JPH07172893A - Retarder of heat generation by hydration of cement - Google Patents
Retarder of heat generation by hydration of cementInfo
- Publication number
- JPH07172893A JPH07172893A JP5345687A JP34568793A JPH07172893A JP H07172893 A JPH07172893 A JP H07172893A JP 5345687 A JP5345687 A JP 5345687A JP 34568793 A JP34568793 A JP 34568793A JP H07172893 A JPH07172893 A JP H07172893A
- Authority
- JP
- Japan
- Prior art keywords
- cement
- hydration
- heat generation
- oxidized starch
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
- C04B24/24—Macromolecular compounds
- C04B24/38—Polysaccharides or derivatives thereof
-
- 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
- C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
- C04B2103/0068—Ingredients with a function or property not provided for elsewhere in C04B2103/00
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、セメントの水和に伴う
発熱を抑制し、もって、発熱による硬化コンクリートの
ひび割れ（以下、温度ひび割れという）を防止するため
のセメントの水和発熱抑制剤に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement hydration heat generation inhibitor for suppressing heat generation due to hydration of cement and for preventing cracking of hardened concrete due to heat generation (hereinafter referred to as temperature cracking). .
【０００２】[0002]
【従来の技術】温度ひび割れが発生する主な理由は、セ
メントの水和発熱によってコンクリートの内部と外部の
間に温度差が生じ、この温度差に起因する応力が、硬化
コンクリートの引張強度を上回るからである。従って、
セメントの水和発熱を抑制し、コンクリート内・外部間
の温度差を小さくすることは、温度ひび割れを防止する
うえで有効な手段となる。このような考えに基づき、従
来、次の物質からなるセメントの水和発熱抑制剤が提案
されている。 ａ）尿素（特開昭62-223048 号公報） ｂ）５〜６０℃に融点または転移点をもつ蓄熱物質（特
開平3-69542 号公報） ｃ）冷水可溶分５〜９０重量％のデキストリン（特開昭
55-75950号公報） ｄ）加水分解性タンニン（特開昭63-117941 号公報）2. Description of the Related Art The main reason for temperature cracks is that the hydration heat of cement causes a temperature difference between the inside and outside of concrete, and the stress caused by this temperature difference exceeds the tensile strength of hardened concrete. Because. Therefore,
Suppressing the heat of hydration of cement and reducing the temperature difference between the inside and outside of concrete is an effective means for preventing temperature cracks. Based on such an idea, conventionally, a hydration exothermic inhibitor for cement composed of the following substances has been proposed. a) Urea (JP-A-62-223048) b) Heat storage substance having a melting point or transition point at 5 to 60 ° C (JP-A-3-69542) c) Dextrin having a cold water-soluble content of 5 to 90% by weight (JP Sho
55-75950) d) Hydrolyzable tannin (Japanese Patent Laid-Open No. 63-117941)
【０００３】上記物質がセメントの水和発熱を抑制する
機構は次のように考えられる。すなわち、上記ａ，ｂは
物質自体の吸熱作用を利用するものであり、コンクリー
ト中で尿素は加水分解する際に熱を吸収し、また上記蓄
熱物質は融解または相転移の際に潜熱を吸収することに
より水和発熱を抑制する。一方、上記ｃ，ｄはセメント
の水和反応を遅延することにより水和発熱を抑制するも
のであり、デキストリンは粉体の溶解によりデキストリ
ン分子を放出し、また、加水分解性タンニンは加水分解
によりタンニン分子を放出し、コンクリートの液相中に
放出されたこれらの物質がセメントの水和反応を遅延さ
せて水和発熱を抑制する。The mechanism by which the above substances suppress the heat of hydration of cement is considered as follows. That is, the above a and b utilize the endothermic action of the substance itself, urea absorbs heat when hydrolyzing in concrete, and the heat storing substance absorbs latent heat when melting or phase transition. This suppresses the heat of hydration. On the other hand, the above c and d are for suppressing the heat of hydration by delaying the hydration reaction of cement, dextrin releases dextrin molecules by the dissolution of powder, and hydrolyzable tannin is hydrolyzed by hydrolysis. These substances released tannin molecules, and these substances released in the liquid phase of concrete delay the hydration reaction of cement and suppress the heat of hydration.
