Effect of sulfuric acid on cementitious composites containing ethylene-vinyl acetate and styrene-butadiene rubber

This study focuses on the influence of ethylene-vinyl acetate (EVA) and styrene-butadiene rubber (SBR) on the sulfuric acid resistance of ordinary Portland cement (OPC)-sulfoaluminate cement (SAC) repair mortar. Mortars were exposed to sulfuric acid solution for 60 or 180 days. The degradation kinetics, mineralogical as well as microstructural changes of these samples were analyzed. The results showed that EVA and SBR decreased the mechanical properties of OPC-SAC repair mortar but improved the mortar resistance to sulfuric acid attack. Both EVA and SBR could homogenize and refine the pore structure, reduce the number of connected and open pores, and fill the invasion channels of H+ and SO42 . The dual three-dimensional network structure formed by polymers in OPC-SAC mortar could delay the propagation of microcracks and limit the residual hydration and corrosion products around the core, forming a protective barrier.