In this case, the interval between the reinforcing portions 11 is substantially the same as the opening center interval W <b> 2 of the hole 101 in the vertical direction of the concrete wall 100. Thereby, a fixing portion having a length L2 corresponding to the length of the connecting portion 12 (here, substantially the same as the interval W2 of the reinforcing portion 11) can be provided. As described above, when the hole 101 has an angle α (> 0) with respect to the normal direction N of the concrete wall 100, the interval between the plurality of reinforcing portions 11 is the vertical distance between the holes 101 (the distance between the centers). ) And the length L2 of the connecting portion 12 is substantially the same as the opening center interval W2 of the hole 101.
[0057]
In the present embodiment, the connecting portion (fixing portion) 12 as the second portion is provided substantially perpendicular to the reinforcing portion 11 as the first portion, but the present invention is not limited to this. . The second portion only needs to be provided in a direction intersecting the first portion. For example, as described with reference to FIG. 3, the hole 101 has an angle α with respect to the normal direction N of the concrete wall 100. For example, when having (> 0), the second portion intersects the first portion at an angle other than a right angle. Preferably, the angle formed by the second portion with respect to the first portion is in the range of 90 ° ± 60 °, more preferably 90 ° ± 45 °, and still more preferably 90 °.
[0058]
Further, the length L2 of the connecting portion (fixing portion) is determined by the thickness T of the concrete wall 100, the arrangement mode of the reinforcing material 1 (hole 101), and the like. The pitch of the shear reinforcement bars is usually determined so that the number necessary to obtain the required yield strength can be secured below the wall thickness. A connecting portion having an arbitrary length that connects the reinforcing portions 11 of the reinforcing materials 1 that are typically arranged in the adjacent holes 101 in accordance with the arrangement of the reinforcing materials 1 (holes 101) determined in this manner. By providing 12, the fixing effect is dramatically improved as compared to the case where this is not provided.
[0059]
Making the orientation of the connecting portion 12 in the direction along the longitudinal direction of the concrete wall 100 improves the pulling strength of the reinforcing portion 11 and destroys the tensile side surface (first surface 100A in the illustrated example) of the concrete wall 100. It is preferable in terms of prevention. However, the present invention is not limited to this.
[0060]
Further, as shown in FIG. 6, the plurality of reinforcing portions 11 arranged in the plurality of holes 101 arranged in the vertical direction of the concrete wall 100 and the plurality of holes arranged in the horizontal direction of the concrete wall 100. You may form the reinforcement 1E which mutually connected the some reinforcement part 11 made in 101 by the vertical direction connection part 12a and the horizontal direction connection part 12b. In this case, the vertical interval and the horizontal interval of the reinforcing portion 11 are substantially the same as the intervals W2 and W1 of the holes 101 in the vertical direction and the horizontal direction of the concrete wall 100, respectively. Accordingly, fixing portions having lengths L2a and L2b respectively corresponding to the lengths of the vertical direction connecting portion 12a and the horizontal direction connecting portion 12b (here, substantially the same as W2 and W1, respectively) can be provided.
[0061]
In addition, the reinforcement part 11 and the connection part 12 may be integrally formed by welding, molding, etc. with the above-mentioned reinforcing bars and FRP bars, respectively, or may be joined by appropriate connection means. If it is an FRP streak, it can be relatively easily formed into an arbitrary shape in a state in which the matrix resin is not impregnated, or in an impregnated but uncured or semi-cured state.
[0062]
In the above description, the second portion has been described as the connecting portion 12 that connects the plurality of reinforcing portions 11, but is not limited thereto. As shown in FIG. 7, the plurality of reinforcing portions 11 are not provided, but the reinforcing portion 11 and the second portion connected to the reinforcing portion 11 and arranged along the surface of the concrete wall 100 outside the hole 101. A reinforcing member 1F having a bent portion 15 (substantially perpendicular to the reinforcing portion 11 in the illustrated example), that is, a substantially L-shaped reinforcing member 1F may be configured. In this case, the length L2 of the bent portion (fixing portion) 15 is one time the maximum dimension (thickness or diameter) of the cross-sectional shape of the reinforcing portion 11 although it is variously changed depending on the required reinforcement strength. To 100 times, more preferably 5 to 20 times. Generally, when the length L2 is 20 mm to 200 mm, a good fixing effect can be obtained. Further, the bent portion 15 as the second portion is not limited to an embodiment provided at a substantially right angle with respect to the reinforcing portion 11 as the first portion, and can be variously changed in the same manner as the connecting portion (fixing portion) 12. It is. In addition, a plurality of the bent portions 15 may be connected to one reinforcing portion 11.
[0063]
Further, the second part (the connecting part 12 and the bent part 15) is connected to the first part (reinforcing part) 11 and arranged along the surface of the concrete wall 100 outside the hole 101 and has the function of a fixing part. Is not limited to those extending in a rod shape. For example, as shown in FIG. 7, a second portion extending in a planar shape in a direction intersecting the axial direction of the hole 101 may be provided. In the example shown in the figure, the second portions (connecting portion 12 or bent portion 15) extending in a disk shape indicate the reinforcing materials 1Ba and 1Fa connected to a plurality of or a single first portion (reinforcing portion) 11. The second portion extending in a planar shape can be formed by, for example, a steel plate or FRP plate that is connected by an appropriate means such as welding or bolt fastening, or formed integrally.
[0064]
As described above, according to the present invention, it is possible to improve the shear strength of the concrete wall 100 in which the reinforcing material cannot be wound around the outer periphery by a very simple construction method. In particular, according to the present invention, a reinforcing effect against the out-of-plane shear force of the concrete wall 100 can be obtained. In addition, even when the concrete wall 100 is a problem of a decrease in the internal volume due to the increase in thickness, like a continuous wall of a box culvert, the shear strength can be improved without a significant increase in the cross-sectional dimension.
[0065]
Example 2
Next, another embodiment of the present invention will be described. Hereinafter, elements having the same or corresponding functions and configurations as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
[0066]
As the reinforcing material 1, an FRP lattice material which is a continuous fiber reinforcing material can also be used. Referring to FIG. 23, the FRP lattice material 200 is generally composed of a plurality of reinforcing bars arranged in a lattice pattern intersecting at right angles, that is, vertical reinforcing bars 201 and lateral reinforcing bars 202. The vertical reinforcing bar 201 and the horizontal reinforcing bar 202 are mainly made of glass fiber, carbon fiber, aramid fiber, or other reinforcing fibers (which may be the same as the above FRP bars) arranged in one direction, such as vinyl ester resin. It is formed by laminating a plurality of band-shaped reinforcing fibers impregnated with a matrix resin (which may be the same as the above FRP streaks). Further, the vertical reinforcing bar 201 and the horizontal reinforcing bar 202 have a bar width (w) of 3 to 20 mm and a thickness (t) of 1 to 20 mm, and an inter-lattice distance (a vertical reinforcing bar center distance, a horizontal reinforcing bar center distance). ) (W3) It is molded and cured into a lattice plate shape of 25 to 200 mm to form a sheet-like FRP lattice material 200 as a whole.
