The Effect of the Recycled Aggregate Class M Size on Strength Properties of Concrete

Abstract

The study of recycled concrete preparation technology under economic and technical feasibility is getting more serious attention in each country due to the impact and contribution to environmental protection which will lead to the sustainable development of human society. This research was conducted by controlling variables test. Three type of aggregates are natural coarse aggregate (N), recycled coarse aggregate prepared in the laboratory using a small crusher (RL) and recycled aggregate prepared by the factory using a large crusher imported from Japan (RP).  To assess the influence of aggregates size of recycled coarse aggregates Class M of JIS on the strength characteristics of concrete with different diameters, Concrete prepared according to ASTM C192 with recycled aggregates of 4.75 - 13.2 mm (A), 13.2-19 mm (B) and 19- 31.5 mm (C) were subjected to a series of unconfined pressure tests after curing for 28 days according to ASTM C39. The study found a relationship between the mechanical characteristics of recycled aggregate concrete and the aggregates particle size. A regression model of recycled concrete was proposed to predict the modulus of elasticity and to adjust the design of mix proportions. These results would contribute to adjust the remediation mixture for recycling concrete plants by considering the influence of recycled aggregate size.