JP4133569B2 - Shrinkage reducing agent for hydraulic cement composition and hydraulic cement composition - Google Patents

Description

【０００７】
式１において、
Ａ：１〜１５個のオキシエチレン単位で構成された（ポリ）オキシエチレン基、１〜１０個のオキシプロピレン単位で構成された（ポリ）オキシプロピレン基又は合計２〜２５個のオキシエチレン単位とオキシプロピレン単位とで構成されたポリオキシアルキレン基
【０００８】
また本発明は、セメント、骨材、セメント分散剤、空気連行剤、収縮低減剤及び水を含有する水硬性セメント組成物において、セメント１００重量部当たり、収縮低減剤として前記の本発明に係る水硬性セメント組成物用収縮低減剤を０．２〜１０重量部の割合で含有して成ることを特徴とする水硬性セメント組成物に係る。
【０００９】
先ず、本発明に係る水硬性セメント組成物用収縮低減剤について説明する。本発明に係る水硬性セメント組成物用収縮低減剤は式１で示される化合物から成り、具体的には５−エチル−５−ヒドロキシメチル−１，３−ジオキサンに所定のアルキレンオキサイドを付加することによって得られる化合物から成る。かかる式１で示される化合物それ自体は公知の方法で合成できる。
【００１０】
式１で示される化合物において、式１中のＡは、１）１〜１５個のオキシエチレン単位で構成された（ポリ）オキシエチレン基、２）１〜１０個のオキシプロピレン単位で構成された（ポリ）オキシプロピレン基、又は３）合計２〜２５個のオキシエチレン単位とオキシプロピレン単位とで構成されたポリオキシアルキレン基である。なかでも、式１で示される化合物としては、式１中のＡが１〜１０個のオキシエチレン単位で構成された（ポリ）オキシエチレン基又は合計２〜１５個のオキシエチレン単位とオキシプロピレン単位とで構成されたポリオキシアルキレン基である場合のものが好ましい。式１中のＡがオキシエチレン単位とオキシプロピレン単位とで構成されたポリオキシアルキレン基である場合、双方の単位の結合様式はランダム結合、ブロック結合又はこれらの双方のいずれでもよい。
【００１１】
次に、本発明に係る水硬性セメント組成物について説明する。本発明に係る水硬性セメント組成物は、セメント、骨材、セメント分散剤、空気連行剤、収縮低減剤及び水を含有するものであって、セメント１００重量部当たり、収縮低減剤として以上説明したような本発明に係る水硬性セメント組成物用収縮低減剤を０．２〜１０重量部、好ましくは０．５〜４重量部の割合で含有して成るものである。
【００１２】
本発明に係る水硬性セメント組成物に用いるセメントとしては、普通セメント、早強セメント、中庸熱セメント等の各種ボルトランドセメントの他に、高炉セメント、フライアッシュセメント、シリカフュームセメント等の各種混合セメントが挙げられる。また骨材としては、川砂、山砂、海砂、砕砂等の細骨材、川砂利、砕石、軽量骨材等の粗骨材が挙げられる。
【００１３】
本発明に係る水硬性セメント組成物に用いるセメント分散剤としては、リグニンスルホン酸、オキシカルボン酸、ナフタレンスルホン酸ホルマリン縮合物、メラミンスルホン酸ホルマリン縮合物、ポリカルボン酸系ビニル重合体及びこれらの塩等が挙げられるが、なかでもポリカルボン酸系ビニル重合体及び／又はその塩が好ましい。また空気連行剤としては、ロジン石ケン、脂肪酸アルカリ石ケン、脂肪族アルキルエーテル硫酸塩、アルキルリン酸エステル等が挙げられる。これらのセメント分散剤及び空気連行剤の使用量は調製する水硬性セメント組成物に求められるスランプや連行空気量との関係で適宜に選択する。
【００１４】
本発明に係る水硬性セメント組成物において、得られる硬化体に凍結融解作用に対する抵抗性をより充分に発揮させるためには、それがモルタルである場合には連行空気量を５〜１２容量％となるよう調製し、またそれがコンクリートである場合には連行空気量を３〜７容量％となるよう調製するのが好ましい。
【００１５】
本発明に係る水硬性セメント組成物は、それが所謂軟練りのコンクリート、具体的には練り混ぜ直後のスランプが１８cm超、通常は１８〜２５cmのコンクリートである場合に効果の発現が高い。なかでも、練り混ぜ直後の連行空気量が３〜７容量％であり且つスランプが１８〜２５cmに調製した所謂軟練りのコンクリートは、得られる硬化体の乾燥収縮を抑え、また該硬化体の凍結融解作用に対する抵抗性を高める上で優れている。
