EXPERIMENTAL AND MECHANICAL ANALYSIS OF BOND-SLIP PERFORMANCE BETWEEN RECYCLED CONCRETE AND REBAR

Good bond performance is a prerequisite to ensure that the recycled concrete and the rebar can work together. According to the pull-out test with 120 test specimens, the bond-slip performance between the recycled concrete and the rebar is investigated using the theory of non-equilibrium thermodynamics and damage mechanics. The bond-slip constitutive model is proposed and the analysis result shows that the model has better simulation effect. The characteristics of the energy conservation and dissipation during the bond failure process are analyzed, and then the formula to represent the dissipated energy and elastic deformation energy are proposed. The relationship between the initial elastic deformation energy and the limit elastic deformation energy is studied. The main factors affecting the bond performance are analyzed based on the constitutive energy. Then, this paper proposes the concept of relative damage variation which defines the interface relative damage variation, and proposes the equation of relative damage to slip. Besides, the initial damage, the stages of interface damage development and the growth rate of interface damage are analyzed. The results of the present study could provide fundamental research data to promote the application of reinforced recycled concrete structure.