Basic Property and Compressive Damage Constitutive Model of Full Recycled Aggregate Concrete

Abstract:

To realize the maximum and low-carbon utilization of waste concrete resources， a novel full recycled aggregate concrete （FRAC） was proposed， i.e.， using the recycled coarse and fine aggregates processed from waste concrete to replace natural sand and gravel to prepare new concrete. Taking four different aggregate combinations as parameter variables， the mechanical properties， shrinkage characteristics， and uniaxial compressive stress-strain relationship of FRAC were experimentally studied. The results show that the recycled aggregate combinations have an adverse effect on the development of concrete compressive strength， especially for concrete with full recycled fine aggregate. But by adjusting the mixing proportion， the FRAC can meet the design requirement for strength grade above C30. The full recycled aggregate combination increases the drying shrinkage of concrete， especially at the early stages. When FRAC has a small deformation under uniaxial compression， the damage began to develop and accumulate obviously. By considering the initial damage and mechanical damage， a damage constitutive model for FRAC under compression was established， which could well describe its stress-strain behaviour. Finally， the future research direction of improving the mechanical properties of FRAC was prospected.

Key words:full recycled aggregate concrete(FRAC);recycled coarse aggregate;recycled fine aggregate;mechanical property;shrinkage;damage constitutive relationship