【００１６】
本発明に係る水硬性セメント組成物を調製するに際しては、本発明の効果を損なわない範囲内で、凝結促進剤、凝結遅延剤、防水剤、防腐剤、防錆剤等の他の添加剤を適宜併用することができる。
【００１７】
【発明の実施の形態】
本発明に係る水硬性セメント組成物用収縮低減剤の実施形態としては、次の１）〜８）が挙げられる。
１）５−エチル−５−ヒドロキシメチル−１，３−ジオキサン１モルにエチレンオキサイド２モルを付加した化合物（式１中のＡが２個のオキシエチレン単位で構成されたポリオキシエチレン基である場合の式１で示される化合物）から成る水硬性セメント組成物用収縮低減剤。
【００１８】
２）５−エチル−５−ヒドロキシメチル−１，３−ジオキサン１モルにエチレンオキサイド４モルを付加した化合物（式１中のＡが４個のオキシエチレン単位で構成されたポリオキシエチレン基である場合の式１で示される化合物）から成る水硬性セメント組成物用収縮低減剤。
【００１９】
３）５−エチル−５−ヒドロキシメチル−１，３−ジオキサン１モルにエチレンオキサイド７モルを付加した化合物（式１中のＡが７個のオキシエチレン単位で構成されたポリオキシエチレン基である場合の式１で示される化合物）から成る水硬性セメント組成物用収縮低減剤。
【００２０】
４）５−エチル−５−ヒドロキシメチル−１，３−ジオキサン１モルにエチレンオキサイド２モルとプロピレンオキサイド２モルとをブロック状に付加した化合物（式１中のＡが２個のオキシエチレン単位と２個のオキシプロピレン単位とで構成されたポリオキシアルキレン基である場合の式１で示される化合物）から成る水硬性セメント組成物用収縮低減剤。
【００２１】
５）５−エチル−５−ヒドロキシメチル−１，３−ジオキサン１モルにエチレンオキサイド４モルとプロピレンオキサイド４モルとをブロック状に付加した化合物（式１中のＡが４個のオキシエチレン単位と４個のオキシプロピレン単位とで構成されたポリオキシアルキレン基である場合の式１で示される化合物）から成る水硬性セメント組成物用収縮低減剤。
【００２２】
６）５−エチル−５−ヒドロキシメチル−１，３−ジオキサン１モルにエチレンオキサイド６モルとプロピレンオキサイド６モルとをランダム状に付加した化合物（式１中のＡが６個のオキシエチレン単位と６個のオキシプロピレン単位とで構成されたポリオキシアルキレン基である場合の式１で示される化合物）から成る水硬性セメント組成物用収縮低減剤。
【００２３】
７）５−エチル−５−ヒドロキシメチル−１，３−ジオキサン１モルにプロピレンオキサイド２モルを付加した化合物（式１中のＡが２個のオキシプロピレン単位で構成されたポリオキシプロピレン基である場合の式１で示される化合物）から成る水硬性セメント組成物用収縮低減剤。
【００２４】
８）５−エチル−５−ヒドロキシメチル−１，３−ジオキサン１モルにプロピレンオキサイド５モルを付加した化合物（式１中のＡが５個のオキシプロピレン単位で構成されたポリオキシプロピレン基である場合の式１で示される化合物）から成る水硬性セメント組成物用収縮低減剤。
【００２５】
また本発明に係る水硬性セメント組成物の実施形態としては、次の９）が挙げられる。
９）単位量でセメント３２０kg／ｍ^３、細骨材８００kg／ｍ^３、粗骨材９７６kg／ｍ^３及び水１８０kg／ｍ^３を含有し、且つセメント１００重量部当たりセメント分散剤としてポリカルボン酸系ビニル重合体の塩を０．１５重量部、空気連行剤としてロジン石ケンを０．０００８重量部及び収縮低減剤として前記１）〜８）のうちでいずれかの本発明に係る水硬性セメント組成物用収縮低減剤を２重量部の割合で含有して成るコンクリート。
【００２６】
以下、本発明の構成及び効果をより具体的にするため実施例等を挙げるが、本発明が該実施例に限定されるというものではない。
【００２７】
【実施例】
試験区分１（水硬性セメント組成物用収縮低減剤としての式１で示される化合物等の合成）
・実施例１〜３
