JPH0617254B2 - Method for preventing deterioration of curing concrete - Google Patents
Method for preventing deterioration of curing concreteInfo
- Publication number
- JPH0617254B2 JPH0617254B2 JP61122700A JP12270086A JPH0617254B2 JP H0617254 B2 JPH0617254 B2 JP H0617254B2 JP 61122700 A JP61122700 A JP 61122700A JP 12270086 A JP12270086 A JP 12270086A JP H0617254 B2 JPH0617254 B2 JP H0617254B2
- Authority
- JP
- Japan
- Prior art keywords
- aggregate
- concrete
- lithium
- reaction
- cement
- 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.)
- Expired - Fee Related
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
- C04B14/02—Granular materials, e.g. microballoons
- C04B14/04—Silica-rich materials; Silicates
- C04B14/045—Alkali-metal containing silicates, e.g. petalite
-
- 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
- C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators, shrinkage compensating agents
- C04B22/06—Oxides, Hydroxides
- C04B22/062—Oxides, Hydroxides of the alkali or alkaline-earth metals
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Civil Engineering (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、アルカリ骨材反応を起す骨材が配合された硬
化コンクリートの劣化を防止する方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for preventing deterioration of hardened concrete mixed with an aggregate that causes an alkaline aggregate reaction.
コンクリートは、基本成分としてセメント、骨材及び水
を配合することによりつくられる。その骨材として従来
より砂利が用いられていたが、良質の砂利の産出量が次
第に不足するようになり、これを補うために、また、入
手の利便の点からも、岩石等鉱物を砕くことによって得
られる所謂砕石が、砂利に替ってコンクリートに配合さ
れる骨材として用いられている。ところが、砕石が骨材
として配合された硬化コンクリートには、長期間にわた
る使用中にその表面に網目状又は亀甲状のクラックが生
じ、それが成長するとやがて崩壊に至るという問題がし
ばしば起っている。Concrete is made by mixing cement, aggregate and water as basic components. Gravel has been used as the aggregate for a long time, but the production of high-quality gravel is gradually becoming insufficient, and to compensate for this, and for the convenience of availability, crushing minerals such as rocks. So-called crushed stone obtained by the above method is used as an aggregate mixed with concrete instead of gravel. However, hardened concrete containing crushed stone as aggregate often has a problem that during its use for a long period of time, surface-like or hexagonal cracks occur, which eventually lead to collapse. .
上記網目状又は亀甲状のクラックは、良質の砂利が骨材
として配合された硬化コンクリートが劣化することによ
りその表面に生じる直線的或いは非折線的クラックとは
明瞭に相違し、また、上記網目状又は亀甲状のクラック
が生じた硬化コンクリートの表層部からその一部を試料
として採取し、その中の骨材を顕微鏡を用いて観察する
と、骨材粒子の表面が黒く変質していたり、或いは骨材
粒子に白化した表面層が生じていることから、上記クラ
ックは、セメント中のアルカリ分と骨材との反応、所謂
アルカリ骨材反応に原因する骨材の膨脹によることが既
に知られている。The mesh-shaped or hexagonal cracks are distinctly different from the linear or non-linear cracks generated on the surface of the hardened concrete in which high-quality gravel is mixed as an aggregate and deteriorated. Or, when a part of it is taken as a sample from the surface layer of hardened concrete in which a hexagonal crack has occurred, and the aggregate in it is observed with a microscope, the surface of the aggregate particle is blackened or the bone is changed. It is already known that the above-mentioned cracks are caused by the reaction between the alkali content in the cement and the aggregate, that is, the expansion of the aggregate caused by the so-called alkali-aggregate reaction, because the whitened surface layer is generated in the aggregate particles. .
従来の技術 砕石が骨材として配合された硬化コンクリートの上記ア
ルカリ骨材反応を防ぐ方法として、コンクリート配合の
際にポゾラン物質を添加しておく方法、コンクリートを
硬化させた後その表面に合成樹脂等の防水被膜を形成さ
せる方法等が知られている。Conventional techniques As a method of preventing the above-mentioned alkali-aggregate reaction of hardened concrete in which crushed stone is mixed as an aggregate, a method of adding a pozzolanic substance during the mixing of concrete, a synthetic resin on the surface after hardening the concrete, etc. There is known a method of forming a waterproof coating of the above.
