JP4285675B2 - Aggregate for hardened cement and hardened cement - Google Patents
Aggregate for hardened cement and hardened cement Download PDFInfo
- Publication number
- JP4285675B2 JP4285675B2 JP2000291893A JP2000291893A JP4285675B2 JP 4285675 B2 JP4285675 B2 JP 4285675B2 JP 2000291893 A JP2000291893 A JP 2000291893A JP 2000291893 A JP2000291893 A JP 2000291893A JP 4285675 B2 JP4285675 B2 JP 4285675B2
- Authority
- JP
- Japan
- Prior art keywords
- cement
- hardened
- aggregate
- water
- agent
- 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 - Lifetime
Links
Description
【０００１】
【発明の属する技術分野】
本発明は、セメントコンクリ−トあるいはセメントモルタル等（以下セメント硬化体という）の劣化要因を自ら阻止すると共に損傷に対し自ら治癒せしめる機能、即ち、自癒作用を有するセメント硬化体及びセメント硬化体用骨材に関する。
【０００２】
【従来の技術】
固化したセメント硬化体をそのままにしておいたり、セメント硬化体に亀裂等の欠陥が生じたまま放置しておくとセメント硬化体の表面やこの亀裂より雨水、二酸化炭素、塩分等がセメント硬化体内に浸透することでセメント硬化体が本来持っているアルカリ性が損なわれ、いわゆる中性化を起し、内部の鉄筋が錆びてしまいその結果、鉄筋が膨張しセメント硬化体を内部より破壊するといった不具合があった。この他、凍結融解、アルカリ骨材反応、化学的腐食等を引き起こしセメント硬化体の劣化を進めてしまうといった不具合もあった。
【０００３】
また雨水、二酸化炭素、塩分等がセメント硬化体内に浸透するのを防止するため表面に樹脂系塗料を塗布していた。その他、セメント硬化体中の水酸化カルシウムと反応して水不溶性物を生成する薬剤を含む防水剤・止水剤・劣化抑止剤（以下、特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤という）をセメント硬化体の表面や亀裂部に塗布し、すでに硬化したセメント硬化体内の水酸化カルシウムと反応させ水不溶性の緻密な結晶を亀裂内あるいはセメント硬化体内の微細な空隙、クラック、セメントゲル空孔等内に成長させ、亀裂や微細な空隙、クラック、セメントゲル空孔等の内部への雨水等の浸透を阻止する方法が特開平１−３２０２８４号公報、特開昭６３−１８２２４５号公報並びに特開平２−２２１５９号公報等に開示されているように公知になっている。
【０００４】
【発明が解決しようとする課題】
しかし上記前者の樹脂系塗料を塗布する方法は、初期的には問題ないが、経年変化や外部損傷等により初期の効果を永続的に期待することは困難である。
一方、後者の特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤を塗布する方法は、セメント硬化体の表面に塗布するにもかかわらず、表面に開口した亀裂のみならず表面よりかなり深部（３０〜５０ｃｍ）に存在する微細な空隙、クラック、セメントゲル空孔等へ析出する水酸化カルシウムと反応し、亀裂や微細な空隙、クラック、セメントゲル空孔等へ永続的に水不溶性の緻密な結晶を増殖させることが期待できる。しかし、亀裂の生じた後、その部位を探して個別に対応していたのでは膨大な工数がかかるうえ、的確な時期にこれを見つけ出すことができず重大な不具合に至ってしまう危険性があった。
また予防のためセメント硬化体の表面の全てに塗布することは効果が十分期待できるものの、経済的、納期的、立地条件等の面からその実現は極めて困難であった。
【０００５】
このため生コンクリ−ト、生モルタル等のセメントに直接、特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤を添加して混練することで、セメントが硬化した後、亀裂や微細な空隙、クラック、セメントゲル空孔等の内部に析出した水酸化カルシウムと反応し、水不溶性の緻密な結晶を成長させ、セメント硬化体内部への雨水等の浸透を阻止しようとする試みが成された。
【０００６】
しかし、この方法では特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤がセメントの水和反応を阻害し、かえってセメント硬化体の硬化強度を低下させてしまうといった大きな問題点があることが明らかとなった。
さらに前述のように、生コンクリ−ト、生モルタル等のセメントに直接、特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤を添加して混練すると粘性が増大し、混練に使用した大型ミキサ−の清掃作業が著しく困難になってしまう問題も生じた。
【０００７】
本発明は上記の問題に鑑みて成されたもので、上記のような特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤を、セメントの水和反応を阻害することなく内部に存在せしめた自癒作用のあるセメント硬化体及びこれに使用するセメント硬化体用骨材を提供することを目的とする。
【０００８】
【課題を解決するための手段】
上記の目的を達成するために本発明におけるセメント硬化体用骨材は、（イ）微細シリカと、水ガラスと、ケイ弗化マグネシウム又は／及び、マグネシア及びシリカを含んだケイ弗化物、を含有する水溶性弗化物と、を含む、若しくは（ロ）複数のカルボキシル基を持つ有機酸又はその塩と、マグネシウムケイ酸塩を含む鉱物と、を含む、若しくは（ハ）フマル酸やマレイン酸などの不飽和２価カルボン酸と、マグネシアと、を含む、セメント硬化体中の水酸化カルシウムと反応して水不溶性物を生成する薬剤を含む防水剤・止水剤・劣化抑止剤が混入された硬化体であることを特徴とする。
【０００９】
また本発明におけるセメント硬化体用骨材は、前記セメント硬化体中の水酸化カルシウムと反応して水不溶性物を生成する薬剤を含む防水剤・止水剤・劣化抑止剤を多孔質体より成る担体に担荷させたことを特徴とする。
また、本発明におけるセメント硬化体用骨材は、前記セメント硬化体中の水酸化カルシウムと反応して水不溶性物を生成する薬剤を含む防水剤・止水剤・劣化抑止剤と、ポルトランドセメントとを多孔質体より成る担体に担荷させたことを特徴とする。
【００１０】
さらに本発明におけるセメント硬化体用骨材は、前記セメント硬化体中の水酸化カルシウムと反応して水不溶性物を生成する薬剤を含む防水剤・止水剤・劣化抑止剤に、ポルトランドセメントを追加して得られた硬化体であることを特徴とする。
【００１１】
加えて本発明におけるセメント硬化体用骨材は、前記セメント硬化体中の水酸化カルシウムと反応して水不溶性物を生成する薬剤を含む防水剤・止水剤・劣化抑止剤に、ポルトランドセメントを追加し、これに水を加えて得られた硬化体であることを特徴とする。
【００１２】
加えて本発明におけるセメント硬化体用骨材は、前記セメント硬化体中の水酸化カルシウムと反応して水不溶性物を生成する薬剤を含む防水剤・止水剤・劣化抑止剤に、ポルトランドセメントを追加し、これに水と砂を加えて得られた硬化体であることを特徴とする。
【００１３】