ステンレス製オートクレーブに５−エチル−５−ヒドロキシメチル−１，３−ジオキサン７３１ｇ（５モル）及び触媒としての水酸化カリウム３．６ｇを投入し、攪拌しながら溶解した。反応系を完全に窒素置換した後、反応系の温度を１３０℃に昇温した。反応系の温度を１３０〜１４０℃に保ちながら、２〜４kg／cm^２の加圧条件下で、エチレンオキサイド４４０ｇ（１０モル）を逐次圧入して１時間付加反応を行なった後、２時間熟成して粗生成物を得た。粗生成物からケイ酸マグネシウム系吸着材を用いてアルカリを吸着濾過処理により除去し、水硬性セメント組成物用収縮低減剤としての化合物Ｐ−１を得た。同様にして、水硬性セメント組成物用収縮低減剤としての化合物Ｐ−２及びＰ−３を得た。
【００２８】
・実施例４〜６
ステンレス製オートクレーブに５−エチル−５−ヒドロキシメチル−１，３−ジオキサン７３１ｇ（５モル）及び触媒としての水酸化カリウム５．２ｇを投入し、攪拌しながら溶解した。反応系を完全に窒素置換した後、反応系の温度を１３０℃に昇温した。反応系の温度を１３０〜１４０℃に保ちながら、２〜４kg／cm^２の加圧条件下で、エチレンオキサイド４４０ｇ（１０モル）を逐次圧入して１時間付加反応を行なった後、１時間熟成した。更にプロピレンオキサイド５８０ｇ（１０モル）を逐次圧入して１時間付加反応を行なった後、２時間熟成して粗生成物を得た。粗生成物を前記と同様の吸着濾過処理し、水硬性セメント組成物用収縮低減剤としての化合物Ｐ−４を得た。同様にして、水硬性セメント組成物用収縮低減剤としての化合物Ｐ−５及びＰ−６を得た。
【００２９】
・実施例７及び８
ステンレス製オートクレーブに５−エチル−５−ヒドロキシメチル−１，３−ジオキサン７３１ｇ（５モル）及び触媒としての水酸化カリウム３．９ｇを投入し、攪拌しながら溶解した。反応系を完全に窒素置換した後、反応系の温度を１３０℃に昇温した。反応系の温度を１３０〜１４０℃の温度に保ちながら、２〜４kg／cm^２の加圧条件下で、プロピレンオキサイド５８０ｇ（１０モル）を逐次圧入して１時間付加反応を行なった後、２時間熟成して粗生成物を得た。粗生成物を前記と同様の吸着濾過処理し、水硬性セメント組成物用収縮低減剤としての化合物Ｐ−７を得た。同様にして、水硬性セメント組成物用収縮低減剤としての化合物Ｐ−８を得た。
【００３０】
・比較例１〜３
実施例１〜８の化合物Ｐ−１〜Ｐ−８の合成と同様にして、水硬性セメント組成物用収縮低減剤としての化合物Ｒ−１〜Ｒ−３を得た。以上で合成した各化合物の内容を表１にまとめて示した。
【００３１】
【表１】

【００３２】
表１において、
Ｒ−４：原料として用いた５−エチル−５−ヒドロキシメチル−１，３−ジオキサン
【００３３】
試験区分２（コンクリートの調製及び評価）
・実施例９〜１９及び比較例５〜１２（コンクリートの調製）
表２に記載した調合条件で、５０Ｌのパン型強制練りミキサーに普通ポルトランドセメント（比重＝３．１６、ブレーン値３３００）、細骨材（大井川水系産川砂、比重＝２．５８，ＦＭ＝２．６９）及び粗骨材（岡崎産砕石、比重＝２．６８）を順次投入して１５秒間空練りした。次いで、いずれも目標スランプが２１±１cm、目標連行空気量が４〜５容量％となるよう、セメント分散剤（竹本油脂社製のポリカルボン酸系ビニル重合体の塩からなる高性能ＡＥ減水剤、商品名チューポールＨＰ−１１）、空気連行剤（竹本油脂社製のＡＥ剤、商品名ＡＥ３００）及び試験区分１で合成した水硬性セメント組成物用収縮低減剤としての化合物を水と共に投入して練り混ぜ、コンクリートを調製した。水硬性セメント組成物用収縮低減剤としての化合物の添加量は表３にまとめて示した。
【００３４】
【表２】

【００３５】
・コンクリートの物性評価
調製した各コンクリートについて、練り混ぜ直後のスランプ及び連行空気量、並びに乾燥収縮率、凍結融解耐久性指数、圧縮強度を次のように求め、結果を表３にまとめて示した。
【００３６】
・・スランプ：練り混ぜ直後のコンクリートについてＪＩＳ−Ａ１１０１に準拠して測定した。
・・連行空気量：練り混ぜ直後のコンクリートについてＪＩＳ−Ａ１１２８に準拠して測定した。
・・乾燥収縮率：ＪＩＳ−Ａ１１２９に準拠し、２０℃×６０％ＲＨの調湿下で保存した材齢２６週の供試体をコンパレータ法により測定した。数値が小さいほど収縮が小さいことを示す。
・・凍結融解耐久性指数：ＪＩＳ−Ａ１１４８に準拠して測定し、ＡＳＴＭ−Ｃ６６６−７５の耐久性指数で計算した数値を示した。この数値は、最大値が１００で、１００に近いほど、凍結融解に対する抵抗性が優れていることを示す。
