Characteristics of Recycled Concrete Aggregate and its Implementation for Pavement Base Applications: A Review

Significant amounts of Natural Aggregate (NA) materials are being used to meet the requirements of pavement structure. Simultaneously, enormous amounts of demolition waste, such as demolished concrete and reclaimed pavement materials, are dumped into landfills along roadsides, creating pressure on the environment. Therefore, the recycling of demolished materials and their utilization for pavement construction would result in conservation of natural aggregates, this would alleviate the problems related to geo-environment and bring several benefits for the environment and ensure sustainability. Several studies have been carried out to describe the mechanical properties of recycled concrete aggregate (RCA) with and without stabilization. A thorough understanding of performance-related engineering properties of unbound RCA and stabilized RCA is essential for mechanistic-empirical pavement design. This paper reviewed the mechanical properties such as compaction, California bearing ratio, resilient modulus, and permanent deformation in the case of unbound RCA, and unconfined compressive strength, flexural strength, and stiffness for stabilized RCA from accessible works of literature on the application of RCA for pavement base. The findings from the literature indicated that RCA is source-dependent, moisture sensitive, and subjected to particle breakdown under wheel load that results in reduced shear strength. Further, if RCA is treated with mechanical stabilization by geosynthetics, the interface shear strength properties improve, and permanent deformation is reduced. Chemically stabilized RCA is a promising technique as its strength and durability complied with stabilized NA. Therefore, this review will be helpful for pavement engineering practitioners to explore RCA use in pavement base or subbase layers.

Keywords:

Recycled concrete aggregate , Stabilization , Mechanical properties , Environmental safety