加えて本発明におけるセメント硬化体用骨材は、前記セメント硬化体中の水酸化カルシウムと反応して水不溶性物を生成する薬剤を含む防水剤・止水剤・劣化抑止剤に、ポルトランドセメントを追加し、これに水と砂とファイバ−を加えて得られた硬化体であることを特徴とする。
【００１４】
加えて本発明におけるセメント硬化体用骨材は、前記担体が、空孔径０．０１〜３ｍｍ、空孔率５〜６０Ｖｏｌ％、圧縮強度３０ｋｇ／ｃｍ２以上の多孔質体であることを特徴とする。
【００１５】
加えて本発明におけるセメント硬化体用骨材は、前記硬化体が、押圧固化された後、ポルトランドセメントの水和反応により硬化したものであることを特徴とする。
【００１６】
加えて本発明におけるセメント硬化体用骨材は、前記硬化体が、吐出用ノズルにより押出し成形された連続体を切断し固化体とした後、ポルトランドセメントの水和反応により硬化したものであることを特徴とする。
【００１７】
加えて本発明におけるセメント硬化体用骨材は、セメントコンクリ−トに使用されるものであって、粒径が０．５〜４５ｍｍであることを特徴とする。
【００１８】
加えて本発明におけるセメント硬化体用骨材は、セメントモルタルに使用されるものであって、粒径が０．５〜５ｍｍであることを特徴とする。
【００１９】
加えて本発明におけるセメント硬化体用骨材は、前記押圧固化が、面圧５０ｋｇ／ｃｍ２以上あるいは線圧２００ｋｇ／ｃｍ以上の圧力で成されることを特徴とする。
【００２０】
また上記の目的を達成するために本発明におけるセメント硬化体は、請求項１乃至１４のいずれか１項に記載のセメント硬化体用骨材を含むことを特徴とする。
【００２１】
【作用】
本発明は上記のような解決手段を採用することにより、特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤を骨材内部に混入させ、該骨材とセメントとを混練するようにしたから、混練する際、特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤の外部に接する面積（表面積）が極めて少なくなった。そのため、短時間で進行するセメントの水和反応を阻害することはなくなった。一方、長時間をかけて効果を徐々に、かつ永続的に発揮するセメント硬化体に対する自癒作用については、非粉体状をした表面積の小さい骨材内の特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤からある種の自癒作用物質が徐々に放出されて、主としてセメント成分の硬化後析出する水酸化カルシウムと永続的に反応するため初期の目的（水和反応の阻害、大型ミキサ−の汚染等を回避してセメント硬化体に自癒作用をもたせる）は達成できる。
【００２２】
【発明の実施の形態】
本発明で述べる「特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤」とは特開平１−３２０２８４号公報、特開昭６３−１８２２４５号公報並びに特開平２−２２１５９号公報等に開示されている即ち、必須要件として、（イ）微細シリカと、水ガラスと、ケイ弗化マグネシウム又は／及び、マグネシア及びシリカを含んだケイ弗化物、を含有する水溶性弗化物と、を含み、若しくは（ロ）複数のカルボキシル基を持つ有機酸又はその塩と、マグネシウムケイ酸塩を含む鉱物と、を含み、若しくは（ハ）フマル酸やマレイン酸などの不飽和２価カルボン酸と、マグネシアと、を含み、（イ）〜（ハ）のいずれかに必要に応じて普通ポルトランドセメントを含有するものである。そしてこれらの組成物は、セメント硬化体の防水剤・止水剤・劣化抑止剤として広く一般に市販されている物を適宜選定して使用することができる。
【００２３】
なお以下の実施例においてはフマル酸、微細オリビンサンド（ケイ酸マグネシウム鉱物）、ポゾラン（微細シリカ）、普通ポルトランドセメントを含むものを試料１とし、ポゾラン（微細シリカ）、水ガラス、マグネシア、ケイ弗化物、普通ポルトランドセメントを含むものを試料２として使用した。
【００２４】
本発明で述べる担体とは、表面からその内部に連通する空隙や空孔を有し、その空隙や空孔内に物質を担う事のできる固体をいう。また担荷とは担体に物質を担わせる事をいう。多孔質体よりなる担体としては、砂等の耐熱性のある粒子状無機物にホウロウ等のガラス質をバインダ−として加え、これを焼成することで得られる多孔質体や連泡性スポンジの表面にセラミックをコ−ティングした後、これを焼成して得られるスケルトン状物の他、砂等の粒子状無機物やフェノ−ル樹脂等の粒子状有機物に対しエポシキ樹脂あるいは不飽和ポリエステル樹脂をバインダ−として加え、これを硬化させることで得られる多孔質体等、水に対し容易に溶解しない多孔質体であればいずれも使用することが可能である。
【００２５】
なおファイバ−を加える理由は、セメント硬化体用骨材の強度を高めるためである。生コンクリ−ト等へ本発明によるセメント硬化体用骨材を加えて混練したり、打設時にポンプ輸送した際、本発明によるセメント硬化体用骨材の崩壊を防止するうえで重要である。さらに本発明によるセメント硬化体用骨材自体の強度を高めることで硬化したセメント硬化体の強度を維持するためにも重要である。
【００２６】
そして、ここで使用するファイバ−としては、ステンレス鋼、鉄等の材料を特殊な切削技術を用いて非直線状に作成した金属繊維、ポリアクリロニトリル繊維等の合成樹脂繊維、炭素繊維、ガラス繊維等を挙げることができる。
さらに、これらの繊維は、本発明によるセメント硬化体用骨材中にファイバ−ボ−ルができないように十分に分散し存在することが骨材補強の目的からして重要であり、粉体状の材料混合時予めファイバ−を十分に分散させた後、水を加え混練するのが適切である。
【００２７】
【実施例１】
３号相当（粒径１０００μｍ程度）のケイ砂１００部に対し、融点６５０℃のホウロウ３０部を加え混合した。この混合物１００部に対し１次バインダ−として硬化剤を含み焼成過程で蒸発する成分を含むエチルシリケ−ト加水分解物を２５部加え十分撹拌・混合した。
この混合物を成形しφ２０ｍｍ×長さ２０ｍｍの１次成形体を得た。この１次成形体を６００〜７００℃で５時間焼成し、２次成形体を得た。
ケイ砂粒子間で空孔を形成すると共に焼成することによりエチルシリケ−ト加水分解物中の蒸発成分が蒸発して空孔を生じる。
この２次成形体の物性は、空孔径０．５〜１．５ｍｍ、空孔率約３５Ｖｏｌ％、圧縮強度３００〜３５０ｋｇ／ｃｍ２であった。
上記２次成形体へ、水６０部に対し前記試料１を１００部分散・懸濁したスラリ−を含浸せしめた。
常温・大気中にて１日間放置した後、常温・１００％の湿度雰囲気で２７日間養生し試験用粗骨材１を得た。
【００２８】
次に試験用粗骨材１を用いて自癒作用のあるセメントコンクリ−トを作成する方法について説明する。
普通ポルトランドセメント、細骨材として土岐（岐阜県土岐市）産山砂（粒の大きさ５ｍｍ）、粗骨材として土岐産砂利（粒の大きさ５〜２５ｍｍ）、混和剤としてＡＥ減水剤、並びに水とを混合し生コンクリ−トを調製した。なお本生コンクリ−トの配合割合は、水１５６ｋｇ／ｍ３、普通ポルトランドセメント２７４ｋｇ／ｍ３、細骨材７９１ｋｇ／ｍ３、粗骨材１０５２ｋｇ／ｍ３、混和剤０．５４８ｋｇ／ｍ３である。
その後、得られた生コンクリ−ト１ｍ３に対し試験用粗骨材１を１５０個加え再度混練した。このようにして得られた試験用粗骨材１を含む生コンクリ−トを用い試験片を作成し、常温・１００％の湿度雰囲気で２８日間養生した後、円形の試料を切り出し、透水試験（アウトプット法）を行った。比較のため試験用粗骨材１のみを使用せず同様の試験片を作成し試験を行った。
【００２９】
