Effects of waterborne epoxy resin on the mechanical properties and microstructure of slag cementing slurries

Abstract

The enhancement mechanism of epoxy resin on the physical properties of a slag solidified body with poor mechanical properties and susceptibility to cracking was investigated. Furthermore, the mechanical properties of an epoxy resin/slag cured body with varying resin contents and temperatures were studied experimentally. SEM, XRD, FTIR, and TG-DTG were used to test the structure and morphology of the epoxy resin/slag cured body. The results are as follows: (1) When the ratio of epoxy resin to curing agent is 10:3, the cured slag’s 7 days (7d) compressive and tensile strength at 50 °C are 65% and 52% higher, respectively, than the blank sample when the epoxy resin content is 15%. The compressive and tensile strength at 90 °C for seven days increased by 101% and 102%, respectively, compared to the blank sample. When epoxy resin content is 25%, the solidified slag's 7d compressive and tensile strength at 70 °C is 191% and 134% higher, respectively, than the blank sample. (2) Calcium silicate aluminate hydrate (C-A-S-H) is still the main hydration product of the composite, but there is less silica-magnesium hydrotalcite structure, which is different from the slag solidified body; (3) In the composite material, the three-dimensional network structure formed by epoxy resin curing is combined with the hydration products, and the polymer film fills the pores and cracks of the slag, improving the microstructure and mechanical properties of the slag. The results have theoretical significance for enhancing the physical properties of solidified slag and broadening its potential applications.