Self-sensing performance and theoretical model for the interface of self-sensing engineered cementitious composites and conductive concrete under shear loading

This research aims to explore the shear behavior, self-sensing capabilities, and self-sensing model of interface between self-sensing engineered cementitious composites (ECC) and conductive concrete under shear loading. Key variables examined included the packing type of self-sensing ECC, interface roughness, and electrode placement ( L -type and O-type measurements) using the two-electrode method. The findings revealed that the packing types of self-sensing ECC were instrumental in both the shear and self-sensing properties of interface. Moreover, optimizing the filler types could notably enhance the shear and self-sensing capabilities of interface. The interfacial shear strength and interfacial resistance change rate of CS-B-L specimens are 26.43 % and 258.03 % higher than those of CG-B-L specimens, respectively. Interface roughness positively impacted its shear properties, but adversely affected self-sensing capabilities. When the interface roughness level increases from A to C, the interfacial shear strength of the CS-L specimen increases by 21.07 %. However, the change rate of the interface resistance value decreases by 63.05 %. While greater roughness improved interfacial shear strength, it concurrently reduced self-sensing performance. Furthermore, the placement of electrodes significantly influenced interface’s self-sensing performance. The L -type measurement method was more sensitive to the damage degree of interface, while the O-type measurement method was relatively weak in sensing damage degree of interface due to its different layout paths. An interface self-sensing model was developed based on the shear damage mechanism of interface between self-sensing ECC and concrete. The outcomes of this study pave the way for implementing self-sensing ECC and concrete interfaces in real-world structures (e.g., joints or repairs) for real-time damage assessment and early warning systems, thereby enhancing structural safety and reducing maintenance costs. • The feasibility of the self-sensing capabilities of the interface between self-sensing ECC and conductive concrete was studied experimentally for the first time. • This paper innovatively investigated the influence of electrode layout position on the self-sensing performance at the interface between self-sensing ECC and conductive concrete, systematically revealing the self-sensing characteristics under various electrode layout schemes. • A self-sensing theoretical model of self-sensing ECC and conductive concrete was innovatively established, which could effectively predict the relationship between interface slip and resistance change rate.