圧縮強度：ＪＩＳ−Ａ１１０８に準拠して材齢２８日で測定した。
【００３７】
【表３】

【００３８】
表３において、
添加量：セメント１００重量部に対する化合物の添加重量部
Ｒ−５：ジエチレングリコールモノノルマルブチルエーテル
Ｒ−６：ジプロピレングリコールジエチレングリコールモノノルマルブチルエーテル
【００３９】
【発明の効果】
既に明らかなように、以上説明した本発明には、調製した水硬性セメント組成物から得られる硬化体の乾燥収縮を充分に抑えることができ、同時に該硬化体に凍結融解作用に対する充分な抵抗性を与えることができるという効果がある。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shrinkage reducing agent for a hydraulic cement composition and a hydraulic cement composition using the same.
[0002]
[Prior art]
The hydraulic cement composition is generally prepared by appropriately mixing cement, aggregate, cement dispersant, air entraining agent, shrinkage reducing agent, water, and the like. Conventionally, various organic types are known as such shrinkage reducing agents (see, for example, Patent Documents 1 to 3). However, conventional shrinkage reducing agents are insufficient in the effect of suppressing the drying shrinkage of the cured product obtained from the hydraulic cement composition prepared using them, and the freeze-thaw of the cured product is particularly in cold districts. There is a problem of reducing resistance to action. These problems are significant in so-called soft concrete where the slump immediately after mixing exceeds 18 cm.
[0003]
[Patent Document 1]
Japanese Patent Publication No. 56-51148 [Patent Document 2]
Japanese Patent Publication No. 1-53223 [Patent Document 3]
JP-T-2001-518871 [0004]
[Problems to be solved by the invention]
The problem to be solved by the present invention is that, even if it is so-called soft concrete, the drying shrinkage of the cured body obtained from the prepared hydraulic cement composition can be sufficiently suppressed, and at the same time, The present invention provides a shrinkage reducing agent for a hydraulic cement composition and a hydraulic cement composition that can provide sufficient resistance to freeze-thaw action.
