Mechanical performance of composite slabs with recycled concrete aggregates: the SARCOS project

The urgency to reduce the environmental impact of concrete structures is widely recognized, with the consumption of natural aggregates being a significant concern due to the need for new quarries. Recycled concrete aggregates (RCA) derived from construction and demolition waste offer a viable solution. Composite slabs, made of concrete over a steel sheet, present multiple benefits over traditional slabs, including faster construction, enhanced strength, and environ- mental advantages. This study examines the mechanical performance of 48 composite slabs with RCA replacement levels ranging from 0% to 100%, across three span lengths (2.4 m, 2.8 m, 3.2 m). Four-point bending tests were conducted, focusing on load-bearing capacity and interface bond strength. Results indicate that slabs with RCA demonstrate structural perfor- mance comparable to those without RCA, highlighting its potential as a sustainable construc- tion solution. This research provides insight into optimal RCA levels for composite slabs, balancing sustainability with high mechanical standards.