JPH07277802A - Carbon fiber reinforced concrete - Google Patents
Carbon fiber reinforced concreteInfo
- Publication number
- JPH07277802A JPH07277802A JP6085230A JP8523094A JPH07277802A JP H07277802 A JPH07277802 A JP H07277802A JP 6085230 A JP6085230 A JP 6085230A JP 8523094 A JP8523094 A JP 8523094A JP H07277802 A JPH07277802 A JP H07277802A
- Authority
- JP
- Japan
- Prior art keywords
- carbon fiber
- reinforced concrete
- corrosion
- fiber reinforced
- specific resistance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/38—Fibrous materials; Whiskers
- C04B14/386—Carbon
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Ceramic Engineering (AREA)
- Nanotechnology (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Inorganic Fibers (AREA)
- Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
Abstract
Description
【０００１】本発明は、改善された炭素繊維補強コンク
リートに関する。The present invention relates to improved carbon fiber reinforced concrete.
【０００２】[0002]
【従来の技術】建築、土木の材料として使われているセ
メント系マトリックスは、脆性的性質を持ち、これ単独
では構造材としての信頼性に欠けるため、これを補強、
補完する目的で従来から鉄筋が用いられている。近年、
補強繊維により構造材の特性（主に強度）の一層の改善
が検討されてきている。例えば、セメントマトリックス
に炭素繊維を適量混合することによって、従来のセメン
トコンクリートでは発現し得なかった強度特性、変形特
性、弾性特性などを付与することができ、新規構造材料
として大きな期待が寄せられている。2. Description of the Related Art Cement-based matrices used as materials for construction and civil engineering have brittle properties, and by themselves lack structural reliability as structural materials.
Reinforcing bars have been conventionally used for the purpose of complementing. recent years,
Further improvements in the properties (mainly strength) of structural materials by reinforcing fibers have been investigated. For example, by mixing an appropriate amount of carbon fiber into a cement matrix, it is possible to impart strength properties, deformation properties, elasticity properties, etc., which could not be exhibited by conventional cement concrete, and it is expected to be a new structural material. There is.
【０００３】しかしながら、炭素繊維の適用によって、
通常のコンクリートの実施工では考えられなかった基本
的な問題点が存在することが判明した。それは、金属が
炭素繊維補強コンクリートと接触すると、金属の腐食
（酸化）が著しく進行するという現象である。即ち、炭
素繊維補強コンクリートの実施工において、鉄筋や鉄
骨、型枠、結束線、アンカーファスナーやスペーサーそ
の他の金物などを使用した場合に、これらの金属が炭素
繊維補強コンクリートと接触する面で、通常のコンクリ
ートでは考えられない急速な腐食が進行する。However, due to the application of carbon fibers,
It was found that there were basic problems that could not be considered in normal concrete construction work. It is a phenomenon that when the metal comes into contact with the carbon fiber reinforced concrete, the corrosion (oxidation) of the metal remarkably progresses. That is, in the construction work of carbon fiber reinforced concrete, when using reinforcing bars and steel frames, formwork, binding wires, anchor fasteners and spacers and other hardware, in the surface where these metals come into contact with carbon fiber reinforced concrete, The rapid corrosion that cannot be considered in concrete is advanced.