[0005]
[Means for Solving the Problems]
This invention which solves the said subject concerns on the shrinkage reducing agent for hydraulic cement compositions characterized by consisting of the compound shown by following formula 1.
[0006]
[Formula 1]

[0007]
In Equation 1,
A: a (poly) oxyethylene group composed of 1 to 15 oxyethylene units, a (poly) oxypropylene group composed of 1 to 10 oxypropylene units, or a total of 2 to 25 oxyethylene units A polyoxyalkylene group composed of an oxypropylene unit
The present invention also provides a hydraulic cement composition containing cement, aggregate, cement dispersant, air entraining agent, shrinkage reducing agent and water, and the water according to the present invention as a shrinkage reducing agent per 100 parts by weight of cement. The present invention relates to a hydraulic cement composition comprising a shrinkage reducing agent for a hard cement composition in a proportion of 0.2 to 10 parts by weight.
[0009]
First, the shrinkage reducing agent for hydraulic cement composition according to the present invention will be described. The shrinkage reducing agent for hydraulic cement composition according to the present invention comprises a compound represented by the formula 1, and specifically, a predetermined alkylene oxide is added to 5-ethyl-5-hydroxymethyl-1,3-dioxane. It consists of a compound obtained by The compound represented by Formula 1 can be synthesized by a known method.
[0010]
In the compound represented by Formula 1, A in Formula 1 was composed of 1) a (poly) oxyethylene group composed of 1 to 15 oxyethylene units, and 2) 1 to 10 oxypropylene units. (Poly) oxypropylene group, or 3) a polyoxyalkylene group composed of a total of 2 to 25 oxyethylene units and oxypropylene units. Among them, as the compound represented by Formula 1, A in Formula 1 is a (poly) oxyethylene group composed of 1 to 10 oxyethylene units or a total of 2 to 15 oxyethylene units and oxypropylene units. And a polyoxyalkylene group composed of When A in Formula 1 is a polyoxyalkylene group composed of oxyethylene units and oxypropylene units, the bonding mode of both units may be random bonding, block bonding, or both.
[0011]
Next, the hydraulic cement composition according to the present invention will be described. The hydraulic cement composition according to the present invention contains cement, aggregate, cement dispersant, air entraining agent, shrinkage reducing agent and water, and has been described above as a shrinkage reducing agent per 100 parts by weight of cement. Such a shrinkage reducing agent for hydraulic cement composition according to the present invention is contained in an amount of 0.2 to 10 parts by weight, preferably 0.5 to 4 parts by weight.
[0012]
Examples of the cement used in the hydraulic cement composition according to the present invention include various mixed cements such as blast furnace cement, fly ash cement, and silica fume cement, in addition to various bolt land cements such as ordinary cement, early-strength cement, and moderately hot cement. Can be mentioned. Examples of the aggregate include fine aggregates such as river sand, mountain sand, sea sand, and crushed sand, and coarse aggregates such as river gravel, crushed stone, and lightweight aggregate.
[0013]
The cement dispersant used in the hydraulic cement composition according to the present invention includes lignin sulfonic acid, oxycarboxylic acid, naphthalene sulfonic acid formalin condensate, melamine sulfonic acid formalin condensate, polycarboxylic acid vinyl polymer, and salts thereof. Among them, polycarboxylic acid vinyl polymers and / or salts thereof are preferable. Examples of the air entraining agent include rosin soap, fatty acid alkali soap, aliphatic alkyl ether sulfate, and alkyl phosphate ester. The amount of these cement dispersant and air entraining agent used is appropriately selected in relation to the slump and entraining air amount required for the hydraulic cement composition to be prepared.
[0014]
In the hydraulic cement composition according to the present invention, in order to make the obtained hardened body more fully exhibit resistance to freeze-thaw action, when it is mortar, the amount of entrained air is 5 to 12% by volume. It is preferable that the entrained air amount be adjusted to 3 to 7% by volume when it is concrete.
