Durability of Recycled Concrete after Reinforcing the Aggregates with Permeable Crystalline Materials

The utilization of recycled aggregate can significantly mitigate the extraction of natural sand and gravel. However, the practical application of recycled aggregate in engineering is impeded by its inherent characteristics, encompassing high water absorption, high crushing, and low apparent density. This study employed a soaking and air-drying method to enhance the strength of three types of aggregates with varying initial strengths by utilizing permeated crystalline materials. The durability of recycled aggregate concrete (RAC) was studied with three different aggregate replacement rates (0%, 50%, and 100%). The test results demonstrate that the slump, compressive strength, freeze resistance, and carbonation resistance of RAC exhibit a decreasing trend as the aggregate replacement rate increases. The freeze resistance and carbonation resistance of RAC are notably enhanced after incorporating permeated crystalline material. This study contributes to a sustainable and efficient solution for the treatment of construction waste, thereby enhancing the utilization rate of recycled concrete.