【０００４】これには種々の原因が作用していると考え
られるが、その基本となるのは炭素繊維の電導性と酸化
還元電位である。即ち、炭素繊維は、極めて電導性が良
好でその電位は貴金属並みの貴な電位を有しており、こ
れより卑な鉄などの金属と、この炭素繊維が接触すると
そこに局部電池が形成され、この局部電池作用がその金
属腐食の主因となっている。従って、炭素繊維補強コン
クリートにおける金属腐食を防ぐには、炭素繊維の電導
性を下げるか、あるいは酸化還元電位を卑な電位にする
か、または炭素繊維と卑な金属との接触を断つことが考
えられる。It is thought that various causes act on this, and the basis thereof is the electrical conductivity and redox potential of the carbon fiber. That is, carbon fiber has extremely good conductivity and its potential is as noble as that of noble metal, and when a metal such as iron, which is less base than this, comes into contact with the carbon fiber, a local battery is formed there. This local battery action is the main cause of the metal corrosion. Therefore, in order to prevent metal corrosion in carbon fiber reinforced concrete, it is conceivable to reduce the conductivity of carbon fiber, make the redox potential a base potential, or break the contact between carbon fiber and base metal. To be
【０００５】従来から金属の腐食を防止すべく次のよう
な様々な工夫が試みられている。 （１）炭素繊維補強コンクリートと金属との間に樹脂、
セラミック、ゴム成分の何れかからなる電気絶縁層を形
成し、補強コンクリートを硬化させる方法（特開昭６０
−１８４８１０号公報） （２）電気絶縁層に絶縁性樹脂を用いる方法（特開昭６
０−１８６４４６号公報） （３）電気絶縁層に無機材料を用いる方法（特開昭６０
−１８６４４７号公報）及び （４）電気絶縁層にエポキシ樹脂を用いる方法（特開昭
６２−２１７４４号公報） などが知られているが、これらは主として炭素繊維と卑
な金属との接触を断つ方法を試みているものである。Various attempts have heretofore been made to prevent metal corrosion. (1) Resin between carbon fiber reinforced concrete and metal,
A method of forming an electrically insulating layer made of either a ceramic or rubber component and hardening the reinforced concrete (Japanese Patent Laid-Open No. Sho 60).
No. 184810) (2) A method of using an insulating resin for the electric insulation layer (Japanese Patent Laid-Open No. 6-186,061).
No. 0-186446) (3) Method of using an inorganic material for the electric insulating layer (Japanese Patent Laid-Open No. Sho 60)
No. 186447) and (4) a method of using an epoxy resin for the electric insulation layer (Japanese Patent Laid-Open No. 62-21744), which mainly cuts the contact between the carbon fiber and the base metal. That's what the method is trying to do.
【０００６】[0006]
【発明が解決しようとする課題】上述の従来技術は、何
れの場合においても、電気絶縁性材料で金属材を被覆す
ることにより補強コンクリート中の炭素繊維と金属が直
接に接触するのを防ぎ、絶縁しようとするものである
が、この絶縁による方法には以下に示したような問題点
がある。In any of the above-mentioned prior arts, by covering a metal material with an electrically insulating material, it is possible to prevent direct contact between carbon fiber and metal in reinforced concrete. Although it is intended to insulate, this insulation method has the following problems.
【０００７】ひとつには、型枠など広い面積で炭素繊維
補強コンクリートと接触する金属材を絶縁被覆しようと
する場合厚みムラが生じやすく、そのため部分的に絶縁
層の欠陥部分が生じて炭素繊維が直接金属に接触し、局
部電池の形成による金属腐食が起きることが挙げられ
る。また、厚みムラは、得られる炭素繊維補強コンクリ
ートの表面に微細な凹凸を形成し、塗装の仕上げに悪影
響を及ぼしかねない。[0007] One of the problems is that when a metal material that comes into contact with carbon fiber reinforced concrete over a wide area such as a formwork is to be insulation-coated, thickness unevenness is likely to occur, so that a defective portion of the insulating layer partially occurs and carbon fiber is generated. It is possible to directly contact the metal and cause metal corrosion due to the formation of a local battery. Further, the uneven thickness may form fine irregularities on the surface of the obtained carbon fiber reinforced concrete, and may adversely affect the finish of coating.
【０００８】このほかにも、例えば鉄筋や鉄骨などの場
合には、コンクリートとの接着性を考慮しなければなら
ず、また、これらを運搬移動したり施工する場合に絶縁
層の剥離が生じやすい、等が問題点として挙げられる。
従って、炭素繊維補強コンクリートを得るに際しては、
上述の不都合による制限が生じない補強コンクリートの
出現が望まれている。In addition to this, for example, in the case of a reinforcing bar or a steel frame, the adhesiveness to concrete must be taken into consideration, and the insulating layer is likely to be peeled off when carrying or moving or constructing them. , Etc. are mentioned as problems.
Therefore, when obtaining carbon fiber reinforced concrete,
It is desired to develop a reinforced concrete that is not restricted by the above-mentioned inconvenience.