[0015]
The hydraulic cement composition according to the present invention is highly effective when it is so-called soft concrete, specifically, concrete having a slump of more than 18 cm, usually 18-25 cm immediately after mixing. Among them, the so-called soft-kneaded concrete in which the amount of entrained air immediately after mixing is 3 to 7% by volume and the slump is adjusted to 18 to 25 cm suppresses drying shrinkage of the obtained cured body, and also freezes the cured body. Excellent in enhancing resistance to melting action.
[0016]
When preparing the hydraulic cement composition according to the present invention, other additives such as a setting accelerator, a setting retarder, a waterproofing agent, an antiseptic, and a rust preventive agent are added within the range not impairing the effects of the present invention. It can be used together as appropriate.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the shrinkage reducing agent for hydraulic cement composition according to the present invention include the following 1) to 8).
1) Compound obtained by adding 2 mol of ethylene oxide to 1 mol of 5-ethyl-5-hydroxymethyl-1,3-dioxane (A in Formula 1 is a polyoxyethylene group composed of two oxyethylene units) A shrinkage reducing agent for a hydraulic cement composition comprising the compound of formula 1 in the case.
[0018]
2) Compound obtained by adding 4 mol of ethylene oxide to 1 mol of 5-ethyl-5-hydroxymethyl-1,3-dioxane (A in Formula 1 is a polyoxyethylene group composed of 4 oxyethylene units) A shrinkage reducing agent for a hydraulic cement composition comprising the compound of formula 1 in the case.
[0019]
3) Compound obtained by adding 7 mol of ethylene oxide to 1 mol of 5-ethyl-5-hydroxymethyl-1,3-dioxane (A in Formula 1 is a polyoxyethylene group composed of 7 oxyethylene units) A shrinkage reducing agent for a hydraulic cement composition comprising the compound of formula 1 in the case.
[0020]
4) A compound in which 2 moles of ethylene oxide and 2 moles of propylene oxide are added in a block form to 1 mole of 5-ethyl-5-hydroxymethyl-1,3-dioxane (A in Formula 1 represents two oxyethylene units and A shrinkage reducing agent for hydraulic cement composition comprising a compound represented by Formula 1 in the case of a polyoxyalkylene group composed of two oxypropylene units.
[0021]
5) A compound in which 4 moles of ethylene oxide and 4 moles of propylene oxide are added in a block form to 1 mole of 5-ethyl-5-hydroxymethyl-1,3-dioxane (A in Formula 1 represents four oxyethylene units and A shrinkage reducing agent for hydraulic cement composition comprising a compound represented by formula 1 in the case of a polyoxyalkylene group composed of four oxypropylene units.
[0022]
6) A compound in which 6 moles of ethylene oxide and 6 moles of propylene oxide are randomly added to 1 mole of 5-ethyl-5-hydroxymethyl-1,3-dioxane (A in Formula 1 represents 6 oxyethylene units and A shrinkage reducing agent for hydraulic cement composition comprising a compound represented by Formula 1 in the case of a polyoxyalkylene group composed of 6 oxypropylene units.
[0023]
7) Compound obtained by adding 2 mol of propylene oxide to 1 mol of 5-ethyl-5-hydroxymethyl-1,3-dioxane (A in Formula 1 is a polyoxypropylene group composed of two oxypropylene units) A shrinkage reducing agent for a hydraulic cement composition comprising the compound of formula 1 in the case.
[0024]
8) Compound obtained by adding 5 mol of propylene oxide to 1 mol of 5-ethyl-5-hydroxymethyl-1,3-dioxane (A in formula 1 is a polyoxypropylene group composed of 5 oxypropylene units) A shrinkage reducing agent for a hydraulic cement composition comprising the compound of formula 1 in the case.
[0025]
Moreover, as embodiment of the hydraulic cement composition which concerns on this invention, following 9) is mentioned.