【０００４】[0004]
【発明の解決課題】しかしながら、上記尿素および蓄熱
物質は、吸熱量が添加量に依存するので、有意な効果を
得ようとするとコンクリート中にこれらの物質を多量に
添加しなければならない。ところが、コンクリート中に
尿素を多量に添加すると、加水分解により多量の炭酸お
よびアンモニアが生成し、これらがコンクリートの中性
化を促進する原因や悪臭の原因となる。また、上記蓄熱
物質は高価であり、大幅なコスト高になるなど、それぞ
れ実用上の問題を有している。一方、上記デキストリン
および加水分解性タンニンは、比較的少量の添加で水和
発熱を抑制する（以下、抑制作用という）ことができる
が、同時にセメントの水和開始時期も遅らせ（以下、遅
延作用という）、これらの作用が不可分の関係にある。
従って、特に、コンクリートが夏場のような高温度下に
置かれると、遅延作用が著しくなり、型枠の脱型時期の
延長や、ブリージング量の増大などの問題が生じ易い。
本発明は、従来のセメントの水和発熱抑制剤における、
かかる実情に鑑みてなされたもので、少量の添加でも大
きな発熱抑制効果を発揮し、かつ高温度下でも遅延作用
に起因する上記問題を生じないセメントの水和発熱抑制
剤を提供することを目的とする。However, since the endothermic amount of the above-mentioned urea and heat storage substances depends on the addition amount, it is necessary to add a large amount of these substances to concrete in order to obtain a significant effect. However, when a large amount of urea is added to concrete, a large amount of carbonic acid and ammonia are generated by hydrolysis, and these cause the promotion of carbonation of concrete and the offensive odor. In addition, each of the heat storage materials is expensive and has a large cost, and each has practical problems. On the other hand, the dextrin and the hydrolyzable tannin can suppress the heat of hydration by the addition of a relatively small amount (hereinafter, referred to as an inhibitory effect), but at the same time delay the hydration initiation timing of the cement (hereinafter, referred to as a delayed effect). ), These effects are inseparable.
Therefore, especially when the concrete is placed under a high temperature such as in summer, the delay action becomes remarkable, and problems such as extension of the mold release time and increase of the breathing amount are likely to occur.
The present invention relates to a conventional cement hydration exothermic inhibitor,
In view of such circumstances, an object is to provide a cement hydration exothermic inhibitor that exerts a large exothermic inhibitory effect even with a small amount of addition, and does not cause the above problems due to a retarding action even at high temperature. And
【０００５】[0005]
【課題の解決手段】この目的達成のため、本発明者は、
セメントの水和反応に関与する水和発熱抑制剤につい
て、さらに詳細にその機構を研究した結果、下記の知見
を得、この知見に基づいて、遅延作用に起因する問題を
生じないセメントの水和発熱抑制剤を完成するに至っ
た。一般に、セメントの水和は、接水後数時間の水和反
応が始まるまでの時期（以下、誘導期という）を経た
後、水和反応が活発な時期（以下、加速期という）に移
行することが知られている。本発明者は上記水和発熱抑
制剤から放出される遅延物質が誘導期において遅延作用
を示し、加速期において抑制作用を示すことを見出し
た。これをデキストリンについてみると、上記ｃの冷水
可溶分を５〜９０重量％含有するデキストリンとは、温
度２１℃の水１５０ｍｌに、これを１０ｇ加え、温度を
２０〜２３℃に１時間保持した場合、水に溶解するデキ
ストリンを５〜９０重量％含むものであり、これをコン
クリートに添加すると、数時間に及ぶ誘導期に、コンク
リートの液相中にデキストリン分子が溶出し、これが水
和開始時期を遅らせる。特に、コンクリートの打ち込み
温度や環境温度が高い場合、溶出するデキストリン量は
さらに多くなり、遅延作用が増大して誘導期が長くなる
ので脱型時期が大幅に遅れる。また、上記ｄの加水分解
性タンニンも、セメントの練り混ぜ直後から、加水分解
反応によりタンニン分子を放出し、同様の現象を示す。
上記知見に基づき、本発明に係るセメントの水和発熱抑
制剤は、遅延物質の放出時期を調整したものであって、
水和反応の誘導期においては遅延物質を殆ど放出せず、
加速期に至って遅延物質を放出する性質を有する物質を
主成分としたものである。To achieve this object, the present inventor has
Regarding the hydration heat suppressor involved in the hydration reaction of cement, the mechanism was studied in more detail, and the following findings were obtained. Based on this finding, hydration of cement that does not cause problems due to delayed action We have completed a heat release inhibitor. Generally, the hydration of cement shifts to a period when the hydration reaction is active (hereinafter referred to as an acceleration period) after a period (hereinafter referred to as an induction period) until the hydration reaction starts for several hours after contact with water. It is known. The present inventor has found that the delay substance released from the hydration exothermic suppressant