The use of recycled concrete aggregate in structural concrete around South East Queensland

Abstract

This study aims to develop the best economic solution by use of recycled aggregate in structural concrete to reduce the environmental impact around South East Queensland. Therefore, the objective of this project is to investigate the hardness properties of Recycled Concrete Aggregate including slump, density, compressive strength, tensile strength, modulus of elasticity and drying shrinkage. This is also to determine the durability and permeability, quality and cleanliness that are suitable for application in high strength concrete up to 60MPa compared with 100% natural aggregate from the pits around South East Queensland which is provided from local companies. To determining the above properties of the recycled aggregate by studying the influence of 100 percent recycled aggregate in concrete. The Laboratory trials were conducted to investigate the possibility of using 100 percent of recycled aggregate (20mm, 14mm and 10mm) with 25 percent of fly ash (low volume of 20% fly ash is minimum requirement by MainRoads specifications) to replace part of the cement in concrete, compared with natural aggregate. The project has also researched the costs for what is the most economical solution to making recycled aggregate for high quality concrete around South East Queensland by consulting with the local technical specialists and related firms to broadening the RCA use for structural concrete in the concrete industry in Australia.