【０００９】[0009]
【課題を解決するための手段】本発明者等は、これら従
来法の如き制約がなく、しかも金属腐食に対する抵抗性
に優れた炭素繊維補強コンクリートを開発すべく鋭意検
討した結果、比抵抗が高い炭素繊維補強コンクリートを
用いることにより、コンクリートと金属材とが接触する
部位における金属腐食が抑制されることを見出し本発明
に到達した。Means for Solving the Problems The inventors of the present invention have diligently studied to develop a carbon fiber reinforced concrete which is not restricted by these conventional methods and is excellent in resistance to metal corrosion. As a result, the specific resistance is high. The present inventors have found that the use of carbon fiber reinforced concrete suppresses metal corrosion in the area where the concrete and the metal material come into contact with each other, and thus reached the present invention.
【００１０】本発明の要旨とするところは、セメント成
分と炭素繊維補強コンクリートにおいて、補強コンクリ
ートの比抵抗が１００Ω・ｃｍ以上であることを特徴と
する炭素繊維補強コンクリートにある。The gist of the present invention resides in a carbon fiber reinforced concrete characterized in that the cement component and the carbon fiber reinforced concrete have a specific resistance of 100 Ω · cm or more.
【００１１】以下、本発明を詳細に説明する。本発明の
炭素繊維補強コンクリートの比抵抗は、１００Ω・ｃｍ
以上である必要があり、これによって炭素繊維補強コン
クリートと接触する金属材の腐食を抑制することができ
る。より完全に金属材の腐食を防ぐには、比抵抗が５０
０Ω・ｃｍ以上であることが好ましい。The present invention will be described in detail below. The specific resistance of the carbon fiber reinforced concrete of the present invention is 100 Ω · cm.
It is necessary to be above, and thereby, it is possible to suppress the corrosion of the metal material that comes into contact with the carbon fiber reinforced concrete. To prevent corrosion of metal materials more completely, the specific resistance should be 50
It is preferably 0 Ω · cm or more.
【００１２】本発明炭素繊維補強コンクリートの上記比
抵抗を達成するには、使用する炭素繊維の比抵抗が１．
０×１０-2Ω・ｃｍ以上のものを用いる。さらに、炭素
繊維の比抵抗が０．５×１０-1Ω・ｃｍ以上であること
がより好ましい。また、炭素繊維補強コンクリート中の
炭素繊維が高体積分率でも、炭素繊維補強コンクリート
の比抵抗を十分に高く保つには、炭素繊維の比抵抗が
１．０×１０-1Ω・ｃｍ以上であることが更に好まし
い。比抵抗が１００Ω・ｃｍ未満では金属と炭素繊維と
の接触によるガルバニック腐食が進行しやすい状態とな
る。即ち、セメントマトリックス中での、高電導性の炭
素繊維の存在はガルバニック腐食電池のカソード面積を
増大させ、いわゆる小アノード、大カソードを形成して
腐食を促進すると考えられる。In order to achieve the above specific resistance of the carbon fiber reinforced concrete of the present invention, the specific resistance of the carbon fiber used is 1.
Use the one of 0 × 10 -2 Ω · cm or more. Furthermore, the specific resistance of the carbon fiber is more preferably 0.5 × 10 −1 Ω · cm or more. Even if the carbon fiber in the carbon fiber reinforced concrete has a high volume fraction, in order to keep the specific resistance of the carbon fiber reinforced concrete sufficiently high, the specific resistance of the carbon fiber is 1.0 × 10 −1 Ω · cm or more. More preferably, If the specific resistance is less than 100 Ω · cm, galvanic corrosion due to contact between the metal and the carbon fiber is likely to proceed. That is, it is considered that the presence of highly conductive carbon fibers in the cement matrix increases the cathode area of the galvanic corrosion battery and forms so-called small anodes and large cathodes to promote corrosion.
【００１３】この確認のため、コンクリート中で起こる
金属腐食反応と、その反応に導電性の炭素繊維がどのよ
うに関与しているかを調べるために次に示す様な腐食電
位及び分極曲線の測定を行った。To confirm this, in order to investigate the metal corrosion reaction that occurs in concrete and how conductive carbon fiber is involved in the reaction, the following corrosion potential and polarization curves were measured. went.
