Effect of different fiber reinforcements on the strength and acid attack resistance of alkali-activated concrete

Abstract

The study analyzes the effect of steel, polyvinyl alcohol (PVA), polypropylene (PP), and glass fiber reinforcements in alkali-activated concrete (AAC) by conducting various mechanical strength tests. The fiber dosages are maintained at 0.1-0.3% by volume of AAC. Furthermore, the study evaluates the effect of acidic exposures on the strength of fiber-reinforced alkali-activated concrete (FRAAC) by immersing the samples in 10% v/v solutions of HCl. H2SO4 and HNO3 for 28 days. The findings revealed that fiber additions improved the compressive and flexural strength properties by up to 13% and 27%, respectively, while the modulus of elasticity improved significantly by up to 52%. Acid attack tests on AAC specimens demonstrated H2SO4 to be highly detrimental to the mechanical and chemical properties of AACs. The strength loss in FRAAC after acidic exposures was up to 50% lesser as compared to the plain mix. Glass-FRAACs were found to be highly resistant to acid attack, whereas steel-FRAACs had a relatively lesser resistance. These findings were further validated by the SEM micrographs, XRD, and FTIR analyses, which depicted the changes in the microstructure of the specimens subjected to acidic environments. Overall, fiber reinforcements improve the mechanical and durability properties of AACs.