Effect of rice husk ash on mechanical properties of rubber doped geopolymer recycled concrete

Abstract

Combining waste with building materials can effectively improve resource utilization and protect the environment.The inclusion of waste rubber particles in geopolymer recycled concrete can enhance its brittleness, but it also significantly reduces its mechanical properties This study aims to address this issue by modifying the waste rubber particles and incorporating agricultural waste rice husk ash. The experimental study focused on investigating the impact of Span-40 on the surface of waste rubber particles. Various properties such as compressive strength, flexural strength, and splitting tensile strength of geopolymer recycled concrete were evaluated using different dosages of modified waste rubber particles (0 %, 5 %, 10 %, and 15 %) along with varying single dosages of RHA/silica fume (SF) (0 %, 5 %, 10 %, and 15 %). The microstructure of the reclaimed concrete was analyzed using XRD and SEM. The findings indicate that the improvement in compressive strength of Span-40 modified rubber particle polymer recycled concrete increases with higher rubber particle incorporation ratio,curing 28d increased by about 8 %. Furthermore, the addition of RHA effectively enhances the mechanical properties of the reclaimed concrete, with the optimal effect observed at a 5 % RHA content,curing 28d increased by about 5 %.