Flexural Behavior of RC Beams Made with Recycled Aggregates Under 12-Month Long Term Loading

Abstract

In the present era of infrastructure development, demolishing waste management poses serious problems, particularly in urban centers. Vast development requires huge amounts of conventional concrete aggregates resulting in serious environmental problems. Therefore, efforts are carried out in utilizing demolishing waste, particularly demolishing concrete as coarse aggregates used in new concrete. This article presents laboratory investigations of flexural behavior of reinforced concrete beams made with partial replacement of natural coarse aggregates with coarse aggregates from demolished concrete under 12-month long-term loading. Two batches of beams were cast and cured for 28 days. In the first batch three RC beams with partial replacement of natural coarse aggregates were cast, while in the second batch 6 RC beams with all-natural coarse aggregates were prepared. Out of these six beams three beams were tested under short-term loading to determine maximum load. 50% of this load was used as sustained load on the remaining all beams. The beams were mounted on purpose made frames and deflection, strain, and cracking were recorded on daily basis. After the elapse of the defined time the beams were tested under central point load until failure. Result comparison shows a 4.96% increase in deflection and 2.33% reduction in peak load. Based on the results of this study it is concluded that demolished concrete as coarse aggregates in new concrete shows reasonably good performance under 12-month long-term loading.