【００１４】腐食電位は、樹脂製容器内に３ｍｍの長さ
にチョップした比抵抗：１×１０-3Ω・ｃｍの炭素繊維
を０．５容量％（Ｖf ＝０．５％）及び１．０容量％
（Ｖf＝１．０％）混練したものと、炭素繊維を混練し
ない（ＣＦなし）セメントペースト中に、鋼試片及び塩
橋を介した参照電極（Ａｇ−ＡｇＣｌ）を挿入し、北斗
電工社製ポテンショスタット（ＨＺ−１Ａ）を用い、鋼
試片と参照電極間の電位の経時変化を測定した。図１に
その結果を示す。The corrosion potential is 0.5 vol% (V f = 0.5%) and 1 of carbon fiber having a specific resistance of 1 × 10 −3 Ω · cm chopped into a resin container and having a length of 3 mm. 0.0% by volume
(V f = 1.0%) kneaded ones and a carbon paste not kneaded (no CF) cement paste into which a reference electrode (Ag-AgCl) through a steel sample and a salt bridge was inserted, and Hokuto Denko Using a potentiostat (HZ-1A) manufactured by Co., Ltd., the change with time in the potential between the steel sample and the reference electrode was measured. The result is shown in FIG.
【００１５】図１に見られるように鋼材の腐食電位は初
期に貴側に移行し、その後時間の経過とともに卑側に移
行する。通常、セメントのｐＨは１２〜１３と高アルカ
リであり、この領域では鉄は不動態を形成する。初期の
腐食電位の変化は鋼材の表面に不動態層が形成される過
渡現像によるものと考えられる。また、腐食電位の卑側
への移行は、腐食のカソード反応が酸素の還元反応であ
るとすれば、セメント中の酸素が徐々に消費され、且
つ、補給が穏やかであるために、酸素が欠乏していくた
めと思われる。As shown in FIG. 1, the corrosion potential of the steel material shifts to the noble side in the initial stage and then shifts to the base side with the passage of time. Usually, the pH of cement is as high as 12-13, and iron forms a passivation in this region. It is considered that the initial change in corrosion potential is due to transient development in which a passivation layer is formed on the surface of the steel material. Moreover, if the cathodic reaction of corrosion is a reduction reaction of oxygen, the shift of the corrosion potential to the base side is such that oxygen in the cement is gradually consumed and the supply is gentle, so that the oxygen is deficient. It seems to do.
【００１６】炭素繊維を入れないセメントペーストに比
較して炭素繊維をセメント中に分散させた場合（Ｖf ＝
０．５％及びＶf ＝１．０％）の腐食電位は貴の方へ大
きくなった。また、添加量に比例してその値は大きくな
った。これは炭素繊維上での酸素の酸化還元反応により
腐食電位が決定されるとすると、セメント中の炭素繊維
が鋼材に接触し、カソード反応が起きる部位が増大して
腐食電位が大きくなったものと考えられる。When carbon fibers are dispersed in cement as compared to cement paste containing no carbon fibers (V f =
The corrosion potential at 0.5% and V f = 1.0%) increased toward you. The value increased in proportion to the amount added. This means that if the corrosion potential is determined by the redox reaction of oxygen on the carbon fiber, the carbon fiber in the cement comes into contact with the steel material and the site where the cathodic reaction occurs increases and the corrosion potential increases. Conceivable.
【００１７】次に、腐食反応をより定量的に把握するた
めに行った分極曲線の測定について説明する。分極曲線
は、腐食電位の測定系に作用極の鋼材に対し、対極とし
てＰｔ電極を用いた３電極系で測定した。腐食電位の測
定のときと同様に参照電極にはＡｇ−ＡｇＣｌ、北斗電
工社製ポテンショスタット（ＨＺ−１Ａ）を用いた。Next, the measurement of the polarization curve carried out in order to grasp the corrosion reaction more quantitatively will be described. The polarization curve was measured by a three-electrode system using a Pt electrode as a counter electrode for the steel material of the working electrode in the corrosion potential measuring system. As with the measurement of the corrosion potential, Ag-AgCl and Potentiostat (HZ-1A) manufactured by Hokuto Denko KK were used for the reference electrode.
