Effect of Admixtures on Heat of Hydration of Fresh Cement Huang Xuehui Zheng Jian Ma Baoguo Assoc. Prof., School of Materials Science and Engineering, WUT, Wuhan 430070, China.The effects of different kinds of mineral and chemical admixtures on the heat of hydration of the fresh cement were investigated by means of measurement of the heat of hydration and the principles of reducing or raising the heat of hydration were probed too in this paper. The results show that the admixtures of both flyash and mineral can obviously reduce the heat of hydration and temperature rise of the fresh cement. The admixtures, such as the water reducing agent of FDN 5 and the retarding agent of the molasses can also reduce the heat of hydration and temperature rise of the fresh cement and delay the advent of the thermal spike. The early strength agent of Na 2SO 4 can increase the heat of hydration and temperature raise, meanwhile it advances the advent of the thermal spike. The effect of the air entraining agent of rosin on the heat of hydration and temperature rise isn't obvious.admixtures;\ heat of hydration;\ high performance concrete