JPH0220579B2 - - Google Patents
Info
- Publication number
- JPH0220579B2 JPH0220579B2 JP57140993A JP14099382A JPH0220579B2 JP H0220579 B2 JPH0220579 B2 JP H0220579B2 JP 57140993 A JP57140993 A JP 57140993A JP 14099382 A JP14099382 A JP 14099382A JP H0220579 B2 JPH0220579 B2 JP H0220579B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- weight
- dextrin
- water
- present
- 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
- 229920001353 Dextrin Polymers 0.000 claims description 24
- 239000004375 Dextrin Substances 0.000 claims description 24
- 235000019425 dextrin Nutrition 0.000 claims description 24
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 16
- 239000004568 cement Substances 0.000 claims description 15
- 238000006703 hydration reaction Methods 0.000 claims description 11
- 230000036571 hydration Effects 0.000 claims description 10
- 229920002472 Starch Polymers 0.000 claims description 4
- 239000008107 starch Substances 0.000 claims description 4
- 235000019698 starch Nutrition 0.000 claims description 4
- 239000003112 inhibitor Substances 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 2
- 230000000694 effects Effects 0.000 description 8
- 238000002474 experimental method Methods 0.000 description 7
- 239000004570 mortar (masonry) Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000011398 Portland cement Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 2
- 239000012153 distilled water Substances 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- RGHNJXZEOKUKBD-UHFFFAOYSA-N D-gluconic acid Natural products OCC(O)C(O)C(O)C(O)C(O)=O RGHNJXZEOKUKBD-UHFFFAOYSA-N 0.000 description 1
- RGHNJXZEOKUKBD-SQOUGZDYSA-N Gluconic acid Natural products OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C(O)=O RGHNJXZEOKUKBD-SQOUGZDYSA-N 0.000 description 1
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229920006328 Styrofoam Polymers 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000002255 enzymatic effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 239000000174 gluconic acid Substances 0.000 description 1
- 235000012208 gluconic acid Nutrition 0.000 description 1
- 239000008103 glucose Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 239000003340 retarding agent Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000008261 styrofoam Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Landscapes
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
Description
本発明は、モルタルやコンクリートの水和熱に
よる温度上昇を抑制するセメントの水和熱抑制
剤、詳しくは、特定製法によつて得られた特定の
水可溶分をもつデキストリンからなる、温度上昇
抑制効果を改善したセメントの水和熱抑制剤に関
する。
本発明において、デキストリンの水可溶分と
は、デキストリンを温度21℃又は60℃の蒸留水に
溶解した量を意味するものであり、具体的には、
試料デキストリン10ｇを200mlのメスフラスコに
入れ、温度21℃又は60℃の蒸留水150mlを加え、
その温度に１時間保持した後別しその液を蒸
発乾凅して得られたデキストリンを試料デキスト
リンに対する割合で示したものである。
近年、土木建築構造物の大型化が進み、マスコ
ンクリート工事が増加している。それにともな
い、セメントの水和による発熱とその蓄積が大き
くなつて、コンクリート温度が材令初期に急激に
上昇し、それが降下したときの応力が原因となつ
て、コンクリートにいわゆる熱ひびわれが発生す
る。
これを防止するには、温度21℃の水可溶分10〜
65重量％であるデキストリンを添加する方法が提
案されているが（特公昭57−261号公報）、まだ、
十分とはいえない。本発明者は、さらに検討を加
えた結果、温度21℃という低温における溶解性以
外に、高温における溶解性とそのデキストリンの
生産過程についても温度上昇抑制効果に重要な作
用を及ぼすことを見い出し、本発明を完成したも
のである。
すなわち、本発明は、デンプンに塩酸を加え加
熱分解して得られたものであつて、その水可溶分
が21℃で10〜50重量％、60℃で50〜100重量％で
あるデキストリンからなるセメントの水和熱抑制
剤である。
以下、詳しく本発明について説明すると、ま
ず、本発明において、デキストリンは、デンプン
に塩酸を加え、加熱分解して製造されるもの（以
下、塩酸法デキストリンという）に限定した。デ
キストリンは、通常、硝酸や塩酸などの希酸を加
え加熱分解するか、又は、デンプンの酵素分解や
グルコースの縮合によつて製造されるものである
が、これらの方法によつて得られたデキストリン
は、例え、その溶解性を適切にコントロールした
ものであつても、塩酸法デキストリンに比べて温
度上昇抑制効果が小さい。
また、本発明では、塩酸法デキストリンであつ
ても、その水可溶分が適切でないと十分な効果を
発揮しない。すなわち、温度21℃における水可溶
分が10〜50重量％で、しかも、温度60℃において
は50〜100重量％となる、つまり、常温では溶け
にくいが高温になると容易に溶けるようなデキス
トリンであることを要する。実施例で説明する通
り、温度21℃における水可溶分が10重量％未満の
ものであつては、デキストリンを添加しない場合
とほぼ同程度に温度上昇し、また、50重量％をこ
えるものであつて、水和反応が始まるまでの時間