【００１８】図２に、金属腐食反応の模式図を示す。腐
食の定常状態ではアノード反応電流とカソード反応電流
とが等しくなるので腐食状態は２つの分極曲線の交点で
表現される。その交点の電位及び電流密度が各々腐食電
位、腐食電流密度となる。FIG. 2 shows a schematic diagram of the metal corrosion reaction. In the steady state of corrosion, the anode reaction current and the cathode reaction current are equal, so the corrosion state is represented by the intersection of two polarization curves. The potential and the current density at the intersection point are the corrosion potential and the corrosion current density, respectively.
【００１９】図３に、セメント中に比抵抗２．０×１０
-3Ω・ｃｍの炭素繊維を１．０容量％を分散させた場合
（Ｖf ＝１．０％）と炭素繊維を入れない（ＣＦなし）
場合について、セメント中に挿入した鋼材の分極挙動を
示す。セメント中への炭素繊維添加によって腐食電流が
著しく増大し、約１０倍近くも増えていることがわか
る。これからもセメント中の炭素繊維が鋼材と接触し、
腐食が著しく促進されていることを窺い知ることができ
る。As shown in FIG. 3, the specific resistance in the cement is 2.0 × 10.
-3 Ω · cm carbon fiber with 1.0% by volume dispersed (V f = 1.0%) and no carbon fiber (no CF)
In this case, the polarization behavior of the steel material inserted in the cement is shown. It can be seen that the addition of carbon fiber to the cement markedly increased the corrosion current and increased it by about 10 times. The carbon fibers in the cement will continue to come into contact with the steel,
It can be seen that the corrosion is significantly accelerated.
【００２０】以上のようにセメントと炭素繊維の接触が
避けられない場合には、炭素繊維自身の電気特性、特に
比抵抗および炭素繊維補強コンクリート中の炭素繊維の
体積分率が腐食速度の大小を左右する。言い換えると、
炭素繊維補強コンクリート自身の比抵抗が腐食速度の大
小を左右することが窺える。従って、本発明に用いるこ
とのできる炭素繊維としては、強度特性の発現に優れ、
比抵抗を含む要求性能に対してバランスのとれた特性を
有するポリアクリロニトリル系の炭素繊維が好ましい。
強度特性としてはストランド引張り強度が１００ｋｇ／
ｍｍ2 以上のものが好ましい。炭素繊維の形態は、長繊
維であっても、短繊維であっても構わない。As described above, when the contact between cement and carbon fiber is unavoidable, the electrical properties of carbon fiber itself, particularly the specific resistance and the volume fraction of carbon fiber in carbon fiber reinforced concrete, make the corrosion rate large and small. It depends. In other words,
It can be seen that the specific resistance of the carbon fiber reinforced concrete itself affects the magnitude of the corrosion rate. Therefore, the carbon fiber that can be used in the present invention is excellent in the development of strength characteristics,
A polyacrylonitrile-based carbon fiber having characteristics balanced with respect to required performance including specific resistance is preferable.
As the strength characteristics, the strand tensile strength is 100 kg /
It is preferably mm 2 or more. The form of the carbon fiber may be a long fiber or a short fiber.
【００２１】また、本発明のコンクリート中における炭
素繊維の量は、体積分率で０．１〜２０％の範囲である
が、炭素繊維補強コンクリートの強度、補強コンクリー
トコストパフォーマンスを考えると０．３〜２％の範囲
が好ましい。The amount of carbon fiber in the concrete of the present invention is in the range of 0.1 to 20% in terms of volume fraction, but is 0.3 when considering the strength of carbon fiber reinforced concrete and the cost performance of reinforced concrete. The range of 2% is preferable.