試験の結果、前者の透水係数が２．１×１０−１０ｃｍ／ｓであったのに対し、試験用粗骨材１を使用しなかった後者の透水係数は１．９８×１０−９ｃｍ／ｓもあり、明らかに試験用粗骨材１の効果が認められた。
またφ１００ｍｍ×長さ２００ｍｍの試験片を作成し圧縮試験を行った。
前記試験用粗骨材１を使用した場合２８７ｋｇ／ｃｍ２であったのに対し、試験用粗骨材１を使用しなかった比較例では２４５ｋｇ／ｃｍ２であり、特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤を本発明による形態で加えても強度の低下は認められず、かえって強度の増加が認められた。
これらの効果を検証するため透水試験に用いた試験片と圧縮試験に用いた試験片の破面を電子顕微鏡で精査したところ、共に、試験用粗骨材１を用いた場合には、試験用粗骨材１を用いなかった場合に空隙として認められた部分に、緻密な結晶が密に存在しているのが認められた。即ち、透水試験を行った後でも水に溶解せず残存している緻密な結晶がこれらの効果に寄与していることが分かる。
【００３０】
【実施例２】
土岐産の山砂を３部、試料１を１部、水を１部加えて十分混練し、試験用粗骨材２を作成するための混合材を調製した。
この粗骨材用混合材を用いφ１５ｍｍ×長さ１５ｍｍ程度の試験用粗骨材２を作成した。
試験用粗骨材２は、常温にて１日間放置した後、常温・１００％の湿度雰囲気にて２７日間養生した。
ここで山砂（砂）を添加する目的は、試験用粗骨材２を加圧（後述の実施例４に示す加圧方法）することなしに作成するに当たり、試験用粗骨材２の強度を得るのに必要なためであるが、必ずしも不可欠なものではない。
【００３１】
次にこの試験用粗骨材２を用いて自癒作用のあるセメントコンクリ−トを作成する方法について説明する
普通ポルトランドセメント、細骨材として土岐産山砂（粒の大きさ５ｍｍ）、粗骨材として土岐産砂利（粒の大きさ５〜２５ｍｍ）、混和剤としてＡＥ減水剤、並びに水とを混合し生コンクリ−トを調製した。なお本生コンクリ−トの配合割合は、水１５６ｋｇ／ｍ３、普通ポルトランドセメント２７４ｋｇ／ｍ３、細骨材７９１ｋｇ／ｍ３、粗骨材１０５２ｋｇ／ｍ３、混和剤０．５４８ｋｇ／ｍ３である。
その後、得られた生コンクリ−ト１ｍ３に対し試験用粗骨材２を１００個加え再度混練した。このようにして得られた試験用粗骨材２を含む生コンクリ−トを用い試験片を作成し、常温・１００％の湿度雰囲気で２８日間養生した後、円形の試料を切り出し、透水試験（アウトプット法）を行った。比較のため試験用粗骨材２のみを使用せず同様の試験片を作成し試験を行った。
【００３２】
試験の結果、前者の透水係数が８．５×１０−１１ｃｍ／ｓであったのに対し、試験用粗骨材２を使用しなかった後者の透水係数は１．９８×１０−９ｃｍ／ｓもあり、明らかに試験用粗骨材２の効果が認められた。
またφ１００ｍｍ×長さ２００ｍｍの試験片を作成し圧縮試験を行った。試験用粗骨材２を使用した場合２９７ｋｇ／ｃｍ２であったのに対し、試験用粗骨材２を使用しなかった比較例では２４５ｋｇ／ｃｍ２であり、特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤を本発明による形態で加えても強度の低下は認められず、かえって強度の増加が認められた。
【００３３】
これらの効果を検証するため透水試験に用いた試験片と圧縮試験に用いた試験片の破面を電子顕微鏡で精査したところ、共に、試験用粗骨材２を用いた場合には、試験用粗骨材２を用いなかった場合に空隙として認められた部分に、緻密な結晶が密に存在しているのが認められた。即ち、透水試験を行った後でも水に溶解せず残存している緻密な結晶がこれらの効果に寄与していることが分かる。
【００３４】
【実施例３】
ケイ砂を３部、試料２を１部、水を１部加えて十分混練し、試験用細骨材３を作成するための混合材を調製した。
この細骨材用混合材を用い粒径１．５〜２．５ｍｍ程度の試験用細骨材３を作成した。
試験用細骨材３は、常温にて１日間放置した後、常温・１００％の湿度雰囲気にて２７日間養生した。
【００３５】
次にこの試験用細骨材３を用いて自癒作用のあるセメントモルタルを作成する方法を説明する。
普通ポルトランドセメント、細骨材として土岐産山砂（粒の大きさ５ｍｍ）並びに水とを混合し生モルタルを調製した。なお本生モルタルの配合割合は、普通ポルトランドセメント１部、細骨材３部、水０．６部である。
その後、得られた生モルタル１ｋｇに対し試験用細骨材３を０．００４ｋｇを加え再度混練した。
このようにして得られた試験用細骨材３を含む生モルタルを用い試験片を作成し、常温・１００％の湿度雰囲気で２８日間養生した後、円形の試料を切り出し、透水試験（アウトプット法）を行った。比較のため試験用細骨材３のみを使用せず同様の試験片を作成し試験を行った。
【００３６】
試験の結果、前者の透水係数が３．５×１０−１２ｃｍ／ｓであったのに対し、試験用細骨材３を使用しなかった後者の透水係数は５．９×１０−１１ｃｍ／ｓもあり、明らかに試験用細骨材３の効果が認められた。
またφ１００ｍｍ×長さ２００ｍｍの試験片を作成し圧縮試験を行った。
試験用細骨材３を使用した場合２５３ｋｇ／ｃｍ２であったのに対し、試験用細骨材３を使用しなかった比較例では２３０ｋｇ／ｃｍ２であり、特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤を本発明による形態で加えても強度の低下は認められず、かえって強度の増加が認められた。
【００３７】
これらの効果を検証するため透水試験に用いた試験片と圧縮試験に用いた試験片の破面を電子顕微鏡で精査したところ、共に、試験用粗骨材３を用いた場合には、試験用粗骨材３を用いなかった場合に空隙として認められた部分に、緻密な結晶が密に存在しているのが認められた。即ち、透水試験を行った後でも水に溶解せず残存している緻密な結晶がこれらの効果に寄与していることが分かる。
【００３８】
【実施例４】
試料１を１００部に対し水を５部加え十分撹拌して湿態状の試料を調製した。新東工業（株）製ブリケッティングマシン（型式：ＢＧＳ２５）を用い約１８ｍｍ×１３ｍｍの大きさの圧粉体を成形した。なお、この際の線圧は概ね１０００ｋｇ／ｃｍであった。この圧粉体を常温・１００％の湿度雰囲気にて２８日間養生し試験用粗骨材４を得た。圧粉成形した直後の成形体の圧壊強度は３ｋｇ程度しかなく、骨材として使用し得る限界であったが、２８日間養生し圧粉体中の普通ポルトランドセメントの水和反応を進行させることにより圧壊強度は２０ｋｇ程度となり、骨材として十分使用に耐えうるものとなった。
【００３９】
次にこの試験用粗骨材４を用いて自癒作用のあるセメントコンクリ−トを作成する方法について説明する。
普通ポルトランドセメント、細骨材として土岐産山砂（粒の大きさ５ｍｍ）、粗骨材として土岐産砂利（粒の大きさ５〜２５ｍｍ）、混和剤としてＡＥ減水剤、並びに水とを混合し生コンクリ−トを調製した。なお本生コンクリ−トの配合割合は、水１５６ｋｇ／ｍ３、普通ポルトランドセメント２７４ｋｇ／ｍ３、細骨材７９１ｋｇ／ｍ３、粗骨材１０５２ｋｇ／ｍ３、混和剤０．５４８ｋｇ／ｍ３である。
その後、得られた生コンクリ−ト１ｍ３に対し試験用粗骨材４を１００個加え再度混練した。このようにして得られた試験用粗骨材４を含む生コンクリ−トを用い試験片を作成し、常温・１００％の湿度雰囲気で２８日間養生した後、円形の試料を切り出し、透水試験（アウトプット法）を行った。比較のため試験用粗骨材４のみを使用せず同様の試験片を作成し試験を行った。
【００４０】
試験の結果、前者の透水係数が５．８×１０−１１ｃｍ／ｓであったのに対し、試験用粗骨材４を使用しなかった後者の透水係数は１．９８×１０−９ｃｍ／ｓもあり、明らかに試験用粗骨材４の効果が認められた。
またφ１００ｍｍ×長さ２００ｍｍの試験片を作成し圧縮試験を行った。
