Enhancing acid resistance of geopolymer concrete composites by utilising styrene-butadiene latex, nano-silica and micro-silica powder

The acid resistance of geopolymer binder, a promising alternative to ordinary Portland cement with clean technology option, needs detailed investigations for widespread use in different applications and severe acidic conditions. The aim of this work is to enhance acid resistance of geopolymer concretes (GPCs) by employing styrene-butadiene latex (SBL), nano-silica (NS) and micro-silica (MS) powders. The residual compressive strength, weight loss, visual appearance and microstructure properties of GPC samples were evaluated after exposed to hydrochloric acid (HCl) solutions with different concentrations (3%, 5% and 7%) for 90 and 180 days. The addivites increase residual compressive strength by preventing acid liquids to ingress the interior areas thanks to additional pozzolanic and filler effect leading to more compact and denser microstructure. Any apparent damage was not observed at the outer surface of GPC specimens.