延長には効果的であるが、その後に急激に反応
し、最高温度は、デキストリンを添加しないとき
よりも高くなることがある。いずれの場合にあつ
ても、温度上昇抑制効果はない。温度21℃におけ
る好ましい水可溶分は20〜40重量％である。一
方、温度60℃における水可溶分は少くとも50重量
％であることを要し、好ましくは60〜90重量％で
ある。50重量％未満のものであつては、水和熱に
よる温度が高くなつても水可溶分が少ないため、
温度上昇抑制効果は小さくなる。
本発明に係るデキストリンの添加量は、セメン
トに対し0.05〜10重量％であり、0.05重量％未満
の添加では、温度上昇抑制効果が小さく、また、
10重量％をこえる添加量では、強度に悪影響を与
えることがある。とくに好ましい添加量は0.1〜
２重量％である。セメントとしては、普通、早
強、超早強、中庸熱、白色の各種のポルトランド
セメント、シリカやフライアツシユ、高炉スラグ
などを配合した混合セメント、ならびに膨張セメ
ント、急硬セメントなど、どのようなセメントで
あつてもよい。
以上、説明したように、本発明は、特定の溶解
性を有する塩酸法デキストリンの少量をセメント
に含有させたものであり、それによつて、セメン
トの水和熱にもとづく温度上昇を著しく抑制する
ことができるという効果がある。併わせて、減水
性と長期材令における強度発現が良好となる利点
がある。
なお、本発明に係るデキストリンは、他の混和
剤である空気連行剤、減水剤、遅延剤等との組合
わせにおいても使用でき、そのことにより、本発
明の効果が失われるものではない。
以下、実施例をあげてさらに説明する。
実施例 １
普通ポルトランドセメント100重量部、相模川
産川砂５mm下200重量部、第１表の方法によつて
得られた種々の水可溶分を有するデキストリンを
0.4重量部、水セメント比42％、練り上り温度20
℃に調整したモルタルを高さ30cm、内径13cm、厚
さ10cmの発泡スチロール製円筒容器に約４入
れ、20℃恒温室中で養生したときのモルタル中心
部の温度を熱電対で自動的に測定した。その結果
を第２表に示す。実験No.２は本発明例、実験No.１
及びNo.３〜No.５は比較例である。
又、同一モルタルで成形した5φ×10cmの供試
体を20℃水中養生したときの圧縮強度を測定し
た。その結果を第３表に示す。
The present invention is a cement hydration heat suppressant that suppresses the temperature rise due to the hydration heat of mortar and concrete, and more specifically, a cement hydration heat suppressant that suppresses the temperature rise due to the hydration heat of mortar and concrete. This invention relates to a heat of hydration inhibitor for cement with improved inhibitory effect. In the present invention, the water-soluble content of dextrin means the amount of dextrin dissolved in distilled water at a temperature of 21°C or 60°C, and specifically,
Put 10g of sample dextrin into a 200ml volumetric flask, add 150ml of distilled water at a temperature of 21°C or 60°C,
The dextrin obtained by maintaining the temperature for 1 hour and then evaporating the liquid to dryness is expressed as a percentage of the sample dextrin. In recent years, civil engineering and building structures have become larger, and mass concrete work is increasing. As a result, the heat generated by cement hydration and its accumulation increases, causing the concrete temperature to rise rapidly in the early stages of the material's life, and when this temperature drops, the stress causes so-called thermal cracks to occur in the concrete. . To prevent this, the water soluble content at a temperature of 21℃ is 10~
A method of adding 65% by weight of dextrin has been proposed (Japanese Patent Publication No. 57-261), but still
Not enough. As a result of further investigation, the present inventor discovered that in addition to the solubility at a low temperature of 21°C, the solubility at high temperatures and the dextrin production process also have an important effect on the temperature rise suppressing effect. It is a completed invention. That is, the present invention is made from dextrin, which is obtained by adding hydrochloric acid to starch and decomposing it by heating, and whose water-soluble content is 10 to 50% by weight at 21°C and 50 to 100% by weight at 60°C. It is a heat of hydration inhibitor for cement. The present invention will be described in detail below. First, in the present invention, dextrin is limited to one produced by adding hydrochloric acid to starch and thermally decomposing it (hereinafter referred to as hydrochloric acid method dextrin). Dextrins are usually produced by adding dilute acids such as nitric acid or hydrochloric acid and decomposing them with heat, or by enzymatic decomposition of starch or condensation of glucose. Dextrins obtained by these methods Even if its solubility is appropriately controlled, the effect of suppressing temperature rise is smaller than that of hydrochloric acid