試験用粗骨材４を使用した場合２９１ｋｇ／ｃｍ２であったのに対し、試験用粗骨材４を使用しなかった比較例では２４５ｋｇ／ｃｍ２であり、特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤を本発明による形態で加えても強度の低下は認められず、かえって強度の増加が認められた。
【００４１】
これらの効果を検証するため透水試験に用いた試験片と圧縮試験に用いた試験片の破面を電子顕微鏡で精査したところ、共に、試験用粗骨材４を用いた場合には、試験用粗骨材４を用いなかった場合に空隙として認められた部分に、緻密な結晶が密に存在しているのが認められた。即ち、透水試験を行った後でも水に溶解せず残存している緻密な結晶がこれらの効果に寄与していることが分かる。
【００４２】
【実施例５】
前記実施例２で作成したのと同様にして圧縮用試験片を作成した。
加圧を行い、クラックの生じた時（破壊にいたる直前）の圧力Ｆ１を読み取り直ちに加圧を解除した。そのままの状態を保持しつつ、常温・１００％の湿度雰囲気にて２８日間放置した。その後、再び加圧し最高圧力Ｆ２を読み取った。
Ｆ１と比べＦ２が大きくなっていれば２８日間放置した間に自癒作用が働いたものと考えられる。
圧縮試験を行った結果、試験用粗骨材２を使用しなかった試験片はＦ２／Ｆ１＝０．９〜１．０であったのに対し、試験用粗骨材２を使用した試験片はＦ２／Ｆ１＝１．２〜１．４も有り２８日間放置した間に自癒作用が強く働いたものと考えられる。
【００４３】
本発明において、担体の空孔径を０．０１〜３ｍｍとしたのは、これより細い空孔内へは、ある種の自癒作用物質を徐々に放出する特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤が極めて侵入しにくく、本発明の効果が期待できなくなるためであり、その上限を３ｍｍとしたのは、これ以上の大きさの連続した空孔径となると担体の強度が極端に低下し、本発明による骨材を生コンクリ−ト又は生モルタルと混練する際、該骨材が崩壊してしまう危険が有るためである。
また空孔率を５〜６０Ｖｏｌ％としたのは、これより空孔率が低いと前記自癒作用物質が担荷される量が少なすぎ、自癒作用が期待できないためであり、これより空孔率が高いと担体の強度が保てなくなり、前記と同様の欠点が生じるためである。
さらに圧縮強度３０ｋｇ／ｃｍ２以上としたのは、これより強度が低いと前記同様、生コンクリ−ト又は生モルタルと混練する際、骨材が崩壊してしまう危険が有るためである。また、この骨材を加えたセメント硬化体の強度を維持するためにも前記圧縮強度は３０ｋｇ／ｃｍ２以上必要である。
【００４４】
本発明において押圧固化時の押圧力を、面圧の場合５０ｋｇ／ｃｍ２以上、線圧の場合２００ｋｇ／ｃｍ以上としたのは、これ以下の押圧力では後工程（押圧固化した後、ポルトランドセメントの水和反応により完全に硬化するまでの間）での取り扱い時に押圧固化体が崩壊してしまう危険性が大きく、製品の歩留まりが極端に悪くなるためである。
【００４５】
また押圧固化した後、水和反応を行わせるようにしたのも、本発明による骨材が生コンクリ−ト又は生モルタルとの混練時に崩壊しない強度を得るためである。
【００４６】
なお上記実施例においてはブリケッティングマシンにより圧粉成形し、得られた固化体を養生することで水和反応を進行させ硬化するようにしているが、固化体を得るにあたっては、打錠機（圧縮造粒機）を用い錠剤のように成形することも可能であるし、土練機等の吐出ノズルより連続して押出した棒状体を適当な長さに切断して得ることも可能である。これらは、いずれの方法であっても本発明による骨材を極めて早く生産できる利点がある。
【００４７】
本発明において、セメントコンクリ−トに使用される骨材の粒径を０．５〜４５ｍｍとしたのは、これ以下の骨材を作成するのが困難であるうえ、これ以下の大きさの骨材を、自癒作用を発揮させるのに十分な量、生コンクリ−トへ添加すると初期の問題点であったセメント硬化体の強度低下並びに生コンクリ−トの粘度増大による大型ミキサ−の清掃困難が生じてしまうためである。また、これ以上の大きさの骨材にすると、混練時や打設時、骨材の分離を生じやすくなり、さらには打設時にポンプ輸送することが困難になったり、型枠内に入りにくくなったりするので利用範囲が限定されてしまうためである。
そして、好ましくは粒径２〜２５ｍｍの骨材を使用するのが望ましい。
【００４８】
本発明においてセメントモルタルに使用される骨材の粒径を０．５〜５ｍｍとしたのは、これ以下の骨材を作成するのが困難であるうえ、これ以下の大きさの骨材を、自癒作用を発揮させるのに十分な量、生モルタルへ添加すると初期の問題点であったセメント硬化体の強度低下並びに生モルタルの粘度増大によるミキサ−の清掃困難が生じてしまうためである。また、これ以上の大きさの骨材にすると、生モルタルを施工する際、滑らかな仕上げが困難となってしまうためである。
そして、好ましくは粒径１〜３ｍｍの骨材を使用するのが望ましい。
【００４９】
【発明の効果】
本発明は上記の説明から明らかなように、自癒作用のある特殊な反応性薬剤を含む防水剤・止水剤・劣化抑止剤が混入された硬化体を骨材として含むセメント硬化体にしたから、セメントの水和反応を阻害することなしにセメント硬化体へ自癒作用を付与することができる等種々の効果がある。[0001]
BACKGROUND OF THE INVENTION
The present invention has a function of preventing deterioration factors such as cement concrete or cement mortar (hereinafter referred to as hardened cement) and healing itself against damage, that is, a hardened cement and a hardened cement having a self-healing action. Concerning aggregates.
[0002]
[Prior art]
If the hardened cement hardened body is left as it is or if it is left with defects such as cracks in the hardened cement body, rainwater, carbon dioxide, salt, etc. will enter the hardened cement body from the surface of the cement hardened body and this crack. By penetrating, the inherent alkalinity of the hardened cement body is impaired, so-called neutralization occurs, the internal reinforcing bars rust, and as a result, the reinforcing bars expand and destroy the hardened cement body from the inside. there were. In addition, there was a problem that the hardened cement body deteriorated by causing freeze-thawing, alkali-aggregate reaction, chemical corrosion, and the like.
