Systematic comparison of different recycled fine aggregates from construction and demolition wastes in OPC concrete and PPC concrete

Abstract

River sand is widely used as fine aggregates in concrete. Several countries have prohibited the use of river sand in construction owing to the devastating effects of excessive river sand mining. Hence, the need for alternative fine aggregates is substantially enhanced in the construction sector. The disposal of construction and demolition wastes into landfills is a major concern due to the stringent environmental regulations. Using recycled fine aggregates from construction and demolition wastes as alternative fine aggregates is an environmentally viable solution for excessive river sand mining. Although numerous previous studies on recycled fine aggregates are available, a comprehensive review of the comparative assessment of different recycled aggregates derived from construction and demolition wastes is highly limited. Therefore, the potential reuse of various types of recycled fine aggregates from construction and demolition wastes such as concrete, brick, ceramic and marble wastes as fine aggregates in ordinary concrete and PPC concrete is presented in the review. The influence of recycled fine aggregates on fresh properties such as workability, air content and density is presented. Besides, compressive strength, tensile strength, flexural strength, water absorption, carbonation and shrinkage of recycled fine aggregates used in ordinary concrete and PPC concrete are methodically compared. High water absorption of the recycled fine aggregates lowers the workability of concrete. Reduction in the density of concrete is observed due to the increased porosity while replacing river sand with recycled fine aggregates. Increase in the carbonation depth, air content and shrinkage are witnessed for all types of recycled fine aggregates incorporated concretes.