Heat of hydration

Chemical reaction between water and cement compounds is known as hydration . Druing hydration of the cement , sufficient heat is generated . The process of heat generation is quite rapid in the initial phase of the setting but its rate diminiseh with the passage of time . Special care has to be taken to dissipate this heat otherwise mass concrete works are likely to developed cracks . For mass concrte works low heat cement should be used . heat of hydration for low heat cement should be as follows . This recommendation is based on IS: 4031 -1968 .

  After 7 days not more than 65 calories per gram and after 28 days not more than 75 calories per gram of cement .

  All the physical requirement of cement are given in Table 15.3 as per the recommendations of IS : 269 - 1967 .