[0003]
In addition, a resin-based paint has been applied to the surface to prevent rainwater, carbon dioxide, salt, and the like from penetrating into the hardened cement body. In addition, waterproofing agents / waterproofing agents / degradation inhibitors containing chemicals that react with calcium hydroxide in hardened cement to produce water-insoluble materials (hereinafter referred to as waterproofing agents / waterproofing agents containing special reactive agents) (Degradation inhibitor) is applied to the surface and cracks of the hardened cement body and reacted with calcium hydroxide in the hardened cement hardened body to form water-insoluble dense crystals in the cracks or in the hardened cement bodies. JP-A-1-320284, JP-A-63-63, and methods for preventing the penetration of rainwater or the like into the interior of a crack, fine void, crack, cement gel hole, etc. It is publicly known as disclosed in Japanese Patent No. 182245 and Japanese Patent Laid-Open No. Hei 2-22159.
[0004]
[Problems to be solved by the invention]
However, the above-mentioned method of applying the resin-based paint is initially satisfactory, but it is difficult to expect the initial effect permanently due to aging, external damage, and the like.
On the other hand, the method of applying the waterproofing agent / water-stopper / degradation inhibitor containing the latter special reactive agent is not only applied to the surface of the hardened cement body, but also from the surface to the cracks. Reacts with calcium hydroxide deposited in fine pores, cracks, cement gel vacancies, etc. existing in a very deep part (30-50cm), and permanently insoluble in cracks, fine voids, cracks, cement gel vacancies, etc. It can be expected to grow dense crystals. However, after the crack occurred, looking for the part and dealing with it individually took a lot of man-hours and could not find it at the right time, leading to a serious malfunction .
Moreover, although it can be expected that the effect is sufficiently applied to the entire surface of the hardened cement body for prevention, it has been extremely difficult to realize from the viewpoints of economy, delivery time, location conditions, and the like.
[0005]
For this reason, by adding a water-proofing agent / water-stopper / degradation inhibitor containing a special reactive agent directly to cement such as raw concrete and raw mortar, and kneading the cement, Attempts have been made to prevent the penetration of rainwater into the hardened cementitious body by reacting with calcium hydroxide precipitated in the voids, cracks, cement gel pores, etc. to grow dense water-insoluble crystals. It was done.
[0006]
However, this method has a serious problem that waterproofing agents, water-stopping agents, and deterioration inhibitors containing special reactive agents inhibit the hydration reaction of the cement, and rather reduce the hardening strength of the cemented body. It became clear.
Furthermore, as mentioned above, adding a waterproofing agent / water-stopper / degradation inhibitor containing a special reactive agent directly to cement such as raw concrete and raw mortar increases the viscosity and is used for kneading. There was also a problem that the cleaning work of the large mixer was extremely difficult.
[0007]
The present invention has been made in view of the above problems, and a waterproofing agent / water-stopper / deterioration inhibitor containing a special reactive agent as described above is contained inside without inhibiting the hydration reaction of cement. An object of the present invention is to provide a hardened cement body having self-healing action and an aggregate for a hardened cement body to be used therefor.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the aggregate for cured cement body according to the present invention is:(B) a water-soluble fluoride containing fine silica, water glass, and magnesium silicofluoride or / and silicic fluoride containing magnesia and silica, or (b) a plurality of carboxyl groups An organic acid or a salt thereof, and a mineral containing magnesium silicate, or (ha) an unsaturated divalent carboxylic acid such as fumaric acid or maleic acid, and magnesia.It is a hardened body in which a waterproofing agent, a water-stopping agent, and a deterioration inhibitor containing a chemical that reacts with calcium hydroxide in a hardened cement body to produce a water-insoluble material are mixed.
[0009]
Further, the aggregate for a hardened cement body according to the present invention is a waterproofing agent / waterproofing agent / deterioration inhibitor containing a chemical that reacts with calcium hydroxide in the hardened cement body to generate a water-insoluble material.AgentIt is characterized by being loaded on a carrier made of a porous material.
Further, the aggregate for a cement cured body according to the present invention includes a waterproofing agent, a water-stopping agent, a deterioration inhibitor, and a Portland cement containing a chemical that reacts with calcium hydroxide in the cement cured body to generate a water-insoluble material. Is carried on a carrier made of a porous material.
[0010]
Further, the aggregate for a hardened cement body according to the present invention is a waterproofing agent / water-stop agent / deterioration inhibitor containing a chemical agent that reacts with calcium hydroxide in the hardened cement body to generate a water-insoluble material.TheIt is a hardened body obtained by adding Rutland cement.
[0011]
In addition, the aggregate for a hardened cement body according to the present invention is used as a waterproofing agent, a waterstop agent, and a degradation inhibitor containing a chemical agent that reacts with calcium hydroxide in the hardened cement body to generate a water-insoluble material.TheIt is a hardened body obtained by adding Rutland cement and adding water thereto.
[0012]
In addition, the aggregate for a hardened cement body according to the present invention is used as a waterproofing agent, a waterstop agent, and a deterioration inhibitor containing a chemical that reacts with calcium hydroxide in the hardened cement body to generate a water-insoluble material.TheIt is a hardened body obtained by adding Rutland cement and adding water and sand thereto.
[0013]
In addition, the aggregate for a hardened cement body according to the present invention is used as a waterproofing agent, a waterstop agent, and a degradation inhibitor containing a chemical agent that reacts with calcium hydroxide in the hardened cement body to generate a water-insoluble material.TheIt is characterized by being a hardened body obtained by adding Rutland cement and adding water, sand and fiber thereto.
[0014]
In addition, in the aggregate for a hardened cement body according to the present invention, the carrier has a pore diameter of 0.01 to 3 mm, a porosity of 5 to 60 Vol%, and a compressive strength of 30 kg / cm.2It is the above porous body.
[0015]
In addition, the aggregate for a hardened cement body according to the present invention is characterized in that the hardened body is hardened by a hydration reaction of Portland cement after being pressed and solidified.
[0016]
In addition, the aggregate for a cement cured body in the present invention is that the cured body is cured by Portland cement hydration after cutting and solidifying a continuous body extruded by a discharge nozzle. It is characterized by.
[0017]
In addition, the aggregate for a hardened cement body according to the present invention is used for cement concrete and has a particle size of 0.5 to 45 mm.
[0018]
In addition, the aggregate for hardened cement body according to the present invention is used for cement mortar and has a particle size of 0.5 to 5 mm.
[0019]
In addition, the aggregate for a hardened cement body according to the present invention has a pressure of 50 kg / cm as a result of the pressure solidification.2It is characterized by being formed at a pressure of 200 kg / cm or more.
[0020]
In order to achieve the above object, the hardened cement body according to the present invention comprises:14It contains the aggregate for cement hardened bodies of any one of these.
