Parameter inversion analysis of rubber-mortar cohesive zone model in rubberized concrete

The rapid development of urban rail transit has brought convenience to travel, but also causes serious environmental vibration problems. Some scholars have proposed rubberized concrete invert-filling as a damping measure. The addition of rubber particles creates the rubber-mortar interface, which is an important factor that affects the damping performance of rubberized concrete. In this study, we propose an interface modification method of coating rubber with zinc stearate powder to improve the damping performance of rubberized concrete. The stiffness, strength, and fracture energy of the rubber-mortar interface were obtained by an inversion analysis technique based on numerical simulation and experimental results. The results show that: (1) The uniaxial tensile test determined the bonding strength of the rubber-mortar interface treated with water, sodium hydroxide, and zinc stearate as 0.144 MPa, 0.160 MPa, and 0.074 MPa, respectively. (2) Based on numerical simulations and experimental results, the bonding strength of the rubber-mortar interface treated by three methods was 0.142 MPa, 0.146 MPa, and 0.080 MPa, respectively, with relative errors of less than 10 %. (3) Compared with the interface obtained by water treatment, the interface modified by zinc stearate showed a 43.7 % reduction in bonding strength and a 46.0 % reduction in fracture energy.