A Study on Bond Properties between NSC Substrate and UHPC

Ultra-high performance concrete (UHPC) is suitable for the durable rehabilitation and strengthening of deteriorated normal strength concrete (NSC) structures due to its excellent characteristics, such as superior compressive strength, high tensile capacity, and excellent bond properties. However, a successful repair depends on whether the UHPC-NSC interface can provide good bonding performance under various applied loads and working conditions throughout its bond properties. In this article, review on the mix proportion and bond characteristic of UHPC-NSC was addressed. This will be the advantages for the ongoing research with the development of UHPC materials choose from various local materials. The bond characteristics between the NSC substrate and UHPC by testing methods such as splitting tensile, and direct tensile tests were summarized. In additional, it was indicated that the UHPC overlay achieved superior interfacial bond performance for the rehabilitation of concrete structures, with the appropriate surface substrate roughness.