[0021]
[Action]
The present invention adopts the above-described solution, so that a waterproofing agent, a water-stopping agent and a deterioration inhibitor containing a special reactive agent are mixed in the aggregate, and the aggregate and cement are kneaded. Therefore, when kneading, the area (surface area) in contact with the outside of the waterproofing agent / water-stopping agent / deterioration inhibitor containing a special reactive agent is extremely reduced. Therefore, the cement hydration reaction that proceeds in a short time is not inhibited. On the other hand, for self-healing action on hardened cement which gradually and permanently exerts its effect over a long period of time, a waterproofing agent containing a special reactive agent in aggregates with a small surface area that is non-powdered・ Some self-healing substances are gradually released from water-stopping agents and deterioration inhibitors, and primarily react with calcium hydroxide that precipitates after hardening of cement components, so the initial purpose (inhibition of hydration reaction) In other words, it is possible to achieve a self-healing effect on the hardened cement body by avoiding contamination of the large mixer.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
The “waterproofing agent / water-stopping agent / deterioration inhibitor containing a special reactive agent” described in the present invention refers to JP-A-1-320284, JP-A-63-182245, JP-A-2-22159, and the like. (I) Water-soluble fluorides containing fine silica, water glass, and magnesium silicofluoride or / and silicic fluoride containing magnesia and silica are disclosed as essential requirements. Or (b) an organic acid having a plurality of carboxyl groups or a salt thereof, and a mineral containing magnesium silicate, or (c) an unsaturated divalent carboxylic acid such as fumaric acid or maleic acid, Magnesia, and any one of (i) to (c) contains ordinary Portland cement as necessary. These compositions can be appropriately selected from those generally commercially available as waterproofing agents, water-stopping agents, and deterioration inhibitors for hardened cement bodies.
[0023]
In the following examples, a sample containing fumaric acid, fine olivine sand (magnesium silicate mineral), pozzolan (fine silica), or ordinary portland cement is used as sample 1, pozzolan (fine silica), water glass, magnesia, silicofluoride. Sample 2 containing a chemical, ordinary Portland cement was used.
[0024]
The carrier described in the present invention refers to a solid that has voids and pores communicating from the surface to the inside thereof and can carry a substance in the voids and pores. Also, loading means that a substance is carried on a carrier. As a carrier made of a porous material, a glassy material such as enamel is added as a binder to a heat-resistant particulate inorganic material such as sand, and this is fired to the surface of the porous material or open-cell sponge obtained. After coating the ceramic, in addition to the skeleton-like material obtained by firing the ceramic, an epoxy resin or an unsaturated polyester resin is used as a binder for particulate inorganic substances such as sand and particulate organic substances such as phenolic resin. In addition, any porous body that does not dissolve easily in water, such as a porous body obtained by curing this, can be used.
[0025]
The reason for adding the fiber is to increase the strength of the aggregate for cement hardened body. When the aggregate for hardened cement according to the present invention is added to raw concrete or the like and kneaded or pumped during placing, it is important for preventing the aggregate for hardened cement according to the present invention from collapsing. Furthermore, it is important to maintain the strength of the hardened cement cured body by increasing the strength of the aggregate itself for the hardened cement body according to the present invention.
[0026]
And as a fiber used here, materials such as stainless steel and iron are made non-linearly by using a special cutting technology, synthetic fiber such as polyacrylonitrile fiber, carbon fiber, glass fiber, etc. Can be mentioned.
Furthermore, it is important for the purpose of reinforcing the aggregate that these fibers are sufficiently dispersed and present in the aggregate for hardened cement according to the present invention so that fiber balls cannot be formed. It is appropriate to sufficiently disperse the fiber in advance when mixing the materials, and then add water and knead.
[0027]
[Example 1]
30 parts of enamel having a melting point of 650 ° C. were added to and mixed with 100 parts of silica sand corresponding to No. 3 (particle size of about 1000 μm). To 100 parts of this mixture, 25 parts of an ethyl silicate hydrolyzate containing a curing agent as a primary binder and containing a component that evaporates in the firing process was added and sufficiently stirred and mixed.
This mixture was molded to obtain a primary molded body of φ20 mm × length 20 mm. This primary molded body was fired at 600 to 700 ° C. for 5 hours to obtain a secondary molded body.
By forming pores between the silica sand particles and firing, the evaporation component in the ethyl silicate hydrolyzate evaporates to generate pores.
The physical properties of this secondary molded body were as follows: pore diameter of 0.5 to 1.5 mm, porosity of about 35 Vol%, and compressive strength of 300 to 350 kg / cm.2Met.
The secondary molded body was impregnated with a slurry in which 100 parts of Sample 1 was dispersed and suspended in 60 parts of water.
After leaving it to stand at room temperature and air for 1 day, it was cured at room temperature and 100% humidity for 27 days to obtain a coarse aggregate 1 for testing.
[0028]
Next, a method for producing a cement concrete having self-healing action using the test coarse aggregate 1 will be described.
Ordinary Portland cement, fine sand aggregate from Toki (Toki City, Gifu Prefecture), mountain sand (grain size 5mm), coarse aggregate as Toki gravel (grain size 5-25mm), AE water reducing agent as admixture, and A raw concrete was prepared by mixing with water. The blending ratio of this raw concrete is 156 kg / m of water.3, Ordinary Portland cement 274kg / m3, Fine aggregate 791kg / m3Coarse aggregate 1052kg / m3, Admixture 0.548kg / m3It is.
After that, the obtained raw concrete 1m3In contrast, 150 test coarse aggregates 1 were added and kneaded again. A test piece was prepared using the raw concrete containing the coarse aggregate 1 for test thus obtained, cured for 28 days at room temperature and 100% humidity, and then a circular sample was cut out and subjected to a water permeability test ( Output method). For comparison, the same test piece was prepared and tested without using only the test coarse aggregate 1.
[0029]
As a result of the test, the former hydraulic conductivity is 2.1 × 10-10The hydraulic conductivity of the latter without using the test coarse aggregate 1 was 1.98 × 10, whereas it was cm / s.-9There was also cm / s, and the effect of the coarse aggregate 1 for test was clearly recognized.
A test piece having a diameter of 100 mm and a length of 200 mm was prepared and subjected to a compression test.
287 kg / cm when the coarse aggregate 1 for test is used2In contrast, in the comparative example in which the test coarse aggregate 1 was not used, 245 kg / cm2Even when a waterproofing agent / water-stopper / deterioration inhibitor containing a special reactive agent was added in the form according to the present invention, no decrease in strength was observed, but an increase in strength was observed.
In order to verify these effects, the fracture surfaces of the test piece used in the water permeability test and the test piece used in the compression test were examined with an electron microscope. When the coarse aggregate 1 was not used, it was recognized that dense crystals were present in the portions that were recognized as voids. That is, it can be seen that the dense crystals remaining without being dissolved in water after the water permeability test contribute to these effects.
[0030]
[Example 2]
3 parts of mountain sand from Toki, 1 part of sample 1 and 1 part of water were added and kneaded thoroughly to prepare a mixed material for preparing the test coarse aggregate 2.
Using this coarse aggregate mixture, a test coarse aggregate 2 having a diameter of about 15 mm and a length of about 15 mm was prepared.
The test coarse aggregate 2 was allowed to stand at room temperature for 1 day, and then cured for 27 days at room temperature and 100% humidity.
Here, the purpose of adding mountain sand (sand) is to prepare the test coarse aggregate 2 without pressurizing (the pressurization method shown in Example 4 described later). Because it is necessary to obtain the above.
[0031]
Next, a method for producing a cement concrete having self-healing action using the coarse aggregate 2 for test will be described.
Ordinary Portland cement, Toki-san sand (grain size 5mm) as fine aggregate, Toki gravel (grain size 5-25mm) as coarse aggregate, AE water reducing agent as admixture, and water A concrete was prepared. The blending ratio of this raw concrete is 156 kg / m of water.3, Ordinary Portland cement 274kg / m3, Fine aggregate 791kg / m3Coarse aggregate 1052kg / m3, Admixture 0.548kg / m3It is.