また、上記アルカリ骨材反応に原因する網目状又は亀甲
状クラックが表面に生じている劣化したコンクリート硬
化物の以後のクラックの成長或いは新たなクラックの発
生を防ぐ方法乃至その補修方法として、クラック部分を
Ｖ字状又はＵ字状に切除し、生じた凹部にモルタル、エ
ポキシ樹脂等充填剤を注入した後防水塗料で被膜する方
法も知られている。Further, as a method or a repair method for preventing the growth of new cracks or the generation of new cracks after the deterioration of hardened concrete that has a network or hexagonal cracks caused by the alkali-aggregate reaction on the surface, the cracked part There is also known a method of cutting the V into a V shape or a U shape, injecting a filler such as mortar or epoxy resin into the formed recess, and then coating with a waterproof paint.
硬化コンクリートの劣化を防ぐ方法として、特開昭58-2
0768号公報には珪酸リチウム水溶液にナフタレンスルホ
ン酸ソーダホルムアルデヒド縮合物を少量添加した液を
硬化コンクリートの表面から含浸させる方法が、また、
特開昭60-36385号公報には珪酸リチウム水溶液に低級脂
肪族アルコールを少量添加した液を用いて上記と同様に
含浸させる方法が示されている。As a method for preventing deterioration of hardened concrete, Japanese Patent Laid-Open No. 58-2
No. 0768 discloses a method of impregnating a liquid obtained by adding a small amount of sodium naphthalene sulfonate formaldehyde condensate to an aqueous solution of lithium silicate from the surface of hardened concrete,
Japanese Unexamined Patent Publication (Kokai) No. 60-36385 discloses a method of impregnating a lithium silicate aqueous solution with a small amount of a lower aliphatic alcohol added in the same manner as above.
発明が解決しようとする問題点 上記ポゾラン物質を添加しておく方法、硬化コンクリー
ト表面に防水被膜を形成させておく方法等によっては、
硬化コンクリートが長期にわたって、特に屋外で使用さ
れるときには、コンクリート表面にアルカリ骨材反応に
基づくクラックが生起する。また、上記クラックの生じ
たコンクリートからクラック部を取り除き、新たな充填
剤で埋め戻す方法は、施工が容易でないのみならず、こ
の補修後長期間を経過するとやはり上記同様クラックが
生じる。Problems to be Solved by the Invention Depending on the method of adding the pozzolanic substance, the method of forming a waterproof coating on the surface of the hardened concrete, and the like,
When the hardened concrete is used for a long period of time, especially outdoors, cracks are generated on the surface of the concrete due to an alkali-aggregate reaction. In addition, the method of removing the cracked portion from the cracked concrete and backfilling with a new filler is not only easy in construction, but also after a long period of time after the repair, cracks are generated as described above.
施工が簡易であって、比較的好ましい特開昭58-20768号
公報及び特開昭60-36385号公報等に記載の方法でも、硬
化コンクリートの表面から溶液が含浸する深さに限界が
あり、また、アルカリ骨材反応を起す骨材が配合された
硬化コンクリートに対しては、長期間経過後にはやはり
網目状又は亀甲状クラックが起り易い。Even the method described in JP-A-58-20768 and JP-A-60-36385, which are relatively easy to install and are relatively preferable, have a limit in the depth of solution impregnation from the surface of the hardened concrete, Further, with respect to hardened concrete mixed with an aggregate that causes an alkaline aggregate reaction, after a long time, reticulated or hexagonal cracks are likely to occur.
本発明の目的は、アルカリ骨材反応を起す骨材が配合さ
れた硬化コンクリートのアルカリ骨材反応による劣化を
簡易かつ完全に防ぐ方法を提供することにある。An object of the present invention is to provide a method for easily and completely preventing deterioration of hardened concrete containing an aggregate that causes an alkaline aggregate reaction due to an alkaline aggregate reaction.
