Experimental study on flexural properties of steel fiber recycled brick concrete composite slab

Abstract In response to the low utilization rate of green recycled resources in concrete composite slabs, which makes it difficult to meet the core connotation of green and sustainable development in construction, recycled bricks were used as coarse aggregate concrete, and polypropylene fibers and steel fibers were selected, respectively. Based on the indexes of the fiber content, water–cement ratio, substitution rate, and other indicators, the optimal process combination of fiber‐recycled brick concrete was determined by orthogonal test design method, range, and variance analysis to optimize the material composition and ratio. Based on these findings, a composite slab was proposed with a prefabricated layer made of steel fiber recycled brick concrete and a post‐cast composite layer made of ordinary concrete. Static bending tests were conducted on composite slabs (1 one‐way slab specimen and 1 two‐way slab specimen) and compared to ordinary concrete specimens, analyzing bearing capacity, load–deflection curves, load–steel strain curves, and cooperative working performance. The results show that the prefabricated bottom plates and composite slabs made of recycled brick concrete exhibited similar bending failure processes to those made of ordinary concrete, passing through elastic, elastic–plastic, and failure phases, with high bearing capacity and good cooperative working performance.