After that, the obtained raw concrete 1m3In contrast, 100 test coarse aggregates 2 were added and kneaded again. A test piece was prepared using the raw concrete containing the test coarse aggregate 2 obtained in this way, and cured for 28 days at room temperature and 100% humidity. Then, a circular sample was cut out, and a water permeability test ( Output method). For comparison, the same test piece was prepared and tested without using only the test coarse aggregate 2.
[0032]
As a result of the test, the hydraulic conductivity of the former was 8.5 × 10-11The hydraulic conductivity of the latter without using the test coarse aggregate 2 was 1.98 × 10, whereas it was cm / s.-9There was also cm / s, and the effect of the coarse aggregate for test 2 was clearly recognized.
A test piece having a diameter of 100 mm and a length of 200 mm was prepared and subjected to a compression test. 297 kg / cm when using coarse aggregate 2 for testing2In contrast, in the comparative example in which the test coarse aggregate 2 was not used, 245 kg / cm2Even when a waterproofing agent / water-stopper / deterioration inhibitor containing a special reactive agent was added in the form according to the present invention, no decrease in strength was observed, but an increase in strength was observed.
[0033]
In order to verify these effects, the fracture surface of the test piece used in the water permeability test and the test piece used in the compression test were examined with an electron microscope. When the coarse aggregate 2 was not used, it was recognized that dense crystals were present in the portions that were recognized as voids. That is, it can be seen that the dense crystals remaining without being dissolved in water after the water permeability test contribute to these effects.
[0034]
[Example 3]
3 parts of silica sand, 1 part of sample 2 and 1 part of water were added and sufficiently kneaded to prepare a mixed material for preparing the test fine aggregate 3.
Using this fine aggregate mixture, a test fine aggregate 3 having a particle size of about 1.5 to 2.5 mm was prepared.
The test fine aggregate 3 was allowed to stand at room temperature for 1 day, and then cured for 27 days at room temperature and 100% humidity.
[0035]
Next, a method for producing a cement mortar having a self-healing action using the test fine aggregate 3 will be described.
Normal mortar was prepared by mixing ordinary Portland cement and fine sand aggregates from Toki mountain sand (grain size 5 mm) and water. The blending ratio of the raw mortar is 1 part of ordinary Portland cement, 3 parts of fine aggregate, and 0.6 part of water.
Thereafter, 0.004 kg of the test fine aggregate 3 was added to 1 kg of the obtained raw mortar and kneaded again.
A test piece was prepared using the raw mortar containing the test fine aggregate 3 obtained in this way, and after curing for 28 days at room temperature and 100% humidity, a circular sample was cut out and subjected to a water permeability test (output) Act). For comparison, similar test pieces were prepared and tested without using only the test fine aggregate 3.
[0036]
As a result of the test, the hydraulic conductivity of the former is 3.5 × 10-12The hydraulic conductivity of the latter without using the test fine aggregate 3 was 5.9 × 10, whereas it was cm / s.-11There was also cm / s, and the effect of the fine aggregate 3 for test was clearly recognized.
A test piece having a diameter of 100 mm and a length of 200 mm was prepared and subjected to a compression test.
253 kg / cm when using fine aggregate 3 for testing2In contrast, the comparative example that did not use the test fine aggregate 3 was 230 kg / cm.2Even when a waterproofing agent / water-stopper / deterioration inhibitor containing a special reactive agent was added in the form according to the present invention, no decrease in strength was observed, but an increase in strength was observed.
[0037]
In order to verify these effects, the fracture surface of the test piece used for the water permeability test and the test piece used for the compression test were examined with an electron microscope. When the coarse aggregate 3 was not used, it was recognized that dense crystals were present in the portions recognized as voids. That is, it can be seen that the dense crystals remaining without being dissolved in water after the water permeability test contribute to these effects.
[0038]
[Example 4]
A wet sample was prepared by adding 5 parts of water to 100 parts of sample 1 and stirring sufficiently. A green compact having a size of about 18 mm × 13 mm was formed using a briquetting machine (model: BGS25) manufactured by Shinto Kogyo Co., Ltd. The linear pressure at this time was approximately 1000 kg / cm. This green compact was cured for 28 days in a normal temperature and 100% humidity atmosphere to obtain a coarse aggregate 4 for testing. The crushing strength of the molded product immediately after compacting was only about 3 kg, which was the limit that could be used as an aggregate, but it was cured for 28 days by proceeding with the hydration reaction of ordinary Portland cement in the compact. The crushing strength was about 20 kg, and it was able to withstand sufficient use as an aggregate.
[0039]
Next, a method for producing a cement concrete having a self-healing action using the coarse aggregate 4 for test will be described.
Ordinary Portland cement, Toki-san sand (grain size 5mm) as fine aggregate, Toki gravel (grain size 5-25mm) as coarse aggregate, AE water reducing agent as admixture, and water A concrete was prepared. The blending ratio of this raw concrete is 156 kg / m of water.3, Ordinary Portland cement 274kg / m3, Fine aggregate 791kg / m3Coarse aggregate 1052kg / m3, Admixture 0.548kg / m3It is.
After that, the obtained raw concrete 1m3On the other hand, 100 test coarse aggregates 4 were added and kneaded again. A test piece was prepared using the raw concrete containing the test coarse aggregate 4 thus obtained, and cured for 28 days at room temperature and 100% humidity. Then, a circular sample was cut out, and a water permeability test ( Output method). For comparison, similar test pieces were prepared and tested without using only the test coarse aggregate 4.
[0040]
As a result of the test, the former hydraulic conductivity was 5.8 × 10-11In contrast to the cm / s, the hydraulic conductivity of the latter without using the test coarse aggregate 4 was 1.98 × 10.-9There was also cm / s, and the effect of the coarse aggregate for test 4 was clearly recognized.
A test piece having a diameter of 100 mm and a length of 200 mm was prepared and subjected to a compression test.
291 kg / cm when using coarse aggregate 4 for testing2In contrast, in the comparative example in which the test coarse aggregate 4 was not used, 245 kg / cm2Even when a waterproofing agent / water-stopper / deterioration inhibitor containing a special reactive agent was added in the form according to the present invention, no decrease in strength was observed, but an increase in strength was observed.
[0041]
In order to verify these effects, the fracture surfaces of the test piece used in the water permeability test and the test piece used in the compression test were examined with an electron microscope. When the coarse aggregate 4 was not used, it was confirmed that dense crystals were present in the portions that were recognized as voids. That is, it can be seen that the dense crystals remaining without being dissolved in water after the water permeability test contribute to these effects.
[0042]
[Example 5]
A compression test piece was prepared in the same manner as in Example 2.
Pressurization was performed, and the pressure F1 at the time when the crack occurred (immediately before the breakage) was read, and the pressurization was immediately released. While maintaining the state as it is, it was left for 28 days at room temperature and 100% humidity atmosphere. Thereafter, the pressure was increased again and the maximum pressure F2 was read.
If F2 is larger than F1, it is considered that the self-healing action worked during 28 days.
As a result of the compression test, the test piece not using the test coarse aggregate 2 was F2 / F1 = 0.9 to 1.0, whereas the test piece using the test coarse aggregate 2 was used. There is also F2 / F1 = 1.2 to 1.4, and it is considered that the self-healing action worked strongly after being left for 28 days.
