On the Mechanism of Hydration of Portland Cement with Active Center in Hydration Reaction Zhou Xianjia;Ye LiangyunThe hydration reaction of water on the surface of C_3S, β-C_2S, C_3A and C_(4A)F has been studiedby temperature programmed desorption (TPD). There are two kinds of absorption species, molecularstate and ionic state, of water on the surface in four single-minerals. That is, there exist two kinds ofabsorption active center in the single-minerals with water. It may be formed C-S-H on the activecenter of molecular state and C-H on the active center of ionic stute. The relative number of activecenter on C_3A, C_3S, C_4AF and β-C_2S is 100, 97.7, 69. 9 and 2.2 respectively. The activation energyof desorption (Ed) was obtained.Temperature programmed desorption;;Absorption species;;Absorption active center;;Activation energy of desorption