Mechanical properties of high porosity cement-based foam materials modified by EVA

Polymer ethylene vinyl acetate copolymer (EVA) modified high porosity (>90%) cement-based foam materials (HPECFM) were prepared by mechanical mixing air-entraining method. The influence of EVA on the mechanical properties of HPECFM was studied. The results showed that there was a direct correlation between the mechanical properties and EVA content. The maximum compressive strength 248 kPa was obtained when the ratio of EVA polymer to cement by weight (P/C) was 0.1. The impact toughness of EVA modified foam materials was increased with the rising of P/C. The impact toughness would be increased by 142.3% from 6.64 to 16.09 N m when the P/C varied from 0 to 0.33. The formed EVA polymeric film in the foam materials was observed by scanning electron microscopy (SEM). With the formation of EVA polymeric film, the matrix character of the foam materials would be changed from being brittle to flexible. Thus, the cement-based foam materials with excellent property of dissipating impact energy was obtained. This materials should be explored because of its simple fabrication process and good impact resistance properties.