[0067]
In addition, the size and strength of the FRP lattice material 200 to be used can be variously changed according to the required reinforcing strength and the arrangement of reinforcing bars on the concrete wall 100. Generally, the vertical reinforcing bars 201 and the horizontal reinforcing bars are used. 202 each has a tensile strength of 500 N / mm ² ~ 2000N / mm ² , Tensile modulus 20kN / mm ² ~ 300kN / mm ² Are preferably used.
[0068]
An example of the FRP lattice material 200 that can be suitably used in the present invention is as follows.

[0069]
This FRP lattice material 200 can be cut out as shown in FIG. 8, for example, and used as the reinforcing material 1 according to the present invention. The reinforcing material 1G shown in FIG. 8 is substantially composed only of a portion disposed in the hole 101. More specifically, the reinforcing portion 11 arranged along the axial direction of the hole 101 and the second portion extending in a direction intersecting the axial direction of the hole 101 are arranged in the hole 101 and intersected with the reinforcing portion 11. 13 is formed. In the present embodiment, the reinforcing portion 11 is formed by a vertical reinforcing bar 201 arranged along the axial direction of the hole 101, and the protruding portion 14 is formed by a horizontal reinforcing bar 202 substantially orthogonal to the vertical reinforcing bar 201, These form a plurality of intersections 13 in the hole 101. In the example shown in the drawing, the protruding portion 14 protrudes at a predetermined protruding amount p in the direction substantially perpendicular to the axial direction of the hole 101 on both sides of the reinforcing portion 11 formed of the vertical reinforcing bars 201 at the intersection point 13. It is formed by cutting the lateral reinforcing bars 202.
[0070]
As described above, the reinforcing portion 11 has at least one intersection 13 between the vertical reinforcing bar 201 and the horizontal reinforcing bar 202 of the FRP lattice material 200, so that the filler 2 of the reinforcing material 1 is connected to the reinforcing material 1 by the intersection 13 in the hole 101. Adhesion is ensured. Thereby, the reinforcement effect by the reinforcing material 1 improves.
[0071]
The protruding amount p of the protruding portion 14 in the direction orthogonal to the axial direction of the hole 101 is preferably 1/2 to 5 times the maximum dimension (thickness or diameter) of the cross-sectional shape of the reinforcing portion 11. When the protruding amount p is less than the above range, the effect of improving the adhesion by providing the protruding portion 14 cannot be obtained. On the other hand, when the protrusion amount p exceeds the above range, the yield strength is not further improved, and the diameter of the hole 101 is increased. Therefore, more preferably, the protrusion amount p is 1/2 to 2 times the maximum dimension (thickness or diameter) of the cross-sectional shape of the reinforcing portion 11. Although various changes can be made according to dimensions such as the width (w) and thickness (t) of the FRP lattice material 200 to be used (or the diameter of the reinforcing material 1 to be used), the protrusion amount p is usually 5 mm. Good results can be obtained at ˜25 mm in terms of workability and reinforcing effect, particularly in terms of fixability of the reinforcing material 1.
[0072]
In addition, by providing the protrusions 14 on both sides of the reinforcing portion 11 as in this embodiment (protrusion amount 2p), better adhesion to the filler 2 can be exhibited. Alternatively, the reinforcing part 11 may be provided only on one side surface. Moreover, the protrusion part 14 is not limited to the aspect protruded in the direction substantially orthogonal to the reinforcement part 11. As shown in FIG.
[0073]
FIG. 9 shows another embodiment of the reinforcing material 1 formed from the FRP lattice material 200. The reinforcing member 1H shown in FIG. 9 has two reinforcing portions 11 arranged in the hole 101 and a connecting portion 12 that connects them, and is cut out so as to be substantially U-shaped as a whole. is there. The reinforcing portion 11 includes a vertical reinforcing bar 201 disposed along the axial direction of the hole 101, and the connecting portion 12 includes a horizontal reinforcing bar 202 substantially orthogonal to the vertical reinforcing bar. Further, the reinforcing portion 11 is provided with a plurality of protruding portions 14 formed by the lateral reinforcing bars 202 as a second portion extending in a direction intersecting the axial direction of the hole 101. A plurality of intersections 13 with 14 are formed. In the example shown in the drawing, the protruding portion 14 is formed by cutting the lateral reinforcing bars 202 at the intersection points 13 on both sides of the reinforcing portion 11 formed of the vertical reinforcing bars 201 so as to protrude with a predetermined protruding amount p. Yes.
[0074]
In the reinforcing member 1H shown in FIG. 9, the reinforcing portion 11 and the connecting portion 12 are each composed of the vertical reinforcing bar 201 and the horizontal reinforcing bar 202 intersecting with the FRP lattice material 200, but the present invention is not limited to this. Instead, for example, the reinforcing part 11 and the connecting part 12 can be formed by the vertical reinforcing bars 201 by bending the vertical reinforcing bars 201 into a substantially U shape.
[0075]
In FIG. 10, three reinforcing portions 11 are connected by connecting portions 12, and a plurality of protruding portions 14 are provided on both sides of each reinforcing portion 11 with protruding amounts p. Indicates. You may provide many reinforcement parts 11 further.
[0076]
Further, FIG. 11 shows a reinforcing material 1J that is formed by cutting a plurality of reinforcing portions 11 arranged in the vertical direction and the horizontal direction so as to be connected to each other by a connecting portion 12 and having a shape. In the illustrated example, by bending the vertical reinforcing bars 201, three substantially U-shaped reinforcing portions 11 made of the vertical reinforcing bars 201 are connected by three connecting portions 12 each made of the horizontal reinforcing bars 202. It is molded into. A plurality of protruding portions 14 are provided on both sides of each reinforcing portion 11 with a protruding amount p.
[0077]
The reinforcing material 1G shown in FIG. 8 can be inserted into the hole 101 provided in the concrete wall 100 in the same manner as that shown in FIG. Further, the reinforcing members 1H, 1I, and 1J shown in FIGS. 9 to 11 can be inserted into the holes 101 provided in the concrete wall 100 in the same manner as those shown in FIGS. By arranging the connecting portion 12 on the tensile stress acting surface of the concrete wall 100, a length L2 corresponding to the length of the connecting portion 12 (the length of the longitudinal connecting portion 12a and the lateral connecting portion 12b in FIG. 11). The fixing portions having the lengths L2a and L2b) corresponding to the above can be provided, and the same fixing effect as described above can be obtained.
[0078]
When the reinforcing member 1 formed from the FRP lattice material 200 is used, the hole 101 is larger by 5 to 50 mm than the width W4 that is the sum of the stripe width w and the protrusion amount p in one direction, and the FRP lattice in the other direction. By making the cross-sectional shape (rectangle, ellipse, etc.) larger by 5 to 50 mm than the thickness t of the material 200, good results can be obtained in both workability and reinforcing effect. Of course, the hole 101 having a diameter larger than the maximum dimension of the cross-sectional shape of the reinforcing member 1 disposed in the hole 101 may be drilled.