問題点を解決するための手段 本発明によるアルカリ骨材反応を起す骨材を含有する硬
化コンクリートの劣化防止方法は、アルカリ骨材反応を
起す骨材を用いてコンクリートを、大気圧下、８０℃以
下の温度で硬化させ調整する際に、リチウム含有鉱物の
粉末をセメントに対しＬｉ２Ｏとして０．０１〜５重量
％量コンクリートに含有させることを特徴とする。Means for Solving the Problems A method for preventing deterioration of hardened concrete containing an aggregate that causes an alkaline aggregate reaction according to the present invention is a method in which concrete is prepared using an aggregate that causes an alkaline aggregate reaction at 80 ° C. under atmospheric pressure. When curing and adjusting at the following temperature, the lithium-containing mineral powder is contained in concrete in an amount of 0.01 to 5% by weight as Li 2 O with respect to the cement.
本発明の方法が適用されるコンクリートは、水和反応に
よって硬化する通常のセメントと水とアルカリ骨材反応
を起す骨材を主成分として含有するものである。用いら
れるセメントの例としては、普通ポルトランドセメン
ト、早強ポルトランドセメント、中庸熱ポルトランドセ
メント等が挙げられる。これらセメント中には、通常、
酸化物換算で０．５〜１．５重量％程度のアルカリ分、
例えば、Na2O，K2O等が含まれる。The concrete to which the method of the present invention is applied contains, as a main component, ordinary cement which is hardened by a hydration reaction, and water and an aggregate which causes an alkaline aggregate reaction. Examples of the cement used include ordinary Portland cement, early-strength Portland cement, moderate heat Portland cement and the like. In these cements,
Alkali content of about 0.5 to 1.5% by weight in terms of oxide,
For example, Na 2 O, K 2 O and the like are included.
本発明の方法が適用されるコンクリートに含まれる骨材
は、岩石等鉱物を砕くことにより得られるものであり、
これら鉱物の例としては、蛋白石、玉髄、珪酸質苦土質
石灰岩、流紋岩、安山岩、凝灰岩、石英安山岩、粗面
岩、黒曜岩、輝石岩、トリジマイト、クリストバライ
ト、各種チャート、フリント等が挙げられる。これらの
鉱物中には、水の存在下に前記セメント中のアルカリ分
と反応する成分が含まれる。その反応性成分の例として
は、シリカ、珪酸塩、等が挙げられる。上記鉱物骨材と
セメント中のアルカリ分との反応性は一種ではなく、一
般に砕石骨材の反応性については、コンクリート中に配
合する前に試験される。Aggregate contained in concrete to which the method of the present invention is applied is obtained by crushing minerals such as rocks,
Examples of these minerals include protein stones, chalcedony, siliceous limestone limestone, rhyolite, andesite, tuff, quartz andesite, trachyte, obsidian, pyroxene, tridymite, cristobalite, various charts, flint, etc. To be These minerals include components that react with the alkali content in the cement in the presence of water. Examples of the reactive component include silica, silicate, and the like. The reactivity of the above-mentioned mineral aggregate with the alkali content in the cement is not one kind, and generally, the reactivity of the crushed stone aggregate is tested before being mixed into concrete.
その試験方法として、アルカリ分との反応性に係る化学
法としてASTM C 289の方法が、また、モルタルバー法に
よる骨材の膨脹率を測定するASTM C 227の方法が用いら
れる。As the test method, the method of ASTM C 289 is used as the chemical method relating to the reactivity with alkali components, and the method of ASTM C 227 for measuring the expansion coefficient of aggregate by the mortar bar method is used.
本発明の方法に用いられるリチウム含有鉱物は、リチウ
ムをＬｉ２Ｏとして１〜１０重量％程度含有する天然の
岩石類であり、例えば、Ｌｉ２Ｏを３〜４重量％含有す
るリシア雲母、Ｌｉ２Ｏを３．５〜４．５重量％含有す
る葉長石、Ｌｉ２Ｏを４〜９．５重量％含有するリシア
輝石、Ｌｉ２Ｏを７〜９重量％含有する鋭角石等が挙げ
られる。本発明により、コンクリートに配合されるこれ
ら鉱物は、粒度が細かい程好ましいが、通常３００μ程
度以下に粉砕されたものでよい。従って、これら鉱物は
粉末として配合されるが、その量としてはセメントに対
してＬｉ２Ｏとして０．０１〜５重量％となる量が好ま
しい。The lithium-containing mineral used in the method of the present invention is a natural rock containing lithium as Li 2 O in an amount of about 1 to 10% by weight. For example, lithia mica containing 3 to 4% by weight of Li 2 O, Li. petalite containing 2 O 3.5 to 4.5 wt%, spodumene containing Li 2 O 4 to 9.5 wt%, sharp stones or the like containing Li 2 O 7 to 9 wt% can be mentioned . According to the present invention, it is preferable that these minerals to be added to concrete have a finer particle size, but they may be crushed to a particle size of about 300 μ or less. Therefore, these minerals are blended as a powder, and the amount thereof is preferably 0.01 to 5% by weight as Li 2 O based on the cement.