9) cement unit amount 320 kg / ^{m 3,} fine aggregates 800 kg / ^{m 3,} contain coarse aggregate 976kg / ^{m 3} and water 180 kg / ^{m 3,} and a polycarboxylic acid-based cement 100 parts by weight per cement dispersant The hydraulic cement composition according to any one of the present inventions of 0.15 parts by weight of a vinyl polymer salt, 0.0008 parts by weight of rosin soap as an air entraining agent and the above 1) to 8) as a shrinkage reducing agent Concrete comprising 2 parts by weight of a material shrinkage reducing agent.
[0026]
Hereinafter, examples and the like will be given in order to make the configuration and effects of the present invention more specific, but the present invention is not limited to the examples.
[0027]
【Example】
Test Category 1 (Synthesis of compounds represented by Formula 1 as shrinkage reducing agents for hydraulic cement compositions)
Examples 1 to 3
In a stainless steel autoclave, 731 g (5 mol) of 5-ethyl-5-hydroxymethyl-1,3-dioxane and 3.6 g of potassium hydroxide as a catalyst were added and dissolved while stirring. After the reaction system was completely purged with nitrogen, the temperature of the reaction system was raised to 130 ° C. While maintaining the temperature of the reaction system at 130 to 140 ° C., 440 g (10 mol) of ethylene oxide was sequentially injected under a pressurized condition of ^{2 to 4} kg / cm ² for 1 hour, followed by aging for 2 hours. To obtain a crude product. Alkali was removed from the crude product by adsorption filtration using a magnesium silicate-based adsorbent to obtain Compound P-1 as a shrinkage reducing agent for hydraulic cement composition. Similarly, compounds P-2 and P-3 as shrinkage reducing agents for hydraulic cement compositions were obtained.
[0028]
Examples 4 to 6
To a stainless steel autoclave, 731 g (5 mol) of 5-ethyl-5-hydroxymethyl-1,3-dioxane and 5.2 g of potassium hydroxide as a catalyst were added and dissolved while stirring. After the reaction system was completely purged with nitrogen, the temperature of the reaction system was raised to 130 ° C. While maintaining the temperature of the reaction system at 130 to 140 ° C., 440 g (10 mol) of ethylene oxide was sequentially injected under a pressurized condition of ^{2 to 4} kg / cm ² for 1 hour, followed by aging for 1 hour. did. Further, 580 g (10 mol) of propylene oxide was sequentially injected and subjected to an addition reaction for 1 hour, followed by aging for 2 hours to obtain a crude product. The crude product was subjected to the same adsorption filtration treatment as above to obtain Compound P-4 as a shrinkage reducing agent for hydraulic cement composition. Similarly, compounds P-5 and P-6 as shrinkage reducing agents for hydraulic cement compositions were obtained.
[0029]
Examples 7 and 8
Into a stainless steel autoclave, 731 g (5 mol) of 5-ethyl-5-hydroxymethyl-1,3-dioxane and 3.9 g of potassium hydroxide as a catalyst were added and dissolved while stirring. After the reaction system was completely purged with nitrogen, the temperature of the reaction system was raised to 130 ° C. While maintaining the temperature of the reaction system at 130 to 140 ° C., 580 g (10 mol) of propylene oxide was sequentially injected under a pressurized condition of ^{2 to 4} kg / cm ^{2 and} an addition reaction was performed for 1 hour. A crude product was obtained by aging for a while. The crude product was subjected to the same adsorption filtration treatment as described above to obtain Compound P-7 as a shrinkage reducing agent for hydraulic cement composition. Similarly, Compound P-8 as a shrinkage reducing agent for hydraulic cement composition was obtained.
[0030]
・ Comparative Examples 1-3
Compounds R-1 to R-3 as shrinkage reducing agents for hydraulic cement compositions were obtained in the same manner as the synthesis of compounds P-1 to P-8 of Examples 1-8. The contents of each compound synthesized above are summarized in Table 1.