[0079]
As shown in FIG. 12, the FRP lattice material 200 does not have a plurality of reinforcing portions, but is connected to the reinforcing portion 11 and the reinforcing portion 11 and the surface of the concrete wall 100 outside the hole 101. The reinforcing member 1K having the bent portion 15 as the second portion arranged along the line, that is, the substantially L-shaped reinforcing member 1K may be configured.
[0080]
Further, as described above, since the FRP lattice material 200 can easily form the protruding portion 14 by appropriately cutting the vertical reinforcing bar 201 and the horizontal reinforcing bar 202, the reinforcing material having the protruding portion 14 is used. Convenient to form 1. However, the present invention is not limited to this, and a welded rebar or an appropriately formed FRP rebar can also be used.
[0081]
Example 3
Next, another embodiment of the present invention will be described. As described above, by arranging the connecting portion 12 on the tensile stress acting surface of the concrete wall 100, the shear reinforcement effect is improved.
[0082]
In the present embodiment, as shown in FIG. 13, the substantially U-shaped reinforcing material that is substantially the same as that described in the first embodiment from both sides of the concrete wall 100, that is, the openings at both ends of the hole 101, is used. Insert 1B and 1B ′. At this time, the reinforcing members 1B and 1B ′ are formed so that the reinforcing portions 11 of the reinforcing members 1B and 1B ′ form lap joints in the respective holes 101. Depending on the strength and diameter of the reinforcing material 1B, the type of the filler 2, or the type of concrete, an overlap length L2 is provided so that sufficient stress transmission between the reinforcing materials 1B and 1B ′ can be obtained. Although various changes can be made, a good result is usually obtained by setting the overlap length L2 to 5 to 20 times the maximum dimension (thickness or diameter) of the cross-sectional shape of the reinforcing portion 11 of the reinforcing material 1. It is done.
[0083]
By providing the lap joints of the reinforcing members 1B and 1B ′ in this way to form a closed system, the reinforcing effect against the positive and negative alternating loads in which forces (arrows P and P ′ in the figure) are applied to the concrete wall 100 from both sides. Can be improved.
[0084]
In addition, although the above demonstrated the case where the substantially U-shaped reinforcement 1B which consists of a reinforcing bar and a FRP reinforcement was used, the thing of the other shape demonstrated with reference to FIG. 5, FIG. 6, or FIGS. It is obvious that one formed from the FRP lattice material described with reference to FIG. Further, the substantially L-shaped reinforcing material 1F (or reinforcing material 1K) (FIGS. 7 and 12) as described above, or the reinforcing material 1Ba or 1Fa (FIG. 7) having the planar second portion 12 or 15 is used. It is good also as a structure which inserts from the both-sides opening part of the hole 101, and provides a coupling. FIG. 14 shows an example using substantially L-shaped reinforcing materials 1F and 1F ′.
[0085]
Example 4
Next, another embodiment of the present invention will be described. For example, in the bottom plate and side wall of an underground structure, the structure is embedded in the ground, and there are cases where work can be performed only from one surface inside the structure. In such a case, even if a tensile stress acts on the concrete surface on the ground side, it is difficult or impossible to insert the reinforcing material 1 from the ground side. Therefore, for example, the connecting portion 12 of the reinforcing material 1 </ b> B having a fixing effect as shown in FIG. 4 cannot be disposed on the tensile stress acting surface of the concrete wall 100.
[0086]
Referring to FIG. 15, here, one surface (first surface) 100A of the concrete wall 100, which is a continuous wall of a box culvert or the like, faces the inner space of the box culvert, but the opposite side surface (second surface). ) 100B faces the ground G. In this case, the work can be performed only from the first surface 100A side, but when there is a force in the direction of the arrow P in the drawing, tensile stress acts on the lower side of the second surface 100B side.
[0087]
Therefore, in this embodiment, the reinforcing member 1L is connected to the reinforcing portion 11 as a reinforcing portion 11 extending in the axial direction in the hole 101 and a second portion extending in a direction intersecting the axial direction of the hole 101. The bent portion 15 is disposed outside the hole 101 along at least the tensile stress acting surface. In the present embodiment, the reinforcing portion 11 is formed so as to have bent portions 15 extending at substantially right angles to the reinforcing portion 11 at both ends in the axial direction. Here, the interval W5 between the two bent portions 15 and 15 is substantially the same as the thickness T of the concrete wall 100, and is substantially the same as the length L1 of the reinforcing portion 11 disposed in the hole 101. The bent portion 15 is arranged on the concrete wall, particularly on the surface acting on the tensile stress, and thereby exhibits the effect of a fixing portion for fixing the reinforcing material 1L to the concrete wall 100.
[0088]
The length L2 of the bent portion (fixing portion) 15 is the maximum dimension (thickness or diameter) of the cross-sectional shape of the reinforcing portion 11 as described above. 1 to 100 times, more preferably 5 to 20 times. In general, good results can be obtained by setting the length L2 to 20 mm to 200 mm.
[0089]
In this case, the hole 101 penetrates the concrete wall 100 and drills in a substantially normal direction of the concrete wall 100. However, when the hole 101 has a substantially circular cross section, the inner diameter D4 is equal to or longer than the length L2 of the bent portion 15. In general, the inner diameter D4 is larger than the length L2 of the bent portion 15 by 5 to 50 mm, and good results are obtained in both workability and reinforcing effect.
[0090]
In addition, in order to arrange | position the bending part 15 of the reinforcing material 1L along the 2nd surface 100B so that it may mention later, it can perforate to the ground G previously beforehand.
[0091]
As shown in FIG. 15, the reinforcing material 1L is inserted into the hole 101 from the first surface 100A side, and when the bent portion 15 passes through the opening on the second surface 100B side of the hole 101, the reinforcing material 1L is inserted into the outer periphery of the hole 101. It moves below in the direction, that is, the direction along the second surface 100B of the concrete wall 100, so that the bent portion 15 is disposed on the second surface 100B. Thereafter, the hole 101 is filled with the filler 2 to fix and fix the reinforcing material 1L.
[0092]
Referring to FIG. 16, when an obstacle such as the ground exists on the side of the tensile stress acting surface of the concrete wall 100, another method of arranging the bent portion 15 of the reinforcing material 1L on the surface is shown. Here, the cross-sectional shape of the hole 101 provided in the concrete wall 100 is a rectangle or an ellipse (a rectangle in the illustrated example). The length L4 of the long side of the cross section of the hole 101 is equal to or longer than the length L2 of the bent portion 15, and the length L4 is usually larger than the length L2 of the bent portion 15 by 5 to 50 mm. The width D5 of the short side of the cross section of the hole 101 is set to be equal to or greater than the maximum dimension (thickness or diameter) D1 of the cross-sectional shape of the reinforcing material 1L. Usually, the width D5 is greater than the thickness or diameter D1 of the reinforcing material 1L. Increase by 5-50 mm. As a result, good results can be obtained in both workability and reinforcing effect.