本発明によるコンクリートの調整及び硬化は通常の方法
でよく、例えば、主成分として所定量の上記セメント、
骨材及び水を配合する際、上記リチウム含有鉱物の粉末
を、セメント中均一混合となるように添加することによ
り容易に行うことができる。また、コンクリートの硬化
は、大気圧下、８０℃以下の温度で常法により容易に行
い得る。Preparation and hardening of concrete according to the present invention may be a conventional method, for example, a predetermined amount of the cement as a main component,
When the aggregate and water are blended, it can be easily performed by adding the lithium-containing mineral powder so as to be uniformly mixed in the cement. Further, the hardening of concrete can be easily performed by a conventional method at a temperature of 80 ° C. or lower under atmospheric pressure.
本発明のコンクリートには、本発明の目的が達成される
限り他の任意の成分、例えば、通常用いられる各種混和
剤等を含有させてもよい。場合によっては、例えば、亜
硝酸リチウム、水酸化リチウム等を併用添加すると更に
好ましい硬化コンクリートが得られる。The concrete of the present invention may contain other optional components such as various commonly used admixtures as long as the object of the present invention is achieved. Depending on the case, more preferable hardened concrete can be obtained, for example, by adding lithium nitrite, lithium hydroxide and the like together.
更に、本発明による硬化コンクリートには、通常の防水
被膜を設けることができ、この場合にも硬化コンクリー
トの劣化防止を好ましく達成できる。これに用いられる
防水性塗材としては、通常コンクリートの防水用に用い
られるものでよく、その例としては、アクリル系樹脂水
性エマルジョン、エポキシ樹脂水性エマルジョン、スチ
レン−ブタジエンゴム水性ラテックス、アクリロニトリ
ル−ブタジエンゴム水性エマルジョン、パラフィン水性
エマルジョン、アスファルト水性エマルジョン、セメン
トペースト、モルタル、上記エマルジョンを添加したセ
メントペースト、モルタル等が挙げられる。Further, the hardened concrete according to the present invention can be provided with a usual waterproof coating, and in this case also, prevention of deterioration of the hardened concrete can be preferably achieved. The waterproof coating material used for this purpose may be one normally used for waterproofing concrete, and examples thereof include acrylic resin aqueous emulsion, epoxy resin aqueous emulsion, styrene-butadiene rubber aqueous latex, acrylonitrile-butadiene rubber. Examples thereof include aqueous emulsions, paraffin aqueous emulsions, asphalt aqueous emulsions, cement pastes, mortars, cement pastes containing the above emulsions, mortars and the like.
作用 本発明により、コンクリートを調整する際に加えられる
リチウム含有鉱物は、硬化コンクリートのアルカリ骨材
反応を防ぎ、長期間にわたって屋外使用しても硬化コン
クリートに網目状又は亀甲状クラックを生じさせない。
この効果は、コンクリート中でこのリチウム含有鉱物か
ら、アルカリ骨材反応を防ぐ作用をするリチウム化合物
が徐々に放出されることによるものと考えられる。従っ
て、加えられるリチウム含有鉱物は、粒度の細かいもの
をコンクリート中に均一に混合させることが好ましい。
通常、アルカリ骨材反応を起す硬化コンクリートでは、
その反応は徐々に進行して骨材に膨脹をもたらし、これ
によって硬化コンクリートにクラックが生じるに至ると
考えられるから、このアルカリ骨材反応を防ぐに十分な
量のリチウム化合物をリチウム含有鉱物からコンクリー
ト中に放出させる必要がある。このアルカリ骨材反応を
防ぎ、硬化コンクリートのクラック生起を防ぐに有効な
リチウム含有鉱物量は、該鉱物中のリチウム分とセメン
ト中のナトリウム換算アルカリ分とのLi／Naモル比で
０．１以上、好ましくは０．３以上であることが見出さ
れた。しかし、リチウム含有鉱物の添加比率を高める
と、これとは別に加えられる骨材の配合量に影響を与え
るので、過度にリチウム含有鉱物を加えないことが好ま
しい。従って、アルカリ分の含有率が酸化物換算０．５
〜１．５重量％程度である通常のセメントに対して、粒
度３００μ程度以下のリチウム含有鉱物をＬｉ２Ｏとし
て０．０１〜５重量％程度配合するのが好ましい。Effect According to the present invention, the lithium-containing mineral added when adjusting the concrete prevents alkali-aggregate reaction of the hardened concrete, and does not cause a mesh or hexagonal crack in the hardened concrete even when it is used outdoors for a long period of time.