[0043]
In the present invention, the pore diameter of the carrier is set to 0.01 to 3 mm, and a waterproofing agent containing a special reactive agent that gradually releases a certain type of self-healing substance into the pores smaller than this. This is because the water-stopping agent / deterioration inhibitor is very difficult to enter, and the effect of the present invention cannot be expected. The upper limit is set to 3 mm. When the continuous pore diameter is larger than this, the strength of the carrier is increased. This is because it is extremely lowered and there is a risk that the aggregate will collapse when the aggregate according to the present invention is kneaded with raw concrete or raw mortar.
The reason why the porosity was set to 5 to 60% by volume is that when the porosity is lower than this, the amount of the self-healing substance loaded is too small and the self-healing action cannot be expected. This is because if the porosity is high, the strength of the carrier cannot be maintained, and the same defects as described above occur.
Furthermore, compressive strength 30kg / cm2The reason for this is that if the strength is lower than this, there is a risk that the aggregate will collapse when kneaded with raw concrete or raw mortar, as described above. The compressive strength is 30 kg / cm in order to maintain the strength of the hardened cement body to which this aggregate is added.2This is necessary.
[0044]
In the present invention, the pressing force at the time of pressing and solidifying is 50 kg / cm in the case of surface pressure.2As described above, the linear pressure is set to 200 kg / cm or higher when the pressing force is less than this, it is pressed and solidified at the time of handling in the subsequent process (after pressing and solidifying until it completely cures by hydration reaction of Portland cement). This is because there is a high risk that the body will collapse, and the yield of products will be extremely poor.
[0045]
The reason why the hydration reaction is performed after pressing and solidification is to obtain the strength that the aggregate according to the present invention does not collapse when kneaded with raw concrete or raw mortar.
[0046]
In the above-described embodiment, compaction is performed by a briquetting machine, and the obtained solidified body is cured to advance the hydration reaction and harden. However, in order to obtain the solidified body, a tableting machine is used. (Compression granulator) can be used to form like a tablet, or it can be obtained by cutting a rod-like body continuously extruded from a discharge nozzle such as a kneader into an appropriate length. is there. Any of these methods has an advantage that the aggregate according to the present invention can be produced very quickly.
[0047]
In the present invention, the particle size of the aggregate used in the cement concrete is set to 0.5 to 45 mm because it is difficult to produce an aggregate smaller than this and a bone having a smaller size than this. Adding a sufficient amount of wood to self-healing action to raw concrete makes it difficult to clean large mixers due to reduced strength of hardened cement and increased viscosity of raw concrete, which were the initial problems This is because of this. In addition, if the size of the aggregate is larger than this, the aggregate is likely to be separated at the time of kneading or placing, and further, it becomes difficult to transport the pump at the time of placing or it is difficult to enter the formwork. This is because the usage range is limited.
And it is desirable to use an aggregate having a particle diameter of 2 to 25 mm.
[0048]
In the present invention, the particle size of the aggregate used in the cement mortar is set to 0.5 to 5 mm, it is difficult to create an aggregate smaller than this, and an aggregate having a size smaller than this, This is because, when added to raw mortar in an amount sufficient to exert a self-healing action, it becomes difficult to clean the mixer due to a decrease in strength of the hardened cement body and an increase in viscosity of the raw mortar, which were initial problems. In addition, if the aggregate is larger than this, smooth finishing becomes difficult when constructing raw mortar.
And it is desirable to use an aggregate having a particle diameter of 1 to 3 mm.
[0049]
【The invention's effect】
As is apparent from the above description, the present invention provides a hardened cement body including a hardened body containing a waterproofing agent, a water-stopping agent and a deterioration inhibitor containing a special reactive agent having a self-healing action as an aggregate. Therefore, there are various effects such as being able to impart a self-healing action to the hardened cement body without inhibiting the hydration reaction of the cement.
Claims (15)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000291893A JP4285675B2 (en) | 2000-09-26 | 2000-09-26 | Aggregate for hardened cement and hardened cement |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000291893A JP4285675B2 (en) | 2000-09-26 | 2000-09-26 | Aggregate for hardened cement and hardened cement |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| JP2002097045A JP2002097045A (en) | 2002-04-02 |
| JP2002097045A5 JP2002097045A5 (en) | 2006-04-13 |
| JP4285675B2 true JP4285675B2 (en) | 2009-06-24 |
Family
ID=18774912
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000291893A Expired - Lifetime JP4285675B2 (en) | 2000-09-26 | 2000-09-26 | Aggregate for hardened cement and hardened cement |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4285675B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011057520A (en) * | 2009-09-14 | 2011-03-24 | Sumitomo Osaka Cement Co Ltd | Cement admixture, method for producing the same, and cement composition, mortar and concrete each containing the cement admixture |
| JP5541776B2 (en) * | 2009-12-16 | 2014-07-09 | 電気化学工業株式会社 | Self-healing cement admixture and cement composition |
| JP5404496B2 (en) * | 2010-03-29 | 2014-01-29 | 鹿島建設株式会社 | Artificial lightweight aggregate made into smart material, its manufacturing method and concrete kneaded material |
| CN115298148A (en) | 2020-03-17 | 2022-11-04 | 陶氏东丽株式会社 | Cement composition and cured product thereof |
| KR20220150966A (en) | 2020-03-17 | 2022-11-11 | 다우 도레이 캄파니 리미티드 | Precast Concrete Forming Body |
-
2000
- 2000-09-26 JP JP2000291893A patent/JP4285675B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2002097045A (en) | 2002-04-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100894934B1 (en) | Micro-granulose particulates | |
| US11597685B2 (en) | Method for making carbonated precast concrete products with enhanced durability | |
| JPS60176978A (en) | Manufacture of high strength cement product | |
| JP2001302324A (en) | Plastic grout | |
| JP4285675B2 (en) | Aggregate for hardened cement and hardened cement | |
| JP2009084092A (en) | Mortar-based restoring material | |
| EP3946865A1 (en) | Method for making carbonated precast concrete products with enhanced durability | |
| CA2663806C (en) | The manufacturing method of construction materials using waterworks sludge | |
| CN111548109A (en) | Preparation method of natural brucite fiber modified lime-metakaolin composite mortar | |
| JP2003095715A (en) | Aggregate for hardened cement, and hardened cement | |
| JP2009083413A (en) | Manufacturing method of cellular concrete | |
| JP2003171161A (en) | Heat resisting, high strength concrete, and production method therefor | |
| JP3290171B2 (en) | Manufacturing method of porous concrete | |
| JP6764702B2 (en) | Hydraulic composition | |
| JP4409281B2 (en) | Method for producing lightweight cellular concrete | |
| JP3183429B2 (en) | Method for producing self-compacting concrete | |
| JP3158657B2 (en) | Manufacturing method of low shrinkage lightweight concrete | |
| KR101509668B1 (en) | Block of yellow siol and manufacturing method thereof | |
| JPH1045457A (en) | Nonshrinkage-hardening composition and its hardened body | |
| JP3025401B2 (en) | Manufacturing method of hydrated cured product | |
| JP3026406B2 (en) | Manufacturing method and construction method of self-smoothing cement mortar composition | |
| TW201817694A (en) | System and method for making and applying a non-portland cement-based material | |
| JP2002012465A (en) | Extrusion compact and its manufacturing method | |
| JP2004010397A (en) | Admixture for porous concrete | |
| JPH11314977A (en) | Lightweight concrete composition and its production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20001023 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20060215 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20060215 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20060215 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20090206 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20090220 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20090319 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20090319 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120403 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120403 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130403 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130403 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140403 Year of fee payment: 5 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |