Investigation of Waste Glass Sand Concrete Durability under Alternating Dry–Wet and Freeze–Thaw Conditions

Freeze–thaw durability is a critical concern in concrete applications, particularly in harsh environmental conditions. To address this issue and promote the recycling of waste resources simultaneously, various solutions have been explored. We prepared concrete specimens with different proportions of waste glass sand (WGS) instead of river sand. It was used to evaluate the effect of waste glass sand on the durability of concrete. The proportions used were 0%, 10%, 30%, and 50%. The concrete specimens underwent a standardized 28-day curing period. Subsequently, the freeze–thaw cycle test was conducted at intervals of 0, 15, 30, and 45 dry–wet cycles until the specimens failed. Ultrasonic wave analysis was employed to examine the waveforms, and the internal phase and chemical composition of the concrete were characterized using a scanning electron microscope and a spectral analyzer. The freeze–thaw cycle process of WGS concrete was numerically simulated using Abaqus (version 2023) finite-element software, and the results were compared with the test results. The results led to the following observations: (1) As the dosage of WGS increases, the deterioration appearance of the concrete surface subjected to dry–wet and freeze–thaw cycles gradually improves, resulting in a more intact appearance of the specimens. (2) Under identical cycles of erosion conditions, the relative dynamic modulus of elasticity of concrete significantly increases with the rising proportion of WGS fine aggregate replacement. Additionally, there is an observable trend of reduced mass loss rate. (3) Ultrasonic and microscopic testing and numerical simulation prove effective in verifying that the inclusion of WGS can ameliorate the adverse effects of dry–wet and freeze–thaw cycles.