【００２２】本発明で用いる高抵抗の炭素繊維は、特に
表面処理を施さなくても、セメントと強固な接着性を示
すが、硝酸等の薬液酸化による表面処理、高温空気やオ
ゾン中での表面処理、Ａｒ，Ｏ2 ，ＣＦ3 等のガスのプ
ラズマ中での表面処理、硝酸、硫酸、水酸化ナトリウ
ム、重炭酸塩、硝酸塩、リン酸等の電解液中での電解酸
化による表面処理により、炭素繊維とセメントとの接着
性および分散性の向上を更に図ることができる。また、
無機、有機の低分子もしくは高分子を浸漬処理、化学的
蒸着法（ＣＶＤ）、物理的蒸着法（ＰＶＤ）、電解重合
等で炭素繊維表面をコーティングすることによっても接
着性、分散性の向上を図ることができる。特にアミノシ
ランカップリング剤で炭素繊維表面を処理をすることに
より、接着性および分散性を更に向上することができ
る。The high-resistivity carbon fiber used in the present invention shows a strong adhesiveness with cement even if it is not surface-treated, but the surface treatment by the oxidation of a chemical solution such as nitric acid or the surface in high temperature air or ozone is carried out. Treatment, surface treatment in plasma of gas such as Ar, O 2 and CF 3 , surface treatment by electrolytic oxidation in electrolytic solution such as nitric acid, sulfuric acid, sodium hydroxide, bicarbonate, nitrate, phosphoric acid, It is possible to further improve the adhesiveness and dispersibility of the carbon fiber and the cement. Also,
Improving adhesion and dispersibility by coating the surface of carbon fiber by dipping treatment of inorganic or organic low or high molecular weight, chemical vapor deposition (CVD), physical vapor deposition (PVD), electrolytic polymerization, etc. Can be planned. Particularly, by treating the surface of the carbon fiber with an aminosilane coupling agent, the adhesiveness and dispersibility can be further improved.
【００２３】本発明に用いる鉄筋としては、通常の補強
コンクリートに使用されているもので良く、特に制限は
ない。また、積極的に黒皮を生成させた鉄筋を使用する
ことも通常であり、この場合にはこの酸化被膜が絶縁層
として作用するため、不完全ではあるが局部電池生成の
抑制が期待できる。The reinforcing bars used in the present invention may be those used in ordinary reinforced concrete and are not particularly limited. Further, it is usual to use a reinforcing bar in which black skin is positively generated. In this case, since this oxide film acts as an insulating layer, it is possible to expect the suppression of local battery generation although it is incomplete.
【００２４】本発明における炭素繊維補強コンクリート
は、セメントマトリックス中に炭素繊維を分散させたも
のであれば砂や砂利などの骨材の有無やその量の多少、
或いは各種の添加剤や混和剤の量の多少を問わず、更に
はセメントの種類を問わず、炭素繊維の電導性による局
部電池形成に基づく金属腐食に対して、防止効果を発揮
するものである。The carbon fiber reinforced concrete according to the present invention has the presence or absence of aggregate such as sand and gravel and the amount thereof as long as carbon fiber is dispersed in a cement matrix.
Or, regardless of the amount of various additives and admixtures, and regardless of the type of cement, it exhibits an effect of preventing metal corrosion due to local battery formation due to the conductivity of carbon fiber. .
【００２５】[0025]
【実施例】以下に、実施例に基づいて、より具体的に本
発明を説明する。 ［実施例１〜３］，［比較例１，２］ ポリアクリロニトリル繊維を原料とし、炭素化焼成温度
６００℃（実施例１に使用）、８００℃（実施例２に使
用）、９００℃（実施例３に使用）及び１３００℃（比
較例１に使用）で処理した炭素繊維のストランド強度お
よび比抵抗を表１に示す。EXAMPLES The present invention will be described in more detail based on the following examples. [Examples 1 to 3], [Comparative Examples 1 and 2] Using polyacrylonitrile fiber as a raw material, carbonization and firing temperature 600 ° C (used in Example 1), 800 ° C (used in Example 2), 900 ° C (implemented) Table 1 shows the strand strength and the specific resistance of the carbon fiber treated at Example 3) and at 1300 ° C. (used for Comparative Example 1).