[0093]
As shown in FIG. 16, when the reinforcing member 1L is inserted into the hole 101 from the first surface 100A side and the bent portion 15 passes through the opening on the second surface 100B side of the hole 101, the bent portion 15 becomes the second surface 100B. The reinforcing member 1L is rotated around the axial direction of the hole 101 so as to come up. Thereafter, the filler 2 is injected into the hole 101 to fix and fix the reinforcing material 1L.
[0094]
In this way, even when an obstacle such as the ground exists on the tensile stress acting surface side of the concrete wall 100, the reinforcing member is provided by arranging the bent portion 15, that is, the fixing portion having a fixing effect on the surface. The 1 L reinforcing effect can be improved.
[0095]
Here, when the bent portions 15 are provided at both ends in the axial direction of the reinforcing portion 11 of the reinforcing member 1L, the reinforcing member 1L is fixed and fixed so that the bent portion 15 straddles the existing reinforcing bars in the concrete wall 100. Then, by arranging the reinforcing material 1L so that the existing reinforcing bars in the concrete wall 100 exist between both the bent portions 15, the pulling-out strength of the reinforcing material is improved, and thus the reinforcing effect can be further improved. .
[0096]
In the mode shown in FIG. 16, the long side direction of the cross section of the hole 101 is not limited to the horizontal as shown in the figure, and may be any other angle.
[0097]
The reinforcing material 1L of the present embodiment may be formed of any of the above-described reinforcing bars, rod-shaped reinforcing bars such as FRP bars, and FRP lattice materials. Further, using the substantially L-shaped reinforcing material 1F or 1K as described above (FIGS. 7 and 12), that is, the reinforcing material 1 in which the bending portion 15 is provided on one end side of the reinforcing portion 11, the bending is performed. You may insert in the hole 101 from the part 15 side.
[0098]
Example 5
Next, another embodiment of the present invention will be described.
[0099]
As described in the above embodiment, the shear strength of the concrete wall 100 can be increased by providing the hole 101 in the concrete wall 100 and fixing the reinforcing material 1 disposed in the hole with the filler 2.
[0100]
In this embodiment, a method for fixing the reinforcing material 1 more firmly will be described. Here, for the sake of simplicity, a description will be given of a case where the end portion of the rod-shaped reinforcing material 1A substantially consisting only of the reinforcing portion 11 disposed in the hole 101 as shown in FIG. 1 is fixed. The fixing method to be described is similarly applicable to the reinforcing material 1 according to the present invention described above.
[0101]
As shown in FIG. 17, the end of the hole 101 into which the reinforcing material 1 is inserted has a shape that is widened from the center in the axial direction of the hole 101 toward the surface side of the concrete wall 100. Although not limited to this, when the hole 101 has a substantially circular cross section, the hole 101 has a depth from the small diameter part 101A to the large diameter opening part 101B larger by 10% to 100% as described above. It is perforated so as to have a widened portion 101C whose length L5 is 20 to 200 mm and whose diameter gradually increases.
[0102]
Thereby, for example, when a force is applied to the first surface 100A as indicated by an arrow P in the drawing and a force for pulling out the reinforcing member 1A in the hole 101 toward the first surface 100A is applied, the second surface 100B of the hole 101 is applied. At the end portion on the side, the filler 2 filled in the widened portion 101C can firmly fix the reinforcing material 1 to the concrete wall 100 by the wedge effect. In order to make the wedge action more effective, expansive mortar and expansive concrete can be suitably used as the filler 2.
[0103]
As shown in the figure, by providing such a widened portion 101C at both ends in the axial direction of the hole 101, even if tensile stress acts on either the first surface 100A or the second surface 100B of the concrete wall 100, The reinforcing material 1 can be firmly fixed. However, the present invention is not limited to this. For example, a case in which a connecting portion (second portion) 12 acting as a fixing portion is provided on one surface side of the concrete wall 100 as in the reinforcing material 1B shown in FIG. Then, the reinforcing effect for positive and negative alternating loads can be improved by widening the opening of the hole 101 on the other surface side as described above.
[0104]
Further, the end portion of the reinforcing member 1 can be fixed by a fixing tool. For example, as shown in FIG. 18, the end portion of the reinforcing member 1 </ b> A can be fixed by a wedge-shaped fixing tool 40. More specifically, for example, the wedge 41 of the wedge fixing device 40 is inserted in the insertion direction of the reinforcing member 1 in the hole 101, and the wedge 41 is disposed in the widened portion 101C of the hole 101 similar to the above (FIG. 18A). Next, the reinforcing material 1 is inserted into the hole 101 (FIG. 18B). Further, the reinforcing material 1 is inserted through the wedge 41 arranged in the widened portion 101C (FIG. 18C), and the reinforcing material 1 is arranged at a predetermined position in the hole 101 (FIG. 18D).
[0105]
Thereby, the reinforcing member 1 is firmly fixed by the wedge action of the wedge fixing tool 40 against the force of pulling out the reinforcing member 1 in the direction of the arrow in FIG.
[0106]
Further, as shown in FIG. 18 (d), a locking portion 42 that engages the surface of the reinforcing material 1 is provided on the surface of the wedge 41 so as to prevent the reinforcing material 1 from moving in the direction of the arrow in the figure. Thus, the fixing effect of the wedge 41 can be improved. In this case, the locking portion 42 of the wedge 41 may be engaged with a protrusion provided on the surface of the reinforcing member 1 if the reinforcing member 1 has a deformed steel or a deformed steel surface. The receiving portion 16 that engages with the locking portion of the wedge 41 may be processed on the surface of the material 1 corresponding to the wedge fixing tool 40.
[0107]
Even when the widened portion 101C is not provided in the hole 101, the wedge fixing tool 40 as described above can be used.
[0108]
In addition, for example, the end of the reinforcing member 1 opposite to the side on which the wedge fixing tool 40 is provided is further provided with a general fixing plate 51 and a nut 52 as shown in FIG. It can be fixed by a fixing tool. In other words, the fixing plate 51 is disposed on the opening of the hole 101, and fixing is performed by screwing the nut 52 onto the screw processed on the surface of the reinforcing member 1 extending through the opening of the fixing plate 51.
[0109]
As described above, the reinforcing material 1 can be fixed more firmly by using the fixing tool (fixing means) in addition to the fixing by the filler 2.
[0110]
Example 6
Next, another embodiment of the present invention will be described. The FRP streaks described above were already impregnated with matrix resin and hardened before being placed in the hole 101. On the other hand, in this embodiment, the FRP line is hardened in the hole 101.
[0111]
Further description will be made with reference to FIG. 20. First, a flexible reinforcing fiber bundle 20 in which a predetermined number of reinforcing fibers (which may be the same as the above FPR streaks) are bundled is converted into a matrix resin (the above FRP). It may be the same as the streak.) Is inserted into the hole 101 of the concrete wall 101 before impregnation, and then the matrix resin 21 is injected into the hole 101 to impregnate the reinforcing fiber bundle, and is cured and cured. FRP bars (reinforcing material) 1M are formed. Thereafter, the filler 2 is filled into the hole 101 and the reinforcing material 1M made into an FRP line is fixed in the hole 101.
[0112]
The reinforcing fiber bundle 20 is not limited, but may be one that is focused in the same manner as that constituting the FRP streaks described in the first embodiment.