exhibits a delaying action in the induction period and an inhibitory action in the acceleration period. Looking at this dextrin, the dextrin containing 5 to 90% by weight of the cold water-soluble component of c was added to 150 ml of water at a temperature of 21 ° C., 10 g of this was added, and the temperature was kept at 20 to 23 ° C. for 1 hour. In this case, the water-soluble dextrin is contained in an amount of 5 to 90% by weight, and when this is added to concrete, dextrin molecules are eluted in the liquid phase of the concrete during the induction period of several hours, which is the hydration start time. Delay. In particular, when the driving temperature of the concrete and the environmental temperature are high, the amount of dextrin that elutes further increases, the delaying action increases and the induction period becomes longer, so the demolding time is greatly delayed. Further, the hydrolyzable tannin of the above d also exhibits the same phenomenon by releasing the tannin molecule by the hydrolysis reaction immediately after the mixing of the cement.
Based on the above findings, the hydration exothermic inhibitor for cement according to the present invention is one in which the release timing of the delay substance is adjusted,
In the induction period of the hydration reaction, the retarder is hardly released,
The main component is a substance having a property of releasing a retarding substance in the acceleration period.
【０００６】[0006]
【発明の構成】具体的には、以下の構成からなるセメン
トの水和発熱抑制剤である。 （１） アルファー化した酸化デンプンの粉粒体を主成
分とする、セメントの水和発熱抑制剤。 （２） アルファー化した酸化デンプンの粉粒体を主成
分とし、弱アルカリ性下で徐々に溶解する上記(1) のセ
メントの水和発熱抑制剤。 （３） 上記粉粒体の粒度が０．１〜２０００μm であ
る上記(1) または(2)のセメントの水和発熱抑制剤。Concretely, the present invention is a cement hydration exothermic inhibitor having the following constitution. (1) A hydration exothermic suppressor for cement, which comprises, as a main component, powdered granules of oxidized starch that have been converted into alpha. (2) The hydration exothermic inhibitor for cement as described in (1) above, which contains alfa-oxidized starch powder and granules as a main component and gradually dissolves under weak alkaline. (3) The hydration heat inhibiting agent for cement according to (1) or (2), wherein the particle size of the powder is 0.1 to 2000 μm.
【０００７】[0007]
【具体的な説明】本発明で云うアルファー化とは、酸化
デンプンを溶剤の存在下で糊化温度以上に加熱すること
をいう。溶剤としては、水、ジメチルスルホキシド、ジ
メチルホルムアミド等の１種、または２種以上を混合し
たものを使用することができる。酸化デンプンを、上記
溶剤中に懸濁して加熱するか、または加熱した溶剤に投
入して糊化する。糊化後、乾燥して粉砕し、またはスプ
レードライによって粉粒体にする。その他の方法によっ
て粉粒体にして良い。もっとも、風乾状態の酸化デンプ
ンを、密封容器内で糊化温度以上に加熱することによ
り、乾燥、造粒工程を経ることなく、アルファー化した
酸化デンプンの粉粒体を得ることもできる。これらの粉
粒体はアルファー化により、酸化デンプンの結晶部分が
非結晶化され、水に膨潤後、溶解する。[Detailed Description] The term "pregelatinization" as used in the present invention means that oxidized starch is heated to a gelatinization temperature or higher in the presence of a solvent. As the solvent, one kind of water, dimethyl sulfoxide, dimethylformamide or the like, or a mixture of two or more kinds can be used. The oxidized starch is suspended in the above solvent and heated, or put into a heated solvent to gelatinize. After gelatinization, it is dried and pulverized, or spray-dried to give powder. Granules may be formed by other methods. However, by heating the air-dried oxidized starch to a gelatinization temperature or higher in a hermetically sealed container, it is possible to obtain a pregelatinized oxidized starch powder or granules without a drying and granulating step. These powders are pregelatinized to decrystallize the crystalline part of the oxidized starch, swell in water and dissolve.
