Latex-modified Engineered Cementitious Composites (L-ECC)

Abstract

This paper reports the influence of polymer latex on the fresh and the hardened properties of engineered cementitious composites (ECC), a unique strain-hardening cement-based material featuring extreme tensile strain capacity of 3-5%. Ethylene-vinyl acetate (EVA) dispersible polymer powder was employed in the synthesis of latex-modified ECC (L-ECC). The effects of EVA dosage on viscosity, air content, compressive strength, direct tensile stress-strain relation, four point bending behavior, and microstructure of L-ECC were reported. It was found that the addition of EVA increases the viscosity and the air content of fresh mixture. While the compressive and the tensile strength of L-ECC decrease with increasing EVA dosage, the tensile strain capacity and the toughness of the resulting material show significant enhancement. This is attributed to the change of microstructure as evidenced by the SEM images when EVA is used in the mixture.