[0113]
Alternatively, the following can be used as the reinforcing fiber bundle 20. As shown in FIG. 22, a reinforcing fiber bundle f composed of a large number of reinforcing fibers f. ₀ The reinforcing fiber bundle 20 made of can be disposed in the central hole b1 of the flexible tubular covering member b disposed so as to surround the reinforcing fiber bundle 20. The resin can be injected between the tubular covering member b and the reinforcing fiber bundle 20 by, for example, maintaining a sufficient gap. The reinforcing fiber bundle 20 is generally formed by arranging reinforcing fibers f in a parallel state. That is, it is produced by bundling a plurality of strands S that are produced by twisting a predetermined number of reinforcing fibers f in parallel or loosely and twisting them in parallel or loosely. Alternatively, the reinforcing fiber bundle f focused as shown in FIG. ₀ And outer layer member f ₁ The reinforcing fiber bundle 20 may be disposed in the flexible tubular covering member b.
[0114]
The flexible tubular covering member b can be of various materials and sizes depending on the application. Generally, the inner diameter of the center hole b1 is 2 to 100 mm, the wall thickness is 0.01 mm to 50 mm, and the metal is made of metal. However, it is preferable to use a resin material. Preferable resin materials include polyethylene, polypropylene, nylon, vinyl chloride, rubber resin, and the like. Further, the tubular covering member b can be provided with an uneven shape on the outer surface in order to increase the adhesive force with the filler 2. The concavo-convex shape can be provided by forming annular undulations (or protrusions) in the shape of a knot at predetermined intervals, or by forming undulations (or protrusions) in a spiral shape. The reinforcing fiber bundle 20 disposed in the tubular covering member b is impregnated with resin by injecting a matrix resin into the tubular covering member b after being disposed in the hole 101 of the concrete wall 100 (such a resin). The method of injecting the reinforcing material and the resin is described in detail in JP-A No. 11-70596 relating to reinforcing fiber reinforcing bars proposed by the present inventors.
[0115]
Further, instead of the reinforcing fiber bundle 20 not impregnated with the matrix resin as described above, a so-called prepreg reinforcing fiber bundle 30 that has been impregnated with a matrix resin in advance but in an uncured or semi-cured state is formed in the hole 101. After the insertion, the FRP bars (reinforcing material) 1M disposed in the hole 101 may be formed by curing in the hole 101.
[0116]
When the reinforcing fiber bundle 30 in the prepreg state is formed, the reinforcing fiber bundle 30 is not limited, but may be bundled in the same manner as that constituting the FRP streak. In this case, the matrix resin can be impregnated by immersing a reinforcing fiber bundle not impregnated with resin in a resin tank containing the resin.
[0117]
Alternatively, the reinforcing fiber bundle f formed by a large number of reinforcing fibers f in the tubular covering member b as described above. ₀ The prepreg-shaped reinforcing fiber bundle 30 may be configured by arranging a matrix resin in advance in the tubular covering member b before being disposed in the hole 101 of the concrete wall 100. The reinforcing fiber bundle f0 is impregnated to be in a prepreg state. Alternatively, a reinforcing fiber bundle f consisting of a large number of reinforcing fibers f in advance. ₀ A prepreg disposed in the flexible tubular covering member b by impregnating the resin with a resin and winding a flexible covering material on the outside or forming a covering layer by injection molding or the like. A reinforcing fiber bundle 30 can be obtained.
[0118]
By the way, the resin impregnated in the reinforcing fiber bundles 20 and 30 is cured by being left standing, but the curing can be promoted by positively heating by a heating means such as a heater.
[0119]
For example, the reinforcing fiber bundles 20 and 30 are made of conductive fibers such as carbon fibers and metal wires (metal fibers) (all may be conductive fibers) or have conductivity. It is possible to mix and configure the fibers, and to energize and generate heat to heat and cure the matrix resin. Thereby, the hardening time of resin can be shortened. For example, if the reinforcing fibers f constituting the reinforcing fiber bundles 20 and 30 are conductive fibers such as carbon fibers, the curing time is shortened by energizing them to generate heat and heat curing the resin. It becomes possible. In addition, a heater wire as a heating member is preferably arranged at a substantially central position of the reinforcing fiber bundles 20 and 30, and the resin can be heated and cured by energizing the heater wire to generate heat. As the heater wire, for example, a nichrome wire, a tungsten wire, a nickel wire or the like can be used, and a flexible wire having a wire diameter of 0.1 to 20 mm is preferable.
[0120]
Since the reinforcing fiber bundles 20 and 30 as described above have flexibility, they can be easily formed into arbitrary shapes. For example, as shown in FIG. 21, it can insert in the two holes 101 as a substantially U shape, and can form the reinforcement part 11 and the connection part 12 of the reinforcing material 1M very simply.
[0121]
Alternatively, the flexible reinforcing fiber bundles 20 and 30 having flexibility as described above can be continuously arranged in a plurality of holes 101 from one end to the other end as shown in FIG. In the illustrated example, first, the reinforcing fiber bundles 20 and 30 inserted into the hole 101a from the one surface (first surface) 100A side of the concrete wall 100 are next on the opposite surface (second surface) 100B side. Is inserted into the hole 101b. Further, after being inserted into the next hole 101c on the first surface 100A side, it is inserted into the next hole 101d on the second surface 100B side and reaches the opening on the first surface 100A side. Thereby, the connection part 12 of the reinforcing material 1M can be easily formed on both the first surface 100A and the second surface 100B of the concrete wall 100.
[0122]
Of course, the reinforcing fiber bundles 20 and 30 can form the substantially L-shaped reinforcing material M as shown in FIG.
[0123]
Here, the volume of the reinforcing fiber bundle is V _F The amount (volume) of the resin impregnated in the reinforcing fiber bundle is V _R , V _F + V _R = V _T Then, the resin filling rate (%), that is, (V _R ÷ V _T ) × 100 is preferably selected to be 5 to 90%. When the resin filling rate is less than 5%, there is a problem that stress cannot be transmitted between the reinforcing fiber and the reinforcing fiber, resulting in a decrease in the overall tensile strength. Not only does the amount become relatively small and the overall tensile strength does not increase, but there also arises a problem that the resin cannot be physically impregnated. Therefore, the resin filling rate is preferably 30 to 80%.
[0124]
The reinforcing fiber bundle 20 that is not impregnated with the resin is conveyed to the construction site as a roll of an appropriate unit, for example, and can be cut corresponding to any hole interval of the holes 101 provided in the concrete wall 100 there. Moreover, the reinforcing fiber bundle 30 in a prepreg state can be produced by impregnating the reinforcing fiber with a resin at a construction site and used. Alternatively, the prepreg reinforcing fiber bundle 30 preliminarily impregnated with the matrix resin may be transported to the construction site as, for example, an appropriate unit roll.
[0125]
As described above, the reinforcing reinforcing fiber bundles 20 and 30 having flexibility as in the present embodiment are made effective after being arranged in the hole 101, so that the effect of reinforcing the concrete wall 100 can be obtained in the same manner as in the above embodiments. In addition, since the reinforcing material 1 can be easily formed into an arbitrary shape by cutting and bending the reinforcing material 1 at the construction site, workability is good.