【０００８】酸化デンプンは、通常、デンプンに水と酸
化剤を加え、糊化温度より低い温度でスラリー状態で反
応させるか、または糊化温度より高い温度で糊化状態で
反応させて製造することができる。スラリー状態で反応
させて製造した酸化デンプンは結晶部分が存在し、水に
溶解しないため、水和発熱抑制効果を示さない。ところ
が、本発明者は、スラリー状態で反応させて製造した酸
化デンプンをアルファー化することにより、酸化デンプ
ンが水に膨潤・溶解するようになり、その結果、水和発
熱抑制効果を示すこと、また、糊化状態で反応させて製
造した酸化デンプンは、製造過程でアルファー化される
ため、このままで水和発熱抑制効果を示すことを見出し
た。Oxidized starch is usually produced by adding water and an oxidizing agent to starch and reacting it in a slurry state at a temperature lower than the gelatinization temperature or in a gelatinization state at a temperature higher than the gelatinization temperature. You can Oxidized starch produced by reacting in a slurry state does not exhibit a hydration exotherm suppressing effect because it has a crystalline portion and does not dissolve in water. However, the present inventor, by gelatinizing the oxidized starch produced by reacting in a slurry state, the oxidized starch becomes swelled / dissolved in water, and as a result, it exhibits a heat of hydration suppression, and It was found that the oxidized starch produced by the reaction in the gelatinized state is pregelatinized in the production process, and thus exhibits the hydration exothermic suppression effect as it is.
【０００９】酸化剤は公知のものを使用でき、例えば、
次亜塩素酸ナトリウム、次亜塩素酸カルシウム、さらし
粉、過マンガン酸カリ、重クロム酸カリ、過ヨウ素酸、
硝酸、過硫酸アンモニウム、過硫酸ナトリウム、過硫酸
カリ、過酸化水素等が用いられ、必要なら、硫酸銅、硫
酸鉄等の触媒を使用してもよい。これら酸化剤の仕込み
量は、デンプン１００重量部に対し、２〜８０重量部が
好適である。２重量部未満では酸化デンプンの増粘性が
大きく、好ましくない。酸化剤が８０重量部を越える
と、低分子酸化生成物が多くなり、セメントに添加した
ときに水和反応の遅延が顕著になる。As the oxidizing agent, known ones can be used, for example,
Sodium hypochlorite, calcium hypochlorite, bleaching powder, potassium permanganate, potassium dichromate, periodate,
Nitric acid, ammonium persulfate, sodium persulfate, potassium persulfate, hydrogen peroxide and the like are used, and if necessary, a catalyst such as copper sulfate and iron sulfate may be used. The charging amount of these oxidizing agents is preferably 2 to 80 parts by weight with respect to 100 parts by weight of starch. If it is less than 2 parts by weight, the thickening of the oxidized starch is large, which is not preferable. When the amount of the oxidant exceeds 80 parts by weight, the amount of low molecular weight oxidation products increases, and when added to cement, the hydration reaction is significantly delayed.
【００１０】アルファー化された酸化デンプンは粉粒体
として使用することが必要である。粉粒体の粒度は０．
１〜２０００μm が適当であり、１〜１０００μm が好
ましい。０．１μm 未満では、セメントに添加した際、
水和反応の誘導期から遅延物質の溶出が生じ易くなるの
で好ましくない。また粒径が２０００μm を越えると、
加速期における溶出が不十分になる。Pregelatinized oxidized starch needs to be used as a granulate. The particle size of the granular material is 0.
1 to 2000 μm is suitable, and 1 to 1000 μm is preferable. Below 0.1 μm, when added to cement,
It is not preferable because the delayed substance is likely to be eluted from the induction period of the hydration reaction. If the particle size exceeds 2000 μm,
Dissolution becomes insufficient during the acceleration period.
【００１１】アルファー化した酸化デンプンのセメント
に対する添加量は、セメント１００重量部に対して、
０．０５〜５重量部が適当である。添加量が０．０５重
量部未満では、水和発熱抑制効果は不十分であり、５重
量部を越える添加量では、強度発現が遅くなる。添加方
法は制限されず、例えば、セメントに乾燥状態で直接に
添加するか、あるいは、コンクリートの混練時に、上記
粉粒体を混練水に分散させて使用する。また、使用され
るセメントの種類も制限されず、例えば、普通ポルトラ
ンドセメント、中庸熱ポルトランドセメント、高炉セメ
ント、フライアッシュセメント、高ビーライトセメン
ト、早強セメント、膨脹セメントなど公知のセメントに
対して使用することができる。The amount of pregelatinized oxidized starch added to cement is 100 parts by weight of cement.
