Effect of Admixture Additive on Properties of Polymer-modified Lightweight Cement Mortar

Redispersible polymer powder of vinyl acetate and versatate copolymer (VA/Voeva) used as admixture additive, is introduced to modify lightweight cement mortar with ground granulated blast furnace slag, quartz sand and expanded perlite as aggregates. The effect of the dosage of redispersible polymer powder of vinyl acetate and versatate on the compressive and flexural strengths was investigated in details. The ratio of compressive strength to flexural strength (sigma(c)/sigma(f)) of cement mortars varied with the variation of the dosage of redispersible polymer powder. Scanning electronic microscopy was used to investigate the internal structure of the polymer-modified lightweight cement mortar. The result showed that the toughness of the polymer-modified lightweight cement mortar was improved with the increase in the dosage of redispersible polymer powder, and the network membranous structure formed by the polymer attribute to the improvement of the toughness and flexural strengths.