PURPOSE: To obtain a retarder of heat generation by hydration capable of suppressing the heat generation by the hydration of cement and preventing the crack of a hardened concrete caused by the heat generation by using a granular body composed of hardly water-soluble portion of dextrin as a main component. ;CONSTITUTION: The retarder of heat generation by hydration of cement comprises primarily the granular body composed of the hardly water-soluble portion after removing the easily water-soluble component in the dextrin. The retarder of heat generation by hydration of cement is slowly dissolved under an alkaline condition in the cement at the time of adding to the cement to use. Then, after being in contact with water, a retarding material is hardly eluted during the leading period till the start of the hydration reaction of the cement and the elusion of the retarding material proceeds in the accelerating period to raise the temp. due to the hydration of the cement. As a result, the problem to retard the starting time of the hydration reaction is not generated and on the other hand, in the accelerating period of the hydration reaction, the temp. rises by the heat generation by the hydration of the cement. As a result, the retarding action is increased with an increase in the eluting quantity of the retarding material and the heat generation by the hydration is effectively suppressed.;COPYRIGHT: (C)1995,JPO
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