0.05 to 5 parts by weight is suitable. If the amount added is less than 0.05 parts by weight, the effect of suppressing heat of hydration is insufficient, and if the amount added exceeds 5 parts by weight, strength development becomes slow. The addition method is not limited, and for example, it is directly added to cement in a dry state, or the above-mentioned powdery particles are dispersed in kneading water when kneading concrete. Also, the type of cement used is not limited, for example, ordinary Portland cement, moderate heat Portland cement, blast furnace cement, fly ash cement, high belite cement, early-strength cement, expansion cement used for known cement can do.
【００１２】さらに、本発明に係るセメントの水和発熱
抑制剤は、ＡＥ剤、減水剤、ＡＥ減水剤、高性能減水
剤、流動化剤、収縮低減剤、凝結促進剤、防水剤、防錆
剤などの公知のコンクリート混和剤と併用することがで
きる。Further, the hydration heat generation inhibitor for cement according to the present invention is an AE agent, a water reducing agent, an AE water reducing agent, a high performance water reducing agent, a fluidizing agent, a shrinkage reducing agent, a setting accelerator, a waterproofing agent, an anticorrosive agent. It can be used in combination with a known concrete admixture such as an agent.
【００１３】本発明に係るセメントの水和発熱抑制剤は
セメントに添加して使用した場合、セメント中の弱アル
カリ性下で徐々に溶解するので、接水後、セメントの水
和反応開始までの誘導期には遅延物質が殆ど溶出せず、
セメントの水和発熱により温度が上昇する加速期におい
て遅延物質の溶出が進む。このため、水和反応の開始時
期を遅らせる問題がなく、他方、水和反応の加速期に
は、セメントの水和発熱により温度が上昇するため、遅
延物質の溶出量が多くなるので抑制作用が増大し、効果
的に水和発熱が抑制される。When the cement hydration exothermic inhibitor according to the present invention is used by adding it to the cement, it gradually dissolves in the cement under weak alkalinity, so induction after the contact with water until the initiation of the hydration reaction of the cement. In the period, the delay substance hardly elutes,
During the acceleration period when the temperature rises due to the heat of hydration of the cement, the delay substance elutes. Therefore, there is no problem of delaying the start time of the hydration reaction. On the other hand, during the acceleration phase of the hydration reaction, the temperature rises due to the heat of hydration of the cement, and the elution amount of the retarding substance increases, so the inhibitory action is The heat of hydration is effectively suppressed.
【００１４】[0014]
【発明の効果】以上のように、本発明に係るセメントの
水和発熱抑制剤は、少量の添加量でもセメントの水和発
熱を効果的に抑制でき、温度ひび割れなどの問題を確実
に防止することができる。しかも、高温下での施工にお
いても、水和反応の誘導期が長引かず、また長期材令に
おけるコンクリート強度に悪影響を及ぼすこともない。INDUSTRIAL APPLICABILITY As described above, the cement hydration heat generation inhibitor according to the present invention can effectively suppress the heat of hydration of cement even with a small addition amount, and reliably prevent problems such as temperature cracking. be able to. Moreover, even in the case of construction under high temperature, the induction period of the hydration reaction is not prolonged, and the concrete strength in a long-term age is not adversely affected.