[0126]
Example 7
Next, still another embodiment of the present invention will be described. The present embodiment is a method combined with a known concrete thickening method when reinforcement is required for bending and in-plane shear force in addition to out-of-plane shear strength.
[0127]
As described above, according to the methods described in the above embodiments, the out-of-plane shear strength of the concrete member can be mainly improved.
[0128]
On the other hand, conventionally, an FRP lattice material 200 as shown in FIG. 23 or a lattice material which is a reinforcing bar formed into a lattice shape by welding (hereinafter, the FRP lattice material 200 is used here) is used as a concrete surface. It is attached to the concrete structure by fixing it with anchor bolts, then sprayed with cement mortar, etc., coated with a trowel, coated, thickened the concrete surface, or placed a formwork, and poured ready-mixed concrete There is a method of reinforcing a concrete structure by integrating the FPR lattice material and the concrete structure. Such a method can mainly improve the bending strength and in-plane shear strength of the concrete member.
[0129]
Therefore, in this embodiment, as shown in FIG. 24, holes 101 are provided at predetermined positions of the concrete wall 100 as the reinforced concrete member, and the FRP lattice material 200 is disposed on the surface of the concrete wall 100. Then, the FRP lattice material 200 (in the example shown in the drawing) is provided by the second portion of the reinforcing material 1 arranged along the surface of the concrete wall 100 outside the hole 101, for example, the connecting portion 12 of the reinforcing material 1B shown in FIG. The reinforcing material 1B is inserted into the hole 101 of the concrete wall 100 so as to fix the two lateral reinforcing bars 202). Then, the reinforcing material 1B is fixed by filling the hole 101 with the filler 2. Of course, as described above, the filler material 2 may be filled in the hole 101 before the reinforcing material 1 is inserted.
[0130]
As a result, the FRP lattice material 200 can be fixed with the reinforcing material 1 without using anchor bolts that are conventionally used and not related to the reinforcing effect of the concrete member or by reducing the amount of use.
[0131]
Thereafter, thickening of cement mortar, polymer mortar, mortar containing polymer cement mortar, or concrete including cement concrete, polymer concrete, polymer cement concrete on the surface of concrete wall 100 provided with FRP lattice material 200 and reinforcing material 1B The concrete wall 100 is thickened by providing a known method such as spraying the material 300 and applying a trowel.
[0132]
As the reinforcing material 1, in addition to the reinforcing material 1 having the connecting portion 12, any material that has a second portion arranged in the surface direction of the concrete wall 100 so as to fix the FRP lattice material 200 can be used. You can also.
[0133]
Note that the FRP lattice material 200 can also be provided on the opposite side of the concrete wall 100. In this case, the reinforcing material 1B may be inserted and fixed in the same manner as described above from the front and back surfaces of the concrete wall 100 at different positions in the horizontal direction of the concrete wall 100. For example, as shown in FIGS. What has a joint in 101, or what has the bending part 15 in the both ends of the reinforcement part 11 as shown in FIG. 15, FIG. 16 can be used.
[0134]
As described above, according to the present embodiment, by using the reinforcing material 1 in combination with the concrete thickening method, in addition to the out-of-plane shear strength of the concrete wall 100, the bending strength and the in-plane shear strength can be improved. Can do.
[0135]
Experimental example 1
In order to verify the effect of the reinforcing method of the present invention, the RC simple beam specimen was seen as a concrete wall member, and a two-point support two-point static loading test was conducted.
[0136]
Referring to FIG. 25, the dimensions of the beam specimen 500 are a width (W0) of 300 mm, a height (H0) of 460 mm, and a length (L0) of 2700 mm, and a tensile rebar 501, a compression rebar 502, a stirrup ( Only the fulcrum position) has a reinforcing bar structure 503, the distance between fulcrums (Ls) is 2100 mm, and the distance between loads (Lp) is 300 mm. Concrete uses early-strength Portland cement and has a target compressive compressive strength of 30 N / mm. ² As laid.
[0137]
In this specimen 500, a hole 101 having a diameter of 30 mm was penetrated from the upper surface 500A using a drill (core cutter) 14 days after the concrete was cast. The hole 101 was provided along a substantially normal direction of the specimen 500 that is substantially perpendicular to the longitudinal axis direction (main muscle axis direction) of the specimen 500, that is, substantially perpendicular to the surface. Further, in the longitudinal direction of the specimen 500, there are five holes 101 at a hole center distance (Lr1) of 175 mm between one fulcrum and one loading point, and between the other fulcrum and the other loading point. The center distance (Lr2) was 140 mm, and 6 rows were provided, and in the width (W0) direction of the specimen 500, two rows were provided at intervals (Wr) of 100 mm, for a total of 22 locations. The holes 101 provided in two rows in the width W0 direction of the specimen 500 were arranged 100 mm inside from the surface. Then, the reinforcing material 1 formed from the FRP lattice material shown in FIG. 9 was used, and the two reinforcing portions 11 of the reinforcing material 1 were inserted into two holes provided in the width W0 direction of the specimen 500, respectively. The hole 101 into which the reinforcing material 1 was inserted was filled with the filler 2 and cured for 7 days. One side of the shear span in which the hole 101 was provided with a hole center distance (Lr1) of 175 mm was taken as a measurement span.
[0138]
In the experiment, the reinforcing material 1 was inserted from the upper surface 500A of the specimen 500 (Specimen No. 3), from the lower surface 500B (Specimen No. 4), or from both the upper and lower surfaces 500A and 500B (Specimen No. 2). The test was performed for each of the specimen and an unreinforced specimen (sample No. 1) where the reinforcing material 1 was not provided. As the reinforcing material 1 and the filler 2, the following were used.
[0139]

The measurement items were main reinforcing bar strain, crack occurrence, load resistance and specimen variation.
[0140]
[Table 1]

[0141]
Table 1 shows the maximum load and failure mode results for each specimen. The unreinforced specimen (Specimen No. 1) was subjected to shear compression fracture, and the three specimens (Specimen Nos. 2 to 4) that were shear reinforced with the reinforcing material 1 were bent and fractured. In specimen numbers 2 to 4, the maximum load was almost the same (500 kN). In all the specimens, an initial bending crack occurred at about 100 kN, and an oblique crack occurred at around 250 kN. Thus, the shear reinforcement effect of the reinforcing material 1 was confirmed by the bending failure caused by the reinforcing material 1 in the unreinforced specimen that sheared and destroyed.
[0142]
FIG. 26 shows a load variation curve. In specimen Nos. 2 to 4, unloading was performed when a bending compression fracture was visible in the equal bending section. From FIG. 26, since the maximum load is improved by 35% or more in any of the specimen numbers 2 to 4 with respect to the unreinforced specimen (specimen number 1), the shear failure occurs. It was confirmed that the proof stress was improved by 35% or more regardless of the reinforcement method for specimen numbers 2 to 4.