dextrin. Further, in the present invention, even if the hydrochloric acid dextrin is used, sufficient effects will not be exhibited unless the water-soluble content is appropriate. In other words, the water-soluble content at a temperature of 21℃ is 10 to 50% by weight, and at a temperature of 60℃ it is 50 to 100% by weight.In other words, it is a dextrin that is difficult to dissolve at room temperature but easily melts at high temperatures. It requires something. As explained in the examples, if the water-soluble content at a temperature of 21°C is less than 10% by weight, the temperature will rise to almost the same degree as when no dextrin is added, and if it exceeds 50% by weight. In some cases, it is effective in extending the time until the hydration reaction starts, but then the reaction occurs rapidly and the maximum temperature may be higher than when no dextrin is added. In either case, there is no effect of suppressing temperature rise. The preferred water soluble content at a temperature of 21°C is 20 to 40% by weight. On the other hand, the water-soluble content at a temperature of 60° C. must be at least 50% by weight, preferably 60 to 90% by weight. If it is less than 50% by weight, even if the temperature due to the heat of hydration increases, the water-soluble content will be small.
The temperature rise suppression effect becomes smaller. The amount of dextrin added according to the present invention is 0.05 to 10% by weight based on the cement. If less than 0.05% by weight is added, the effect of suppressing temperature rise is small, and
If the amount added exceeds 10% by weight, the strength may be adversely affected. Particularly preferable addition amount is 0.1~
It is 2% by weight. Any type of cement can be used, including ordinary, early-strength, ultra-early-strength, medium-heat, and white Portland cements, mixed cements containing silica, fly ash, blast furnace slag, etc., as well as expansion cements and rapid-hardening cements. It may be hot. As explained above, the present invention involves cement containing a small amount of hydrochloric acid dextrin having a specific solubility, thereby significantly suppressing the temperature rise due to the heat of hydration of cement. It has the effect of being able to. In addition, it has the advantage of good water-reducing properties and good strength development over a long period of wood age. Note that the dextrin according to the present invention can also be used in combination with other admixtures such as air entraining agents, water reducing agents, retarding agents, etc., and the effects of the present invention are not thereby lost. The present invention will be further explained below with reference to Examples. Example 1 100 parts by weight of ordinary Portland cement, 200 parts by weight of river sand from the Sagami River, 5 mm thick, and dextrins containing various water-soluble components obtained by the method shown in Table 1.
0.4 parts by weight, water-cement ratio 42%, kneading temperature 20
Approximately 4 pieces of mortar adjusted to ℃ were placed in a cylindrical foam container with a height of 30 cm, an inner diameter of 13 cm, and a thickness of 10 cm, and the temperature at the center of the mortar was automatically measured using a thermocouple when it was cured in a constant temperature room at 20 ℃. . The results are shown in Table 2. Experiment No. 2 is an example of the present invention, Experiment No. 1
and No. 3 to No. 5 are comparative examples. In addition, the compressive strength of a 5φ x 10cm specimen molded with the same mortar was measured after it was cured in water at 20°C. The results are shown in Table 3.
