Effect of Waterborne Epoxy Resin on the Shrinkage and Mechanical Properties of Geopolymer Material

Due to the drawbacks of high shrinkage and lots of cracks, geopolymer material shows poor brittle performance. The waterborne epoxy resin is added to address these issues for geopolymers. The shrinkage and mechanical properties of modified geopolymers with aqueous epoxy resin at 10 wt %, 20 wt %, and 30 wt % are investigated in this paper. Furthermore, SEM is used to evaluate the effect of resin on the hydration process of geopolymers. The results show that the shrinkage and toughness of modified geopolymers with waterborne epoxy resin are reduced and improved, respectively. The shrinkage of the geopolymer with 10 wt% epoxy resin is reduced by 25% in 28 days compared to that of the control, with the flexural strength increasing by 17.5%. Simultaneously, the bonding strength at the concrete interface is higher than 2.0 MPa. This paper describes an efficient method to optimize the brittleness of geopolymers.