This effect is considered to be due to the gradual release of the lithium compound, which acts to prevent the alkali-aggregate reaction, from this lithium-containing mineral in concrete. Therefore, it is preferable that the lithium-containing mineral to be added has a fine particle size and is uniformly mixed in the concrete.
Normally, in hardened concrete that causes an alkali-aggregate reaction,
It is considered that the reaction gradually progresses and causes expansion of the aggregate, which causes cracks in the hardened concrete.Therefore, a sufficient amount of a lithium compound to prevent the alkali-aggregate reaction from the lithium-containing mineral in the concrete. It needs to be released inside. The amount of lithium-containing mineral that is effective in preventing this alkali-aggregate reaction and preventing the occurrence of cracks in hardened concrete is 0.1 or more in the Li / Na molar ratio of the lithium content in the mineral and the sodium-equivalent alkali content in the cement. , Preferably 0.3 or higher. However, if the addition ratio of the lithium-containing mineral is increased, it will affect the compounding amount of the aggregate separately added, so it is preferable not to add the lithium-containing mineral excessively. Therefore, the alkali content is 0.5 in terms of oxide.
It is preferable to add about 0.01 to 5% by weight of lithium-containing mineral having a particle size of about 300 μm or less as Li 2 O with respect to the ordinary cement of about to 1.5% by weight.
コンクリート中で上記リチウム含有鉱物がリチウム化合
物を放出する速度は小さいから、コンクリート打設後比
較的早期にアルカリ骨材反応を起すコンクリートに対し
ては、上記リチウム含有鉱物と共に亜硝酸リチウム、水
酸化リチウム等をコンクリート調整時に併用添加するこ
とによって早期に起るアルカリ骨材反応の防止が達成さ
れる。更に、本発明による硬化コンクリートの表面に防
水性被膜を設けると、その防水性が有効な期間コンクリ
ート表面から内部へ向う水の浸入を減らすことができ
る。これによって、水の介在で起るアルカリ骨材反応の
早期進行を短期間ではあるが抑制できる。また、この防
水性被膜によるアルカリ骨材反応の防止はリチウム含有
鉱物からコンクリート中に徐々に放出されるリチウム化
合物がこの防水期間にコンクリート中にアルカリ骨材反
応を防ぐに充分な量にまで蓄積されることによるとも考
えられる。Since the rate at which the above lithium-containing minerals release lithium compounds in concrete is low, for concrete that undergoes an alkali-aggregate reaction relatively early after placing concrete, together with the above lithium-containing minerals lithium nitrite and lithium hydroxide. It is possible to prevent the early reaction of alkali-aggregate by adding such substances together during the preparation of concrete. Further, by providing a waterproof coating on the surface of the hardened concrete according to the present invention, it is possible to reduce the infiltration of water from the concrete surface to the inside while the waterproof property is effective. As a result, it is possible to suppress the early progress of the alkaline-aggregate reaction caused by the intervention of water for a short period of time. In addition, the prevention of alkali-aggregate reaction by this waterproof coating is that the lithium compound gradually released from the lithium-containing mineral into the concrete is accumulated in the concrete in an amount sufficient to prevent the alkali-aggregate reaction during the waterproofing period. It is also possible that it depends on things.
