Damage prediction and long-term cost performance analysis of glass fiber recycled concrete under freeze-thaw cycles

Abstract

This paper establishes a freeze-thaw cycle damage model by analyzing the changes in mass, relative dynamic elastic modulus and compressive strength of glass fibers (0 %, 0.5 %, 1.0 %, and 1.5 %) recycled concrete after the freeze-thaw cycle (0, 50, 100, and 150) tests. Meanwhile, the antifreeze life of concrete is predicted based on the Weibull distribution model. The study show that glass fiber can reduce the deterioration of recycled concrete specimen surfaces result from frozen-thaw environment. After 150 freeze-thaw cycles, the specimens with 0.5 %, 1.0 %, and 1.5 % glass fiber content showed a reduction in mass loss of 0.405 %, 1.100 %, and 0.725 %, and an increase in compressive strength of 8.19 %, 21.35 %, and 17.79 %, respectively, when compared with the specimens without glass fiber. Fiber can provide tension when recycled concrete is compressed, thus improving compressive strength, and the optimum glass fiber content is 1.0 %. After 150 freeze-thaw cycles, the freeze-thaw damage of recycled concrete specimens with 1.0 % glass fiber content was the smallest. Compared with that before freeze-thaw, the mass of the specimens only decreased by 2.128 %, and the compressive strength decreased by 35.2 %. Finally, the long-term cost-effectiveness of Recycled Aggregate Concrete (RAC) is analyzed based on the predicted life, and the performance optimization and economic benefits are comprehensively considered. Therefore, the appropriate volumetric admixture of glass fiber can be selected according to the actual situation in different regions, considering the cost-effectiveness of glass fiber recycled concrete to provide suggestions for related research.