Physico-mechanical properties of cement mortar-polymer composites

摘要

Earlier investigations of polymer-impregnated concrete tried mainly to increase the quantity of absorbed and polymerised monomer because this gave a greater decreae in the original porosity of concrete and a subsequent improvement in physicomechanical properties. Recent research showed the possibility of obtaining with a very compact concrete, of relative low porosity, a compound material with high performances after impregnation, through containing a low amount of polymer. In this investigation the hardened cement mortar pastes were prepared by mixing of the cement-sand dry mixture, in a weight ratio of 1: 3, with water (water/cement ratio = 0.4). After stopping of hydration at each hydration time interval, the dried mortar specimens were subjected to monomer impregnation, then irradiated using γ-ray for various doses. The monomers used for impregnation are methyl methacrylate (MMA), acrylonitrile (AN) and mixtures of MMA and AN. All of the physicochemical and mechanical properties of the polymer impregnated mortar composites as well as the unimpregnated mortar specimens (control samples) were fully discussed and related as much as possible to the changes in the pore structure of the hardened mortar specimens and the nature of each polymer formed within the pore system of the polymer impregnated mortar composites.