【表】【table】
【表】【table】
【表】
実施例 ２
普通ポルトランドセメント100重量部、粗骨材
として相模川産川砂利352重量部と、細骨材とし
て相模川産川砂５mm下255重量部、水セメント比
56％の配合で、本発明に係るデキストリンを添加
して、練り上り温度20℃に調整したコンクリート
とし、これを厚さ10cmの発泡スチロールで四面断
熱し、二面放熱とした50×50×50cmの鉄製型わく
に入れ、20℃恒温室中で養生したときのコンクリ
ート中心部の温度を熱電対で自動的に測定した。
なお、参考のためにグルコン酸及び混和剤無添
加の場合について、同様に試験を行つた。その結
果を第４表に示す。実験No.７は本発明例、実験No.
６及びNo.８は参考例である。[Table] Example 2 100 parts by weight of ordinary Portland cement, 352 parts by weight of river gravel from the Sagami River as coarse aggregate, 255 parts by weight of river sand from the Sagami River 5 mm below as fine aggregate, water-cement ratio
The dextrin according to the present invention was added to make concrete with a mixing ratio of 56%, and the mixing temperature was adjusted to 20℃.This was insulated on all sides with 10cm thick Styrofoam and heat radiated on two sides. The temperature at the center of the concrete was automatically measured using a thermocouple when it was placed in a steel mold and cured in a constant temperature room at 20°C. For reference, a similar test was conducted without the addition of gluconic acid or admixture. The results are shown in Table 4. Experiment No. 7 is an example of the present invention, Experiment No.
6 and No. 8 are reference examples.
【表】
実施例 ３
本発明に係るデキストリンを用い、その添加量
を変化させた以外は、実施例１と同様な実験を行
つた。
モルタル中心部の最高温度と圧縮強度を第５表
に示す。
実験No.10〜No.16は本発明例、実験No.９及びNo.17
は比較例である。[Table] Example 3 An experiment similar to Example 1 was conducted except that the dextrin according to the present invention was used and the amount added was varied. Table 5 shows the maximum temperature and compressive strength at the center of the mortar. Experiment No. 10 to No. 16 are examples of the present invention, Experiment No. 9 and No. 17
is a comparative example.
【表】【table】
Claims (1)
ものであつて、その水可溶分が温度21℃で10〜50
重量％、温度60℃で50〜100重量％であるデキス
トリンからなるセメントの水和熱抑制剤。1 It is obtained by adding hydrochloric acid to starch and decomposing it by heating, and its water-soluble content is 10 to 50% at a temperature of 21℃.
Cement heat of hydration inhibitor consisting of dextrin, which is 50-100% by weight at a temperature of 60℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14099382A JPS5930743A (en) | 1982-08-16 | 1982-08-16 | Cement composition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14099382A JPS5930743A (en) | 1982-08-16 | 1982-08-16 | Cement composition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5930743A JPS5930743A (en) | 1984-02-18 |
| JPH0220579B2 true JPH0220579B2 (en) | 1990-05-09 |
Family
ID=15281652
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14099382A Granted JPS5930743A (en) | 1982-08-16 | 1982-08-16 | Cement composition |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5930743A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62207747A (en) * | 1986-03-04 | 1987-09-12 | 大成建設株式会社 | Manufacture of underwater concrete |
| DE69839164T2 (en) | 1997-11-26 | 2009-03-05 | Nippon Steel Corp. | Resin coating composition for metal sheets, resin sheets to which they are applied, resin-coated metal sheet and metal containers |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55121935A (en) * | 1979-03-06 | 1980-09-19 | Denki Kagaku Kogyo Kk | Cement additive |
| JPS57261A (en) * | 1980-05-31 | 1982-01-05 | Nat Jutaku Kenzai | Apparatus for mounting upgrade beam |
-
1982
- 1982-08-16 JP JP14099382A patent/JPS5930743A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55121935A (en) * | 1979-03-06 | 1980-09-19 | Denki Kagaku Kogyo Kk | Cement additive |
| JPS57261A (en) * | 1980-05-31 | 1982-01-05 | Nat Jutaku Kenzai | Apparatus for mounting upgrade beam |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5930743A (en) | 1984-02-18 |
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