Study of feasibility and mechanical properties for producing high-flowing concrete with recycled coarse aggregates

Abstract

This study uses crushed waste concrete with compressive strength ranged from 210 to 350 kgf/cm(2), as recycled aggregates to produce high-flowing concrete. Proper amount of fly ash (25%, 30%) and superplasticizer is added. The water-to-cementitious material ratio (w/cm) was 0.50, 0.55, and 0.60. The engineering properties including compressive strength, splitting tensile strength and bond strength were tested. Meanwhile, the results were compared with those from specimens made of natural-aggregate with same mix proportions. The physical properties of recycled aggregates obtained from crushed waste concrete of this experiment meet CNS1240 (equivalent to ASTM C33) specifications and requirements. The engineering properties of concretes made from natural and recycled aggregates showed only slight differences. The utilization of recycled aggregates for high flowing concrete is confirmed and is an environment friendly material.