【００１５】[0015]
【実施例および比較例】本発明の実施例を比較例と共に
以下に示す。なお、本実施例は例示であり、本発明の範
囲を限定するものではない。 製造例１ 水 300ｇに、次亜塩素酸ナトリウム10ｇとデンプン 100
ｇを加え、撹拌してスラリーにし、水酸化ナトリウムで
スラリーをpH９に調整しながら、糊化温度以下の30℃で
３時間撹拌し反応させた。反応後、スラリーを吸引ろ過
し、固形分は水洗し乾燥させた。次に、この酸化デンプ
ンを２群に分け、一方の酸化デンプン30ｇに水 180ｇを
加え、加熱撹拌して90℃に昇温し、この温度を15分間保
持して糊化した。糊液を乾燥後、乳鉢で粉砕、分級し
て、１〜 100μm のアルファー化した酸化デンプンの粉
粒体を得た。また、他方の酸化デンプン30ｇは、そのま
ま乳鉢で粉砕、分級して、１〜 100μm のアルファー化
しない酸化デンプンの粉粒体を得た。これを比較例に供
した。EXAMPLES AND COMPARATIVE EXAMPLES Examples of the present invention are shown below together with comparative examples. It should be noted that the present embodiment is merely an example and does not limit the scope of the present invention. Production Example 1 300 g of water, 10 g of sodium hypochlorite and 100 starch
g was added, and the mixture was stirred to make a slurry, and while the pH of the slurry was adjusted to 9 with sodium hydroxide, the mixture was stirred and reacted at 30 ° C. below the gelatinization temperature for 3 hours. After the reaction, the slurry was suction filtered, and the solid content was washed with water and dried. Next, this oxidized starch was divided into two groups, 180 g of water was added to 30 g of one oxidized starch, heated and stirred to raise the temperature to 90 ° C., and this temperature was maintained for 15 minutes to gelatinize. After the paste solution was dried, it was pulverized and classified in a mortar to obtain powdered granules of 1-100 μm of pregelatinized oxidized starch. On the other hand, 30 g of the other oxidized starch was crushed and classified as it was in a mortar to obtain 1 to 100 μm powdered particles of oxidized starch which were not pregelatinized. This was used as a comparative example.
【００１６】製造例２ 水2000ｇに、デンプン 100ｇを加え、加熱撹拌して糊化
温度以上の90℃に昇温し、この温度を15分間保持して糊
化した。次に、この糊液に、硫酸銅0.07ｇ、31％過酸化
水素水40ｇを加え、 100℃で30分間撹拌しながら反応さ
せた。反応後、反応液をスプレードライヤーで乾燥し、
造粒して、 0.1〜40μm のアルファー化した酸化デンプ
ンの粉粒体を得た。Production Example 2 To 2000 g of water, 100 g of starch was added, heated and stirred to raise the temperature to 90 ° C., which is higher than the gelatinization temperature, and kept this temperature for 15 minutes for gelatinization. Next, 0.07 g of copper sulfate and 40 g of 31% hydrogen peroxide solution were added to this paste solution, and the mixture was reacted at 100 ° C. for 30 minutes while stirring. After the reaction, dry the reaction solution with a spray dryer,
Granulation was carried out to obtain granules of 0.1-40 μm pregelatinized oxidized starch.
【００１７】実施例１〜４ 普通ポルトランドセメント 520ｇ、豊浦標準砂1040ｇ、
水 338ｇの JISモルタルに、セメント 100重量部に対
し、製造例１で得たアルファー化した酸化デンプンの粉
粒体を、おのおの 0.6重量部（3.12ｇ）、 0.8重量部
（4.16ｇ）加えて練り混ぜ、また製造例２で得たアルフ
ァー化した酸化デンプンの粉粒体を、おのおの 0.4重量
部（2.08ｇ）、 0.6重量部（2.08ｇ）加えて練り混ぜ、
それぞれ実施例１、実施例２、実施例３、および実施例
４として、モルタルの圧縮強度および温度を測定した。
圧縮強度は、モルタルを4 ×4 ×16cmに成形し、水中養
生して材令 7日および28日で測定した。また、温度の測
定方法は、練り上がったモルタルを全量、直径8.5cm、
高さ24cmのポリエチレン製の袋に詰め、この袋を内径10
cm、高さ28.5cmのステンレス製デュワー瓶内に挿入し、
熱電対を通したコルクで蓋をして、モルタルの中心部の
温度を自動的に測定した。上記の練り混ぜ、成形、水中
養生および温度測定は全て、30℃の恒温室内で行なっ
た。Examples 1 to 4 Ordinary Portland cement 520 g, Toyoura standard sand 1040 g,
To 338 g water of JIS mortar, 0.6 parts by weight (3.12 g) and 0.8 parts by weight (4.16 g) of the pregelatinized oxidized starch granules obtained in Production Example 1 were added to 100 parts by weight of cement and kneaded. In addition, 0.4 parts by weight (2.08 g) and 0.6 parts by weight (2.08 g) of the powdered granules of pregelatinized oxidized starch obtained in Production Example 2 were added and kneaded.