【００２６】[0026]
【表１】 [Table 1]
【００２７】得られた炭素繊維を表２に示す配合のセメ
ントペースト中に容積分率１％の割合で混練し実施例１
〜３及び比較例１を得た。その炭素繊維補強コンクリー
トの中に、＃４００のサンドペーパーで研磨し、アセト
ンで十分脱脂した黒皮なし普通鉄筋を埋設し、４０℃×
５時間の蒸気養生を施した後、オートクレーブ中で１８
０℃×１０気圧×５時間の腐食加速試験（第１回）を実
施した後、および、さらに、同じ条件でオートクレーブ
中で処理（第２回）後に、コンクリート中から取り出
し、その腐食状況として鋼材表面の腐食発生率（腐食面
積／全表面積×１００％）を調べた。その結果を表３に
示した。比較例２として炭素繊維なしで実施例と同様に
して、鉄筋の腐食状況を調べた。その結果も併せて表３
に示した。The carbon fiber obtained was kneaded in a cement paste having the composition shown in Table 2 at a volume fraction of 1% to obtain Example 1.
3 and Comparative Example 1 were obtained. In the carbon fiber reinforced concrete, a normal bar without black skin, which was sanded with # 400 sandpaper and thoroughly degreased with acetone, was embedded at 40 ° C.
After steam curing for 5 hours, 18 in the autoclave
After carrying out a corrosion acceleration test (1st time) at 0 ° C. × 10 atm × 5 hours, and further after treating it in an autoclave under the same conditions (2nd time), it was taken out from the concrete, and the corrosion condition was steel material. The surface corrosion rate (corrosion area / total surface area × 100%) was examined. The results are shown in Table 3. As Comparative Example 2, the corrosion state of the reinforcing bar was examined in the same manner as in Example without the carbon fiber. The results are also shown in Table 3
It was shown to.
【００２８】[0028]
【表２】 [Table 2]
【００２９】[0029]
【表３】 [Table 3]
【００３０】表４に各実施例及び比較例１で用いた炭素
繊維を、表２に示した配合のコンクリート中に配合して
なる炭素繊維補強コンクリートの曲げ強度、および炭素
繊維補強コンクリートの比抵抗の測定結果を、比較例２
のコンクリートについても併せて示す。その時の養生は
２０℃、湿度９０％以上の湿気室で１日養生した後、脱
型し、７日間の水中養生で行なった。供試体寸法はＪＩ
Ｓ−Ｒ５２０１に準拠し、４ｃｍ×４ｃｍ×１６ｃｍで
行なった。各実施例とも低体積分率で十分な強度の発現
が確認できた。Table 4 shows the bending strength of carbon fiber reinforced concrete obtained by mixing the carbon fibers used in each of Examples and Comparative Example 1 into the concrete having the composition shown in Table 2 and the specific resistance of the carbon fiber reinforced concrete. The measurement result of Comparative Example 2
The concrete is also shown. The curing at that time was carried out by curing in a humidity chamber at 20 ° C. and a humidity of 90% or more for 1 day, then demolding, and curing for 7 days in water. Specimen size is JI
According to S-R5201, the measurement was performed at 4 cm × 4 cm × 16 cm. In each of the examples, the expression of sufficient strength was confirmed at a low volume fraction.
【００３１】[0031]
【表４】 [Table 4]
【００３２】[0032]
【発明の効果】本発明の炭素繊維補強コンクリートは、
極めて比抵抗が高く、強度が高い炭素繊維を用いている
ため、コンクリート中の鉄筋、鉄骨等金属の腐食に対す
る抵抗性に優れ、且つ高い曲げ強度を達成できた。The carbon fiber reinforced concrete of the present invention is
Since carbon fiber, which has extremely high specific resistance and high strength, is used, excellent resistance to corrosion of metal such as rebar and steel in concrete and high bending strength can be achieved.
【図面の簡単な説明】[Brief description of drawings]
【図１】セメント中の鋼材の腐食電位と時間の関係を表
すグラフである。FIG. 1 is a graph showing the relationship between the corrosion potential of steel in cement and time.
【図２】金属の腐食反応の構成図を示す。FIG. 2 shows a schematic diagram of a metal corrosion reaction.
