Resource Sustainability Initiative: A Study on Usability of Recycled Coarse Aggregate in Concrete Making

Abstract

This research targets at providing insights on how coarse aggregate prepared from recycled concrete differs from normal coarse aggregate. The recycled coarse aggregate in this context is considered only if it comes from demolished concrete waste; construction waste has been kept out of the scope of the study. For this research, the recycled coarse aggregate was collected from Pasakha industrial dump yard and was manually crushed to the required size. The study aims at checking the feasibility of using recycled aggregate in concrete making. Aggregate tests were first conducted in the college laboratory to check whether the recycled aggregate met the basic strength and quality requirements as per standards. Tests on natural (normal) coarse aggregate were also conducted as reference or control tests. After obtaining satisfactory results from the aggregate tests, the study proceeded to test concrete made from both recycled coarse aggregate and normal aggregate using the same cement and fine aggregate. Workability test, shrinkage test, and compressive strength test were conducted. A total of 46 specimens were prepared — 40 for compressive strength testing and 6 for shrinkage testing. The paper also presents the stress-strain behavior and elastic modulus of both types of concrete samples.