The mortar compressive strength and temperature were measured as Example 1, Example 2, Example 3, and Example 4, respectively.
The compressive strength was measured by molding mortar into 4 × 4 × 16 cm, curing in water, and aging 7 and 28 days. Also, the temperature measurement method, the total amount of kneaded mortar, diameter 8.5 cm,
Packed in a polyethylene bag with a height of 24 cm, this bag has an inner diameter of 10
cm, height 28.5 cm, and insert into a stainless steel Dewar bottle,
The temperature at the center of the mortar was automatically measured by covering with a cork through a thermocouple. The above kneading, molding, curing in water and temperature measurement were all carried out in a thermostatic chamber at 30 ° C.
【００１８】比較例１〜３ 実施例１〜４で用いた JISモルタルに、無添加のまま、
またはセメント 100重量部に対して、製造例１のアルフ
ァー化しない酸化デンプンを 0.8重量部（4.16ｇ）加え
て練り混ぜ、また冷水可溶分50重量％のデキストリンを
0.4重量部（2.08ｇ）加えて練り混ぜ、それぞれを比較
例１、比較例２、比較例３とし、実施例１〜４と同一の
方法および条件でモルタルの圧縮強度および温度を測定
した。上記実施例および比較例の圧縮強度の測定結果を
表１に示し、また温度の測定結果を図１に示した。Comparative Examples 1 to 3 JIS mortar used in Examples 1 to 4 was added without addition.
Alternatively, to 100 parts by weight of cement, 0.8 parts by weight (4.16 g) of non-pregelatinized oxidized starch of Production Example 1 was added and mixed, and dextrin having a cold water-soluble content of 50% by weight was added.
0.4 parts by weight (2.08 g) was added and kneaded to obtain Comparative Example 1, Comparative Example 2 and Comparative Example 3, and the compressive strength and temperature of the mortar were measured by the same method and conditions as in Examples 1 to 4. Table 1 shows the measurement results of the compressive strength of the above Examples and Comparative Examples, and FIG. 1 shows the measurement results of the temperature.
【００１９】図１に示すように、実施例１〜４のモルタ
ルの最高温度は何れも比較例１および２よりも低く、顕
著な水和発熱抑制効果を発揮していることが分かる。一
方、比較例２のアルファー化しない酸化デンプンを用い
たものは、無添加の場合と変わらず、水和発熱抑制効果
がない。また、従来のデキストリンを添加した比較例３
は、実施例３と同量の添加量でも、材令４０時間経過後
にはモルタルの温度が急激に上昇し、実施例２〜４を越
える温度になる。これは、従来のデキストリンからなる
抑制剤は、水に対する可溶分の量が多く、水和反応の誘
導期にその大部分が溶出するため、加速期の水和発熱を
抑制する効果が低下するからである。これに対して、本
発明のアルファー化した酸化デンプンの粉粒体からなる
抑制剤は、酸化デンプンがアルファー化によって、可溶
化されているものの、水和反応誘導期の溶出量は少な
く、加速期において主に溶出するので、効果的に水和発
熱を抑制することができる。また、表１に示すように、
実施例１〜４のモルタルの２８日材令強度は比較例１〜
３よりも高く、長期材令強度に対する悪影響も全くな
い。As shown in FIG. 1, the maximum temperatures of the mortars of Examples 1 to 4 are lower than those of Comparative Examples 1 and 2, and it is clear that the mortar exothermic suppression effect is remarkable. On the other hand, the case of using the oxidized starch which is not pregelatinized in Comparative Example 2 is not different from the case of no addition and has no hydration exothermic suppression effect. In addition, Comparative Example 3 in which conventional dextrin was added
In the case of the same amount as in Example 3, the temperature of the mortar rises sharply after 40 hours of age, reaching a temperature exceeding Examples 2 to 4. This is because the conventional inhibitor composed of dextrin has a large amount of soluble content in water and most of it is eluted during the induction period of the hydration reaction, so the effect of suppressing the heat of hydration during the acceleration period is reduced. Because. On the other hand, the inhibitor comprising the pregelatinized oxidized starch granules of the present invention shows that although the oxidized starch is solubilized by pregelatinization, the elution amount during the hydration reaction induction period is small and the accelerated period Since it mainly elutes in, it is possible to effectively suppress the heat of hydration. In addition, as shown in Table 1,
The 28-day-old strength of the mortars of Examples 1 to 4 is Comparative Example 1 to
It is higher than 3 and has no adverse effect on long-term strength.