[0143]
In this way, by inserting the reinforcing material 1 into the hole 101 and not fixing with a fixing tool such as a bolt or nut, but fixing with a resin, the shear strength can be increased and the failure mode can be shifted from shear failure to bending failure. It became clear that it was possible.
[0144]
FIG. 27 shows the strain shear force between the reinforcing material 1 and the concrete calculated from the measured strain of the reinforcing material 1. From this result, in any specimen, the concrete bears the shearing force up to a load of 130 kN where the oblique cracking occurred (loading load 260 kN), and the shearing strength Vs of the reinforcing material 1 gradually increases after the occurrence of the oblique cracking. It can be seen that the reinforcing material 1 functions as a shear reinforcement. The ultimate shear stress of the reinforcing material 1 at the end of the test piece No. 2 (from the top and bottom surfaces) with the largest cross-sectional area of the reinforcing material 1 was the largest, followed by the specimen No. 4 (from the bottom surface), and the specimen No. 3 ( (From the top) is the least.
[0145]
From FIG. 27, it can be seen that the effect of the reinforcing material 1 as a shear reinforcing material increases in the order of the specimen number 3 (from the upper surface), the specimen number 4 (from the lower surface), and the specimen number 2 (from the upper and lower surfaces). . That is, it can be seen that the lower surface 500B of the specimen 500 is a tensile stress acting surface, and it is more preferable to arrange the connecting portion (fixing portion) 12 of the reinforcing material 1 along the tensile stress acting surface.
[0146]
On the other hand, since the specimen No. 3 in which the reinforcing material 1 is inserted from the upper surface 500A side also shows a shear reinforcement effect, for example, it does not have the connecting portion 2 along the concrete wall surface, and is substantially disposed in the hole 101. It can be seen that the effect of the present invention can also be obtained by using the reinforcing material 1 consisting of only the portion.
[0147]
More specifically, in specimen No. 4 (from the lower surface), the tensile surface of the beam is fixed by mechanical fixing by the connecting portion (lateral reinforcing bar) 12 and adhesion by resin, and the hole 101 is formed on the upper side of the beam which is a compression region. It is fixed only by adhesion with resin. On the other hand, in specimen No. 3 (from the upper surface), only adhesion by the resin is fixed on the lower side of the beam serving as the tensile region. In this case, a sufficient fixing strength can be obtained even by resin fixing due to the restraining effect in the compression region, but there is no restraining effect in the tension region, and conversely, stress acts on the concrete in the direction in which the concrete and the resin peel. From the above results, it is possible to more reliably fix the reinforcing material 1 by providing mechanical fixing by the connecting portion (that is, the second portion arranged along the surface of the concrete wall) in the tensile region, and further It was confirmed that a good reinforcing effect can be obtained.
[0148]
【The invention's effect】
As described above, in the method for reinforcing a concrete structure according to the present invention, the reinforced concrete member is provided with a hole whose axial direction is a predetermined angle with respect to the surface of the reinforced concrete member; the hole extends in the axial direction of the hole. At least a first portion of a reinforcing member comprising a first portion and a second portion extending in a direction intersecting the axial direction of the hole is disposed in the hole; and the reinforcing material is fixed by filling the hole with a filler. Because it is configured to include
(1) It is possible to improve the shear strength of a concrete structure, in particular, a surface member such as a wall or a floor where a reinforcing material cannot be wound around the outer periphery.
(2) The shear strength of the concrete structure, in particular, the surface member can be improved, and the construction is not accompanied by a significant increase in cross-sectional dimensions unlike the concrete thickening method.
Such effects can be obtained.
[0149]
The method for reinforcing a concrete structure according to the present invention is further arranged in a fiber-reinforced plastic lattice material or a lattice shape in which a plurality of continuous fibers intersect each other along the surface of the reinforced concrete member. A grid member made of reinforcing steel bars; when the reinforcing material is placed in the hole, the grid material is fixed to the surface of the reinforced concrete member at the second portion of the reinforcing material; By including thickening the surface of the reinforced concrete member fixed with mortar or concrete, (3) it can be used with a concrete thickening method that can mainly improve bending strength and in-plane shear strength, The out-of-plane shear strength of the concrete member can be easily improved.
Such effects can also be achieved.
[Brief description of the drawings]
FIG. 1 is a perspective view of a concrete wall for explaining the principle of a concrete structure reinforcing method according to the present invention.
FIG. 2 is a perspective view showing an embodiment of a reinforcing material.
FIG. 3 is an explanatory diagram for explaining a drilling direction of a concrete wall.
FIG. 4 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 5 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 6 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 7 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 8 is a perspective view showing another embodiment of a reinforcing material.
FIG. 9 is a perspective view showing another embodiment of a reinforcing material.
FIG. 10 is a perspective view showing another embodiment of a reinforcing material.
FIG. 11 is a perspective view showing another embodiment of a reinforcing material.
FIG. 12 is a perspective view showing another embodiment of a reinforcing material.
FIG. 13 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 14 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 15 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 16 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 17 is a cross-sectional view showing an embodiment of a reinforcing material fixing method applicable to the concrete structure reinforcing method according to the present invention.
FIG. 18 is a cross-sectional view of an essential part showing another embodiment of a fixing method of a reinforcing material that can be applied to the reinforcing method of a concrete structure according to the present invention.
FIG. 19 is a cross-sectional view showing another embodiment of a fixing method of a reinforcing material that can be applied to the reinforcing method of a concrete structure according to the present invention.
FIG. 20 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 21 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 22 is a perspective view showing still another embodiment of the reinforcing material.
FIG. 23 is a perspective view for explaining an FRP lattice material forming a reinforcing material.
FIG. 24 is a perspective view of a concrete wall for explaining another embodiment of the method for reinforcing a concrete structure according to the present invention.
FIG. 25 is an explanatory diagram of a specimen used to show the effect of the present invention.
FIG. 26 is a graph of a load variation curve showing the effect of the present invention.
FIG. 27 is a graph of the applied shear force showing the effect of the present invention.
