Research on the influence of ultraviolet aging on the interfacial cracking characteristics of warm mix crumb rubber modified asphalt mortar

•The digital image correlation technology is applied to the single-edge notch bending test.•UV aging accelerates the Interfacial crack growth rate of Asphalt mortar.•UV aging can accelerate the interfacial damage of asphalt mortar and reduce the interfacial bond strength.•Warm mixing agent can increase the interfacial crack propagation and damage resistance of crumb rubber asphalt mortar.•The influence factors of interface crack propagation path are discussed. In order to study the effect of ultraviolet (UV) aging on the interfacial cracking of SDYK surfactant warm mix crumb rubber modified asphalt mortar (CRS-WAM), EM viscosity reducer warm mix crumb rubber modified asphalt mortar (CRE-WAM) and hot mix crumb rubber modified asphalt mortar (CR-HAM), the digital image correlation (DIC) technology was applied to the single-edge notch bending (SENB) test of warm mix crumb rubber modified asphalt mortar(CR-WAM). Firstly, the effect of UV aging on the interface crack growth rate between CR-WAM and CR-HAM is analyzed. Secondly, based on DIC horizontal strain field (Exx) and statistical principle, a new interface damage factor DI is proposed. Finally, the influence factors of interface crack propagation path of asphalt mortar are analyzed by finite element method. The results show that the interfacial crack growth rate of asphalt mortar becomes faster after UV aging, and the crack propagation rate becomes faster and faster with the increase of UV aging time. DI can reflect the interfacial damage of asphalt mortar in real time, with the increase of UV aging time, the cumulative speed of DI value becomes faster and faster, and the interfacial bond strength becomes lower and lower. The crack growth rate and DI value of two kinds of CR-WAM are always lower than that of CR-HAM, CRS-WAM has the best interfacial bond strength and crack growth resistance, followed by CRE-WAM. The SENB test finite element model has a higher degree of agreement with the DIC results, the greater the interfacial adhesion, the smaller the fracture energy, the shorter the interface and the greater the interface inclination angle, the asphalt mortar is less likely to crack.