Abstract: In line with the principle of Sidoroff energy equivalence,the key parameters of CDP model such as plastic damage factor,inelastic strain,and cracking strain were studied. A meso-structure model of recycled concrete was designed based on random polygonal aggregate,old mortar,new mortar,aggregate-old mortar interface,old-new mortar interface and aggregate-new mortar interface. Some crucial compression and tension properties of recycled concrete were studied,including damage development process,stress level in all directions,failure forms,and damage values. The calculation results were compared and analyzed with test results. Research shows that the damage factors based on the principle of energy equivalence is suitable for ABAQUS modeling,and this modeling method is concise and of good convergence. The cloud diagram of compression damage of recycled concrete displays V-shape,while tension damage I-shape,and the tensile and compression damage values both reached 0.956. The simulation calculation results are in good agreement with the test results,indicating that the mesoscopic model of recycled concrete based on random polygonal aggregates is rational.

Key words: recycled concrete, plastic damage, six-phase material, polygonal random aggregate, mesoscopic properties