[0031]
[Table 1]

[0032]
In Table 1,
R-4: 5-ethyl-5-hydroxymethyl-1,3-dioxane used as a raw material
Test category 2 (Preparation and evaluation of concrete)
Examples 9 to 19 and Comparative Examples 5 to 12 (Preparation of concrete)
Under the blending conditions described in Table 2, a 50 L pan-type forced kneader was mixed with ordinary Portland cement (specific gravity = 3.16, brain value 3300), fine aggregate (Oigawa Aquatic river sand, specific gravity = 2.58, FM = 2) .69) and coarse aggregate (Okazaki crushed stone, specific gravity = 2.68) were sequentially added and kneaded for 15 seconds. Next, in each case, a cement dispersant (a high-performance AE water reducing agent comprising a salt of a polycarboxylic acid vinyl polymer manufactured by Takemoto Yushi Co., Ltd.) so that the target slump is 21 ± 1 cm and the target entrainment air amount is 4-5% by volume. , Trade name Tupole HP-11), air entraining agent (AE agent manufactured by Takemoto Yushi Co., Ltd., trade name AE300) and compound as shrinkage reducing agent for hydraulic cement composition synthesized in Test Category 1 with water. And kneaded to prepare concrete. The amounts of compounds added as shrinkage reducing agents for hydraulic cement compositions are summarized in Table 3.
[0034]
[Table 2]

[0035]
-Evaluation of physical properties of concrete For each concrete prepared, the slump and entrained air amount immediately after mixing, the drying shrinkage rate, the freeze-thaw durability index, and the compressive strength were determined as follows, and the results are summarized in Table 3. .
[0036]
.. Slump: The concrete immediately after mixing was measured according to JIS-A1101.
.. Entrained air amount: Measured according to JIS-A1128 for concrete immediately after mixing.
-Drying shrinkage ratio: Based on JIS-A1129, the specimen of the age of 26 weeks preserve | saved under the humidity control of 20 degreeC x 60% RH was measured by the comparator method. It shows that shrinkage is so small that a numerical value is small.
.. Freeze-thaw durability index: Measured according to JIS-A1148, and a numerical value calculated by the durability index of ASTM-C666-75 is shown. This numerical value indicates that the maximum value is 100, and the closer to 100, the better the resistance to freezing and thawing.
Compressive strength: Measured at a material age of 28 days in accordance with JIS-A1108.
[0037]
[Table 3]

[0038]
In Table 3,
Amount of addition: part by weight of compound relative to 100 parts by weight of cement R-5: diethylene glycol mononormal butyl ether R-6: dipropylene glycol diethylene glycol mononormal butyl ether
【The invention's effect】
As apparent from the above, the present invention described above can sufficiently suppress the drying shrinkage of the cured product obtained from the prepared hydraulic cement composition, and at the same time, the cured product has sufficient resistance to freeze-thaw action. There is an effect that can be given.

Claims (5)

A shrinkage reducing agent for a hydraulic cement composition, comprising a compound represented by the following formula 1.
[Formula 1]

(In Equation 1,
A: a (poly) oxyethylene group composed of 1 to 15 oxyethylene units, a (poly) oxypropylene group composed of 1 to 10 oxypropylene units, or a total of 2 to 25 oxyethylene units A polyoxyalkylene group composed of oxypropylene units) The compound represented by Formula 1 is composed of a (poly) oxyethylene group in which A in Formula 1 is composed of 1 to 10 oxyethylene units or a total of 2 to 15 oxyethylene units and oxypropylene units. The shrinkage reducing agent for hydraulic cement composition according to claim 1, which is a polyoxyalkylene group. 3. The hydraulic cement composition according to claim 1, wherein the hydraulic cement composition contains cement, aggregate, cement dispersant, air entraining agent, shrinkage reducing agent, and water as a shrinkage reducing agent per 100 parts by weight of cement. A hydraulic cement composition comprising a shrinkage reducing agent for use in a proportion of 0.2 to 10 parts by weight. The hydraulic cement composition according to claim 3, wherein the hydraulic cement composition is concrete prepared so that the amount of entrained air immediately after mixing is 3 to 7% by volume. Furthermore, the hydraulic cement composition of Claim 4 which prepared the slump immediately after kneading to more than 18 cm.