Analysis of fire resistance of ethylene-vinyl acetate polymer calcium sulfoaluminate cement mortars

This research focuses on enhancing the fire resistance of cement mortars by incorporating ethylene-vinyl acetate (EVA) polymer. It aims to assess how EVA improves the mortar’s performance when exposed to high temperatures and fire. The expected benefits include increased durability and enhanced safety under fire conditions through polymer modification. To investigate this, calcium sulfoaluminate cement mortars with varying EVA contents were subjected to direct fire exposure up to 700°C, following a detailed experimental plan to analyze their thermomechanical behavior after testing. The findings reveal that some samples experienced explosive reactions upon exposure to fire. Notably, the incorporation of EVA significantly enhanced both compressive and flexural strengths after direct fire exposure, with mortars containing 2 and 3% EVA achieving impressive compressive strengths of 11.55 and 13.82 MPa, respectively; the flexural strength peaked at approximately 4.5 MPa with 3% EVA. Thermal analyses indicated pronounced improvements in insulation properties for EVA concentrations between 1 and 3%, evidenced by reduced thermal conductivity and increased specific heat, highlighting the energy efficiency of these modified mortars, a vital consideration for sustainable construction. Additionally, mercury intrusion porosimetry testing showed that the optimal porosity of 29.92% was achieved with 1% EVA, while further increases to 2 and 3% led to diminishing returns. Thus, determining the optimal percentage of EVA is essential, as EVA modifications present a promising and sustainable alternative to conventional practices in cement mortars.