Energetics of cement hydration

Copeland et al. (C38) reviewed the energetics of cement hydration. After the first few days, the rate of heat liberation is too low for conduction calorimetry to be a practicable means of investigation, but the total amount of heat liberated after any desired time can be determined from the heat of solution in acid, which is compared with that of the unhydrated cement. Fig. 7.9 gives average results thus obtained for different US types of Portland cements. 

Using least squares regression analysis, the heat liberated at any given age was predicted from the potential phase composition by equations of the type 

In principle, it should be possible to calculate the heat of hydration from the quantitative phase compositions of the unreacted mix and of the paste, using standard enthalpies of formation. The sensitivity of such calculations to small errors in the latter data probably renders this approach unsatisfactory with existing data. 

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