実施例１〜４及び比較例 Na2O換算アルカリ分を０．５７重量％含有するセメント
と、アメカリ骨材反応を起す細骨剤４０％とアルカリ骨
材反応を起さない豊浦産標準砂骨材６０％との混合骨材
と、リチウム含有鉱物として粒度５０〜１８０μのリシ
ア輝石（Ｌｉ２Ｏ含有率８．６重量％）及び葉長石（Ｌ
ｉ２Ｏ含有率４．５重量％）を用意した。尚、上記骨材
のアルカリ骨材反応を起すことの判定は、ASTM C 289に
規定の化学法で判定した。Examples 1 to 4 and Comparative Example Cement containing 0.57% by weight of Na 2 O equivalent alkali content, 40% of fine aggregate that causes mechanical mechanical aggregate reaction, and standard sand bone from Toyoura that does not cause alkaline aggregate reaction Aggregate mixed with 60% wood, lithia pyroxene (Li 2 O content rate 8.6 wt%) with a particle size of 50 to 180 μm as a lithium-containing mineral, and feldspar (L
i 2 O content of 4.5% by weight) was prepared. In addition, the determination of causing the alkaline aggregate reaction of the above-mentioned aggregate was performed by the chemical method specified in ASTM C289.
次いで、セメントに対するNa2O量が１．２重量％となる
ように練り混ぜ水にNaOHを加えると共に、上記セメント
と混合骨材と水を１：２．２５：０．５の重量比に配合
し、更に第１表記載のＬｉ２Ｏ混入率となるように上記
リチウム含有鉱物を配合し、注型により１０cm×１０cm
×４０cmのモルタルバーに成形し、ASTM C 227に規定の
方法に準じて脱型及び養生を行うことによりモルタルバ
ーの硬化物を得た。Next, NaOH was added to the water so that the amount of Na 2 O based on the cement was 1.2% by weight, and the above cement, the mixed aggregate and water were mixed at a weight ratio of 1: 2.25: 0.5. In addition, the above-mentioned lithium-containing mineral was blended so that the mixture ratio of Li 2 O shown in Table 1 was obtained, and the mixture was cast to obtain 10 cm × 10 cm.
A mortar bar cured product was obtained by molding into a 40 cm mortar bar and demolding and curing according to the method specified in ASTM C227.
上記モルタルバーについて、硬化直後から９０日間にわ
たり膨脹率を測定したところ、第１表に記載の結果が得
られた。The expansion coefficient of the mortar bar was measured for 90 days immediately after curing, and the results shown in Table 1 were obtained.
比較例として、リチウム含有鉱物を加えない他は、上記
同様にしてモルタルバーを成形し、膨脹率を測定し第１
表記載の結果を得た。As a comparative example, a mortar bar was molded in the same manner as above except that the lithium-containing mineral was not added, and the expansion coefficient was measured.
The results shown in the table were obtained.
上記実施例１〜４の結果を比較例と対比すると、リチウ
ム含有鉱物粉末の添加により、特にそれに含まれるＬｉ
２Ｏ量がセメントに対し増大する程、膨脹率が低下する
ことが認められる。 Comparing the results of Examples 1 to 4 with the comparative example, the addition of the lithium-containing mineral powder shows that Li contained in it in particular.
It is observed that the expansion rate decreases as the amount of 2 O increases with respect to the cement.
実施例５〜６ 実施例１におけるリチウム鉱物おの添加の代りに、リチ
ウム鉱物と亜硝酸リチウム又は水酸化リチウムを併用し
て、第１表に記載のセメントに対するＬｉ２Ｏ含有率と
なるように添加した他は実施例１と同様にしてモルタル
バーを成形し、膨脹率を測定したところ、第１表に記載
の結果を得た。但し、実施例５では亜硝酸リチウムが、
また、実施例６では水酸化リチウムが用いられた。第１
表の結果は、これらリチウム化合物を併用添加すること
により、実施例１と同じＬｉ２Ｏ混入率でも更に膨脹率
を低めることができることを示している。Examples 5 to 6 Instead of adding the lithium mineral and the lithium mineral in Example 1, lithium mineral and lithium nitrite or lithium hydroxide were used in combination so that the Li 2 O content in the cement described in Table 1 was obtained. A mortar bar was molded and the expansion coefficient was measured in the same manner as in Example 1 except for the addition, and the results shown in Table 1 were obtained. However, in Example 5, lithium nitrite
Further, in Example 6, lithium hydroxide was used. First
The results in the table show that by adding these lithium compounds together, the expansion rate can be further lowered even with the same Li 2 O mixing rate as in Example 1.
