Performance of Mortar Containing Recycled Fine Aggregates From Fire-Exposed Concrete

Concrete structures are inevitably exposed to fire, and the resulting waste is typically recycled in the same manner as ordinary concrete debris. Therefore, evaluating the performance of post-fire concrete waste and its derived materials is essential for promoting the broader use of recycled aggregates. In this study, intact concrete specimens were heated to 600°C, 800°C, and 1000°C to simulate the fire damage. The fire-exposed concrete was crushed into fine aggregates and incorporated into cement mortar to evaluate their effects on drying shrinkage and mechanical strength. The results indicated that the drying shrinkage of the mortar increased to different extents, depending on the replacement ratio and heating temperature of the recycled fine aggregates. Meanwhile, the loss of mechanical strength increased with higher replacement ratios and heating temperatures. Overall, this study provided evaluations of post-fire concrete waste for engineering applications, contributing to sustainable construction material management.