Mechanical behavior and constitutive relationship of the three types of recycled coarse aggregate concrete based on standard classification

Abstract

To investigate the effect of classification of recycled coarse aggregate on the mechanical behaviors of recycled aggregate concrete (RAC), a total of 150 RAC testing blocks were designed based on the Chinese standard GB/T 25177-2010, taking recycled coarse aggregate and substitution ratio as factors in a series of tests, including cubic compression, prismatic compression, quadrate plate compression and elastic modulus. During the whole testing period, from initial compression to destruction, important characteristic parameters such as stress–strain curve, elastic modulus, peak stress, and peak strain were obtained. The effect of classification of recycled coarse aggregate on the destruction mechanism and mechanical performances of RAC is investigated and analyzed based on the test phenomenon, microscopic structure evolution, damage process,displacement ductility, energy dissipation ability, constitutive relationship, etc. It is understood from the test results that cubic compressive strength, prismatic compressive strength, elastic modulus and damage development speed all follow a tendency of Class I > Class II > Class III, while deformation ductility coefficient has a tendency of Class II > Class I > Class III. Moreover, damage constitutive relationship of RAC is brought forward showing that the theoretical approach can fully reflect the experimental results.