Fracture performance and fracture characteristics of concrete members with cold joints: Numerical simulation

•Deterioration of concrete fracture performance by pouring interval.•Mesoscopic model of three-point bending of concrete member with cold joints.•Calculation element for simulating cold joints.•The relationship between cold joint parameters and pouring interval time. This paper investigates the effect of pouring interval on the fracture performance and fracture characteristics of concrete beam with cold joints through three-point bending experiments and a mesoscopic model. The results show that when the pouring interval exceeded the initial and final setting times of concrete, the ultimate load-bearing capacity of the structure decreased by 21% and 53%, respectively. The use of cohesive elements to simulate cold joints was reliable. The degradation of the stiffness weakening section before the peak of the load–displacement of the loading point (P-δ) curve was attributed to the location of microcracks. When the pouring interval exceeded the initial and final setting times, the attenuation amplitude of the fracture energy of the cold joint were 37% and 75%, respectively. The attenuation amplitude of the damage initial stress were 6% and 45%, respectively.