Premix polymer cement concrete

On the basis of previous work, three monomers, viz, methyl methacrylate, butyl methacrylate and styrene, were selected for extensive investigations as premix additives for concrete. For comparison purposes, polymer impregnation with methyl methacrylate and butyl methacrylate was investigated. Styrene was not used because of difficulties in polymerisation. The results indicated that only methyl methacrylate dispersed well in the fresh concrete. It also increased workability substantially. The strength of all concretes containing premix additives were less than the strength of the control series. Shrinkage values were increased relative to the control series and in the case of the polymethyl methacrylate series this increase was substantial. The strength of the impregnated series was higher than the controls, as would be expected. The impregnated concrete exhibited negative shrinkage in a drying environment, a finding consistent with previously reported information on the creep of polymer impregnated concrete.