[Explanation of symbols]
1 (1A-1M) Reinforcement material
2 Filler
11 Reinforcement part (first part)
12 Connecting part (second part)
15 Bent part (second part)
20 Reinforcing fiber bundle
30 Prepreg-like reinforcing fiber bundle
100 concrete wall (reinforced concrete member)
101 holes

Claims (30)

In the reinforced concrete member, a hole whose axial direction is at a predetermined angle with respect to the surface of the reinforced concrete member is provided,
Disposing at least the first part of the reinforcing material in the hole, the first part extending in the axial direction of the hole and the second part extending in a direction intersecting the axial direction of the hole;
Filling the hole with a filler to fix the reinforcement;
A method for reinforcing a concrete structure, comprising: The method for reinforcing a concrete structure according to claim 1, wherein the hole is provided so that an axial direction of the hole is within 60 degrees with respect to a normal direction of the reinforced concrete member. 3. The concrete according to claim 1, further comprising a fixing portion connected to the first portion as the second portion and disposed along the surface of the reinforced concrete member outside the hole. A method of reinforcing structures. When providing the hole, the hole is provided through the reinforced concrete member,
When the reinforcing material is disposed in the hole, the reinforcing material is inserted into the hole from the end where the fixing portion is provided, and then the reinforcing material is moved in a direction along the surface of the concrete member to be reinforced. Or rotate around the axial direction of the hole, and arrange the fixing portion along the surface of the reinforced concrete member,
The method for reinforcing a concrete structure according to claim 3. The method for reinforcing a concrete structure according to claim 4, wherein the fixing portion is provided at both ends of the reinforcing material. The reinforcing material is disposed in the hole of the reinforced concrete member such that existing reinforcing bars in the reinforced concrete member exist between the fixing portions provided at both ends of the reinforcing material. The method for reinforcing a concrete structure according to claim 5. The reinforcing member has a plurality of the first parts respectively disposed in the separate holes provided in the reinforced concrete member, and the fixing unit connects the plurality of first parts to each other. 4. The method for reinforcing a concrete structure according to claim 3, further comprising a connecting portion disposed along the surface of the reinforced concrete member outside the hole. The reinforcing member has a substantially U shape in which two of the first portions are connected by the connecting portion, a substantially mountain shape in which the three first portions are connected by the connecting portion, or four or more of the first portions. The method for reinforcing a concrete structure according to claim 7, wherein the shape is a substantially comb shape connected by the connecting portion. When providing the hole, the hole is provided through the reinforced concrete member,
When arranging the reinforcing material in the hole, the reinforcing material is inserted from both side openings of the hole, and arranged so that at least a part of both reinforcing materials overlaps in the hole,
The method for reinforcing a concrete structure according to claim 3, 7 or 8, wherein when the reinforcing material is fixed by the filler, a lap joint of the reinforcing material inserted from both side openings of the hole is formed. 10. The projection according to claim 1, wherein the second portion includes a protrusion that is disposed in the hole and forms an intersection with the first portion in the hole. A method of reinforcing concrete structures. The method for reinforcing a concrete structure according to claim 11, wherein the reinforcing material includes a plurality of the protrusions. The protrusion amount of the protrusion from the first portion in the direction orthogonal to the axial direction of the hole is 1/2 to the maximum dimension of the cross-sectional shape of the first portion in the direction orthogonal to the axial direction of the hole. The method for reinforcing a concrete structure according to claim 10 or 11, wherein the method is five times. The method for reinforcing a concrete structure according to any one of claims 1 to 12, wherein the reinforcing material is formed of a metal or fiber reinforced plastic rod. The reinforcement of a concrete structure according to any one of claims 1 to 12, wherein the reinforcing material is formed of a fiber reinforced plastic lattice material in which a plurality of continuous fibers intersect each other to form intersections. Method. When the hole is provided, the end of the hole has a shape in which the diameter is increased from the center of the reinforced concrete member toward the surface in the axial direction of the hole. The method for reinforcing a concrete structure according to any one of the items. The method for reinforcing a concrete structure according to any one of claims 1 to 15, further comprising fixing the reinforcing material with a fixing tool at at least one end of the hole. 17. The method of reinforcing a concrete structure according to claim 16, wherein the fixing tool is a wedge-type fixing tool that is inserted into an end portion of the hole to perform a wedge action. The method for reinforcing a concrete structure according to claim 17, wherein the wedge fixing tool has a locking portion that engages with the reinforcing material. When the reinforcing material is disposed in the hole, the reinforcing fiber bundle having flexibility is inserted into the hole, and then the reinforcing fiber bundle is impregnated with resin in the hole and cured to be made of fiber reinforced plastic. The method for reinforcing a concrete structure according to any one of claims 1 to 3, wherein the reinforcing material is formed. When the reinforcing material is disposed in the hole, the hole is formed after the flexible reinforcing fiber bundle that has been impregnated with the resin but is in an uncured or semi-cured state is inserted into the hole. The method for reinforcing a concrete structure according to any one of claims 1 to 3, wherein the reinforcing material made of fiber-reinforced plastic is formed by curing the resin. The reinforcing fiber bundle is composed of conductive fibers or mixed with conductive fibers, and when the resin is cured, the conductive fibers are energized to generate heat, The method for reinforcing a concrete structure according to claim 19 or 20, wherein the resin is cured. When the reinforcing material is arranged in the hole, the reinforcing fiber bundle is arranged in two holes provided in the concrete member to be reinforced in a substantially U shape, or is continuous with three or more holes. The method for reinforcing a concrete structure according to claim 19, 20 or 21, wherein the concrete structure is arranged. The filler is made of resin; cement mortar, polymer cement mortar, polymer mortar, non-shrink mortar, expansive mortar; cement concrete, polymer cement concrete, polymer concrete, non-shrinkable concrete, concrete including expansive concrete. The method for reinforcing a concrete structure according to any one of claims 1 to 22, wherein the method is provided. The method for reinforcing a concrete structure according to any one of claims 1 to 23, wherein the concrete member to be reinforced is a surface member including a box culvert wall. Furthermore, along the surface of the concrete member to be reinforced, a fiber reinforced plastic lattice material formed by intersecting a plurality of layers of continuous fibers or a lattice material to be a reinforcing bar arranged in a lattice shape is disposed,
When arranging the reinforcing material in the hole, the lattice material is fixed to the surface of the reinforced concrete member at the fixing portion of the reinforcing material,
Thickening the surface of the reinforced concrete member to which the lattice material is fixed with mortar or concrete,
The method for reinforcing a concrete structure according to any one of claims 3 to 24, comprising: In the reinforced concrete member, a hole whose axial direction is at a predetermined angle with respect to the surface of the reinforced concrete member is provided,
After inserting the reinforcing fiber bundle having flexibility into the hole, the reinforcing fiber bundle is impregnated with resin in the hole and cured to form a reinforcing material made of fiber reinforced plastic,
Filling the hole with a filler to fix the reinforcement;
A method for reinforcing a concrete structure, comprising: In the reinforced concrete member, a hole whose axial direction is at a predetermined angle with respect to the surface of the reinforced concrete member is provided,
After the resin is already impregnated but the resin is in an uncured or semi-cured state, the flexible reinforcing fiber bundle is inserted into the hole, and then the resin is cured in the hole to remove the resin from the fiber reinforced plastic. Forming a reinforcement consisting of
Filling the hole with a filler to fix the reinforcement;
A method for reinforcing a concrete structure, comprising: The method for reinforcing a concrete structure according to claim 26 or 27, wherein the hole is provided so that an axial direction of the hole is within 60 degrees with respect to a normal line direction of the reinforced concrete member. The reinforcing fiber bundle is composed of conductive fibers or mixed with conductive fibers, and when the resin is cured, the conductive fibers are energized to generate heat, 29. The method for reinforcing a concrete structure according to claim 26, 27 or 28, wherein the resin is cured. When the reinforcing material is arranged in the hole, the reinforcing fiber bundle is arranged in two holes provided in the concrete member to be reinforced in a substantially U shape, or is continuous with three or more holes. The method for reinforcing a concrete structure according to any one of claims 26 to 29, wherein the concrete structure is arranged.

Images