Recycled Construction and Demolition Waste as Aggregates: A Study

Rapid urbanization and increased infrastructural growth had led to a rise in the requirement of natural aggregates and other resources. On the other hand, a rise in the generation of Construction and Demolition Waste (CDW) is also reported from all parts of the world which is putting immense pressure on our landfill system when these waste materials are not properly recycled or reused. Reuse of the recycled CDW in various minor applications are tried and found to be successful in different scenarios. This study aims to provide an insight into the use of Recycled Concrete Aggregates (RCA) as a substitute for the Natural Aggregates (NA). RCA is engendered from the construction and demolition waste (CDW). The use of RCA in concrete has revealed to be a sustainable and economical alternative to natural aggregate where the properties of recycled aggregate concrete must be equal to that of NA concrete. This chapter focusses on experimental studies to understand the particle size distribution, water absorption, soundness of course aggregates, mechanical properties such as strength against impact, compressive and abrasive forces with respect to natural aggregates. The RCA has performed less compared to NA. It is found that studies are done to understand the strength degradation, and hardened properties of concrete when NA is replaced with RCA. The RCA has performed well as compared to concrete made of NA in the strength. This concludes that revising the w/c will help to meet the standards. It is observed that the quality of concrete made of RCA will have slight reduction as per regular standard design; this can be improved by the addition of saw dust. The concrete cubes have been designed with series of replacements of saw dust like 30%, 50% of RFA. It observed that 30% replacements of RFA with saw dust have met the standards. Thus, RCA can be effectively used for structural applications, thereby reducing the load on natural resources leading to a sustainable construction practice.