A study on the effect of microspheres on the freeze-thaw resistance of EPS concrete

This study investigated the influence of microbead dosages (0, 5, 10, 15, and 20%) on the frost resistance of expanded polystyrene (EPS) concrete. Five groups of EPS concrete specimens were prepared and subjected to rapid freeze-thaw tests. The freeze-thaw deterioration of EPS concrete was assessed using macroscopic indicators, including mass loss, strength loss, and dynamic elastic modulus loss. The underlying deterioration mechanism was revealed through the analysis of the EPS particle-matrix interface. A concrete damage plasticity model of EPS concrete based on damage mechanics theory was established. The results indicate that the addition of microbeads increased the strength of EPS concrete by 38-53%, reduced the strength attenuation after freeze-thaw damage by 8.1%, and improved the frost resistance level by 10-60 grades. The optimal dosage of microbeads is 15% of the cementitious material. The interfacial transition zone gaps in EPS concrete with added microbeads after freeze-thaw cycles are smaller, contributing to a more complete hydration reaction. The freeze-thaw damage model established in this study accurately reflects the freeze-thaw damage law of EPS concrete and provides a reference for studying the mechanical properties of EPS concrete under freeze-thaw cycles. The research findings of this study can enhance the strength and service life of EPS concrete, expanding its application scope as a structural material. The study provides valuable insights for future research and engineering applications related to the frost resistance of EPS concrete.