Review on the Importance of Coarse Recycled Concrete Aggregates as Alternative Construction Materials

Abstract

Recycled concrete aggregates are one of the most important supplementary building materials used in the production of "green concrete" or recycled aggregate concrete. They are collected from construction and demolition trash, which decreases construction industry waste (RAC). By size, aggregates are divided into coarse and fine aggregate. Focus of research is on the replacement of coarse aggregate in concrete using coarse recycled concrete aggregate (CRCA). It is vital to provide a major overview on the main developments and advancements in the characterization of CRCA and in the comprehension of the behaviour of concrete containing this, taking into account its varied attributes such as freshness, hardness, and durability. Because of the weak attached mortar present on its surface, CRCA's performance in all areas falls as the replacement percentage rises. Different treatments such as washing and drying of aggregate, changed mixing sequences, carbonation, slurry and microbiological treatments, CO2 mineralization and air jigging process can mitigate the negative effects of CRCA in the concrete. This study discusses the issues raised by the widespread use of CRCA on concrete and the effectiveness of the numerous treatment solutions that are now available in the industry.