Research on Freeze-Thaw Cycle Performance of High Ductility Cement-based Composites: Mechanism, Evolution and Life Prediction.

Abstract

As a novel construction material with exceptional tensile toughness and crack control capability, the durability of Engineered Cementitious Composites (ECC) in cold environments is of significant importance. This paper systematically investigates the performance evolution and mechanisms of ECC under freeze-thaw cycles. The research indicates that freeze-thaw cycles lead to a reduction in the peak stress of ECC, coarsening of the internal pore structure, and weakening of the fiber-matrix interface. However, the bridging action of fibers can effectively inhibit the propagation of macro-cracks. After 300 freeze-thaw cycles, the mass loss rate of PVA fiber-reinforced ECC can be controlled within 2.5%, and its dynamic elastic modulus retention rate is significantly higher than that of ordinary concrete. Compounding PE-ECC with FRP mesh further enhances frost resistance, with the maximum load-carrying capacity increased by up to 67.3%. This study also establishes a damage model based on the Wiener process and a prediction method integrating multi-scale surface structure recognition, providing a theoretical basis and design reference for the engineering application of ECC in cold regions. The results demonstrate that ECC exhibits excellent durability under freeze-thaw conditions. Through material optimization and composite reinforcement techniques, the service life of engineering structures in cold regions can be significantly extended.