Physico-chemical parameters determining hydration and particle interactions during the setting of silicate cements

Abstract Hydration of tricalcium silicate (Ca 3 SiO 5 ), the pure phase used as a model of the portland cements, is the chemical process leading to the formation of hydrates, while setting is a definite time event corresponding to the change of the paste from the soft to the hard state. Setting results from interactions between anhydrous or very partially hydrated particles. The analysis of these interactions leads to the identification of two fundamental steps: the coagulation of cement grains during the first minutes following the mixing and the rigidification of the coagulated structure which arises simultaneously with the acceleration of the calcium silicate hydrates (CSH) formation. …