Study on the effect of WER and EVA on the performance and microstructure of cement mortars for a prefabricated residential floor

Abstract

In this study, cement mortars were modified with ethylene-co-vinyl acetate (EVA) powder and water-based epoxy resin (WER) emulsion. This study aimed to investigate the effect of the content of the two polymers on the mechanical properties, abrasion resistance, and toughness of the mortar and to relate these properties to the microstructure of the mortar. We combined IPP(a combination of Stereo Light Microscopy and Image-Pro Plus image processing software) and the mercury intrusion porosimetry (MIP) to analyze the microscopic pore structure of polymer modified mortars. The microstructure of polymer modified mortars was studied by scanning electron microscopy (SEM). The results show that the use of alternating wet and dry curing regimes helps to improve the toughness of the modified mortar. Under this curing regime, the maximum flexural strength of the polymer modified mortar was 14.32 MPa and the maximum compressive strength was 90.52 MPa. The addition of polymer significantly improved the abrasion and impact resistance of the cement mortar, with a 28% reduction in abrasion volume from 116 mm3 to 83 mm3 and a 36% increase in impact strength from 13.92 J/cm2 to 18.97 J/cm2. Both polymers have the effect of filling capillary pores in the mortar, but there is a difference in the effect on large-size pores at high dosing levels. This work contributes to an in-depth understanding of the role of polymers in improving the performance of cement mortars, which enables rational development of polymer modified cementitious materials for prefabricated residential floors.