発明の効果 本発明によると、粉砕された細かい粒子からなるリチウ
ム含有鉱物粉末を有効量コンクリート配合時に添加する
のみで、硬化後のコンクリートのアルカリ骨材反応によ
るクラック発生を防止でき、硬化コンクリートの劣化を
長期間防ぐことができる。従来、硬化コンクリートのア
ルカリ骨材反応による劣化を完全に防ぐには、予備テス
トに基いてこの反応を起さない骨材を選定した後、その
骨材を用いることによって行われていたが、本発明によ
れば予備テストの必要はなく、上記の如く極めて簡易に
アルカリ骨材反応を起す骨材を用いてもアルカリ骨材反
応を起さない硬化コンクリートを得ることができる。EFFECTS OF THE INVENTION According to the present invention, it is possible to prevent the occurrence of cracks due to the alkali-aggregate reaction of the concrete after hardening by only adding an effective amount of lithium-containing mineral powder consisting of pulverized fine particles to the concrete, and to deteriorate the hardened concrete. Can be prevented for a long time. Conventionally, in order to completely prevent deterioration of hardened concrete due to alkaline aggregate reaction, it was done by selecting an aggregate that does not cause this reaction based on preliminary tests and then using that aggregate. According to the invention, it is possible to obtain a hardened concrete that does not cause an alkali-aggregate reaction even if an aggregate that causes an alkali-aggregate reaction is used very simply as described above, without requiring a preliminary test.
Claims (1)
クリートを、大気圧下、８０℃以下の温度で硬化させ調
整する際に、リチウム含有鉱物の粉末をセメントに対し
Ｌｉ２Ｏとして０．０１〜５重量％量コンクリートに含
有させることを特徴とするアルカリ骨材反応を起す骨材
を含有する硬化コンクリートの劣化防止方法。1. When adjusting concrete using an aggregate that causes an alkaline aggregate reaction to cure at a temperature of 80 ° C. or less under atmospheric pressure, lithium-containing mineral powder is added to the cement as Li 2 O. A method for preventing deterioration of hardened concrete containing an aggregate that causes an alkaline aggregate reaction, which is characterized by including 0.01 to 5% by weight of the concrete.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61122700A JPH0617254B2 (en) | 1986-05-28 | 1986-05-28 | Method for preventing deterioration of curing concrete |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61122700A JPH0617254B2 (en) | 1986-05-28 | 1986-05-28 | Method for preventing deterioration of curing concrete |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62278151A JPS62278151A (en) | 1987-12-03 |
| JPH0617254B2 true JPH0617254B2 (en) | 1994-03-09 |
Family
ID=14842448
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61122700A Expired - Fee Related JPH0617254B2 (en) | 1986-05-28 | 1986-05-28 | Method for preventing deterioration of curing concrete |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0617254B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1323833C (en) * | 1987-04-28 | 1993-11-02 | Yatindra M. Joshi | Pharmaceutical compositions in the form of beadlets and method |
| US5656075A (en) * | 1995-05-10 | 1997-08-12 | W. R. Grace & Co.-Conn. | Control of expansion in concrete due to alkali silica reaction |
| CA2231183A1 (en) | 1995-09-08 | 1997-03-13 | David B. Stokes | Concrete compositions and processes for controlling alkali-silica reaction in same |
| WO1997009281A1 (en) * | 1995-09-08 | 1997-03-13 | Fmc Corporation | Cement compositions for controlling alkali-silica reactions in concrete and processes for making same |
| JP4642177B2 (en) * | 2000-01-24 | 2011-03-02 | 電気化学工業株式会社 | Sludge reducing material, centrifugal molded body using the same, and manufacturing method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5926957A (en) * | 1982-08-02 | 1984-02-13 | 旭化成株式会社 | Manufacture of calcium silicate hydrate hardened body |
-
1986
- 1986-05-28 JP JP61122700A patent/JPH0617254B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62278151A (en) | 1987-12-03 |
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