Characterization study on recycled coarse aggregate for its utilization in concrete - A review

Abstract

Industrialization and urbanization are two major factors that contribute to the scarcity in construction materials furthermore leading to dependency on alternative materials in construction. Consequently, rehabilitation and retrofitting of structures leads to the generation of Construction and Demolition(C&D) waste which is to be effectively reutilized/disposed. Such C&D wastes can be reutilized as coarse aggregates in concrete termed as recycled aggregate concrete to achieve sustainability in construction. Presence of adhered mortar on the surface of recycled aggregates tends to reduce the quality of recycled aggregate concrete. This paper reviews the statistical data on the generation of C&D wastes around the globe and its percentage of reutilization with a comparison on physical characteristics of C&D wastes with natural coarse aggregate in concrete. Comparative studies on the physical characteristics of recycled aggregates performed by various researchers embark with conclusive remarks to specify its limitation on utilization in structural applications due to the presence of adhered mortar on its surface.

Microbial Technique to Treat Recycled Aggregates from Construction Waste for its Effective reutilization in Concrete

“…The strength of R-10-N and R-30-N was 3.9% more than R-0-N at 28 days. The trivial strength enhancement was due to the angularity of RCA ensuing from the recycling process (Jagan et al 2020;Sivamani et al 2021a). The strength of R-50-N was reduced by 11.42% and the strength of R-100-N was reduced by 20.06% at 28 days.…”

Sustainable Approach of Utilization of Limestone and Treated Construction Wastes as Aggregates in the Production of High Temperature Resistant Green Concrete

“…However, the CS of RC-50 and RC-100 was lowered by 10.63% and 21.65% at 7 days and 6.44% and 16.67% at 28 days. The reduction in the CS of RAC was attributed to the attached mortar on RA with micro-voids that absorb more water than NA (Jagan et al 2020, Kothari et al 2016. So, carbonation treatment was done to RA and so enhancement in the CS of RAC was observed.…”

Performance studies on energy efficient paver block with treated recycled aggregate

“…The water absorption of BRC-100-RF-0 was only 2.86% more compared to RC-0-RF-0 and the water absorption of RC-0-CRF-100 was only 1.24% more compared to RC-0-RF-0. The bio-deposition of RCA precipitates CaCO3 that bonds on the surface of RCA [13,21] whereas carbonation treatment to RFA produces CaCO3 that impregnates into the micro-cracks of the RFA resulting in the reduced water absorption compared to the paver block with untreated RCA and RFA [2,4,12].…”

“…Extensive researches were carried out with the utilization of recycled construction wastes as fine aggregate (RFA) and coarse aggregate (RCA) in the concrete. Higher utilization of RFA and RCA in the concrete affects the concrete properties due to its inferior quality ensuing from higher porosity [4][5][6][7]. So, the researches focus on suitable treatments to RCA and RFA to enhance its quality by reducing its water absorption.…”