【００２０】[0020]
【表１】 [Table 1]
【図１】実施例および比較例におけるモルタル温度の経
時変化を示すグラフ。FIG. 1 is a graph showing changes with time in mortar temperature in Examples and Comparative Examples.
Claims (3)
を主成分とする、セメントの水和発熱抑制剤。1. A hydration exothermic inhibitor for cement, which comprises, as a main component, powdered granules of oxidized starch that has been alpharized.
を主成分とし、弱アルカリ性下で徐々に溶解する請求項
１のセメントの水和発熱抑制剤。2. The hydration exothermic suppressor for cement according to claim 1, which comprises, as a main component, a powdered granular material of oxidized starch which has been alpharized, and which is gradually dissolved under weak alkaline.
m である請求項１または２のセメントの水和発熱抑制
剤。3. The particle size of the powder or granular material is 0.1 to 2000 μm.
The hydration exothermic suppressor for cement according to claim 1 or 2, which is m 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34568793A JP3346007B2 (en) | 1993-12-22 | 1993-12-22 | Hydration heat inhibitor for cement |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34568793A JP3346007B2 (en) | 1993-12-22 | 1993-12-22 | Hydration heat inhibitor for cement |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07172893A true JPH07172893A (en) | 1995-07-11 |
| JP3346007B2 JP3346007B2 (en) | 2002-11-18 |
Family
ID=18378289
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34568793A Expired - Fee Related JP3346007B2 (en) | 1993-12-22 | 1993-12-22 | Hydration heat inhibitor for cement |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3346007B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100322856B1 (en) * | 1999-06-30 | 2002-02-09 | 노재연 | Retarder for Gypsum Plaster and Cement |
| JP2003112957A (en) * | 2001-10-03 | 2003-04-18 | Denki Kagaku Kogyo Kk | Cement admixture, and cement composition |
| CN104609767A (en) * | 2015-02-05 | 2015-05-13 | 江苏苏博特新材料股份有限公司 | Cement hydration rate regulating material as well as preparation method and application of cement hydration rate regulating material |
| CN104628297A (en) * | 2015-02-05 | 2015-05-20 | 江苏苏博特新材料股份有限公司 | Cement hydration rate regulating material as well as preparation method and application thereof |
| US9376648B2 (en) | 2008-04-07 | 2016-06-28 | The Procter & Gamble Company | Foam manipulation compositions containing fine particles |
| CN109721272A (en) * | 2019-01-03 | 2019-05-07 | 河海大学 | A kind of magnesia retarder based on multi-vitamins, combined oxidation magnesium and application |
| WO2022122690A1 (en) * | 2020-12-11 | 2022-06-16 | Sika Technology Ag | Cementitious compositions comprising oxidatively degraded polysaccharide as water reducing agents |
-
1993
- 1993-12-22 JP JP34568793A patent/JP3346007B2/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100322856B1 (en) * | 1999-06-30 | 2002-02-09 | 노재연 | Retarder for Gypsum Plaster and Cement |
| JP2003112957A (en) * | 2001-10-03 | 2003-04-18 | Denki Kagaku Kogyo Kk | Cement admixture, and cement composition |
| US9376648B2 (en) | 2008-04-07 | 2016-06-28 | The Procter & Gamble Company | Foam manipulation compositions containing fine particles |
| CN104609767A (en) * | 2015-02-05 | 2015-05-13 | 江苏苏博特新材料股份有限公司 | Cement hydration rate regulating material as well as preparation method and application of cement hydration rate regulating material |
| CN104628297A (en) * | 2015-02-05 | 2015-05-20 | 江苏苏博特新材料股份有限公司 | Cement hydration rate regulating material as well as preparation method and application thereof |
| CN109721272A (en) * | 2019-01-03 | 2019-05-07 | 河海大学 | A kind of magnesia retarder based on multi-vitamins, combined oxidation magnesium and application |
| WO2022122690A1 (en) * | 2020-12-11 | 2022-06-16 | Sika Technology Ag | Cementitious compositions comprising oxidatively degraded polysaccharide as water reducing agents |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3346007B2 (en) | 2002-11-18 |
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