Abstract: Aiming at the problems of concrete maintenance in the engineering construction in permafrost regions, by 10%, 20% and 30% of the ground granulated blast furnace slag(GGBS) and fly ash(FA) replacing cement content, the hydration heat of cement pastes with 0.38 water cement pastes at different ages was tested under the condition of constant temperature curing at-3 ℃, and the hydration degree of cement was calculated.The influence of age and mineral admixtures on the hydration degree of cement was analyzed, and the calculation model of the hydration degree of cement was established.The results show that the-3 ℃ constant temperature curing, mineral admixture replacing cement, the hydration degree of cement paste can be reduced, FA to reduce the degree of hydration value than GGBS.With the increase of the age, the effect of mineral admixtures on the hydration degree of cement is gradually decreased with the increase of the age of the same mineral admixture.At the same time, with the increase of mineral admixture, the effect of mineral admixtures on the hydration degree of cement is gradually increasing.The cement hydration degree were mixed with 15% FA and GGBS were calculated by using the model, compared with the measured values, the deviation is less, higher prediction accuracy.

Key words: mineral admixture;cement hydration;hydration degree;calculation model;age