【図３】セメント中の炭素繊維による鋼材の分極挙動を
示すグラフである。FIG. 3 is a graph showing a polarization behavior of a steel material due to carbon fibers in cement.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ０４Ｂ 14:38 Ａ 24:00） 111:26 111:90 (72)発明者 武井 吉一 東京都調布市飛田給二丁目19番１号 鹿島 建設株式会社技術研究所内 (72)発明者 末永 龍夫 東京都調布市飛田給二丁目19番１号 鹿島 建設株式会社技術研究所内 (72)発明者 里山 公治 東京都調布市飛田給二丁目19番１号 鹿島 建設株式会社技術研究所内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Office reference number FI technical display location C04B 14:38 A 24:00) 111: 26 111: 90 (72) Inventor Yoshikazu Takei Tokyo 2-19-1 Tobita-yasu, Chofu-shi Kashima Construction Co., Ltd. Technical Research Institute (72) Inventor Tatsuo Suenaga Tokyo 2-2-1 Tobita-yasu Tobita Kacho Construction Co., Ltd. Technical Research Institute (72) Inventor Satoyama Koji Tokyo 2-1-1, Tobita, Chofu-shi Kashima Construction Co., Ltd. Technical Research Institute
Claims (3)
ンクリートにおいて、補強コンクリートの比抵抗が１０
０Ω・ｃｍ以上であることを特徴とする炭素繊維補強コ
ンクリート。1. A reinforced concrete comprising a cement component and carbon fiber, wherein the reinforced concrete has a specific resistance of 10 or less.
Carbon fiber reinforced concrete characterized by having a resistance of 0 Ω · cm or more.
炭素繊維を用いてなることを特徴とする請求項１記載の
炭素繊維補強コンクリート。2. The carbon fiber reinforced concrete according to claim 1, wherein the carbon fiber has a specific resistance of 1.0 × 10 −2 Ω · cm or more.
ｍ2 以上の炭素繊維を用いてなることを特徴とする請求
項１または２記載の炭素繊維補強コンクリート。3. Strand tensile strength is 100 kg / m.
The carbon fiber reinforced concrete according to claim 1 or 2, characterized in that the carbon fiber of m 2 or more is used.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8523094A JP2876514B2 (en) | 1994-04-01 | 1994-04-01 | Carbon fiber reinforced concrete |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8523094A JP2876514B2 (en) | 1994-04-01 | 1994-04-01 | Carbon fiber reinforced concrete |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07277802A true JPH07277802A (en) | 1995-10-24 |
| JP2876514B2 JP2876514B2 (en) | 1999-03-31 |
Family
ID=13852769
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8523094A Expired - Fee Related JP2876514B2 (en) | 1994-04-01 | 1994-04-01 | Carbon fiber reinforced concrete |
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| Country | Link |
|---|---|
| JP (1) | JP2876514B2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03174342A (en) * | 1989-11-30 | 1991-07-29 | Nkk Corp | Conductive inorganic hardened body |
| JPH0474747A (en) * | 1990-07-12 | 1992-03-10 | Denki Kagaku Kogyo Kk | Conductive elastic mortar composition |
| JPH0781989A (en) * | 1993-09-10 | 1995-03-28 | Hyperion Catalysis Internatl Inc | Carbon-fibril-containing inorganic composite cured product |
| JPH07206502A (en) * | 1994-01-13 | 1995-08-08 | Onoda:Kk | Electrically conductive polymer cement mortar and its production |
| JPH07211418A (en) * | 1994-01-14 | 1995-08-11 | Osaka Gas Co Ltd | Earth resistance reducing agent and earth electrode |
-
1994
- 1994-04-01 JP JP8523094A patent/JP2876514B2/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03174342A (en) * | 1989-11-30 | 1991-07-29 | Nkk Corp | Conductive inorganic hardened body |
| JPH0474747A (en) * | 1990-07-12 | 1992-03-10 | Denki Kagaku Kogyo Kk | Conductive elastic mortar composition |
| JPH0781989A (en) * | 1993-09-10 | 1995-03-28 | Hyperion Catalysis Internatl Inc | Carbon-fibril-containing inorganic composite cured product |
| JPH07206502A (en) * | 1994-01-13 | 1995-08-08 | Onoda:Kk | Electrically conductive polymer cement mortar and its production |
| JPH07211418A (en) * | 1994-01-14 | 1995-08-11 | Osaka Gas Co Ltd | Earth resistance reducing agent and earth electrode |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2876514B2 (en) | 1999-03-31 |
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