A Review of Shear and Bending Performance Tests of Wet Joint Connections between New and Old Bridges
Chenyang Fan *
School of Civil Engineering and Transportation, North China University of Water Resources and Electric Power, Zhengzhou 450045, China.
*Author to whom correspondence should be addressed.
Abstract
The wet joint, as the core connection part for the splicing of new and old bridges and the assembly of prefabricated components, its shear and bending resistance directly determines the integrity, safety and durability of the bridge structure. This paper focuses on the shear and bending performance tests of the wet joint between new and old bridges, systematically reviewing the test methods, key influencing factors, mechanical calculation models and engineering application progress of related research. The study shows that the Z-type shear test is the mainstream method for evaluating the shear performance of the interface of the wet joint, and the height of the shear surface of the specimen, the loading rate and the testing technology significantly affect the reliability of the results; the bending performance of the wet joint plate is mainly characterized by cracking load, ultimate bearing capacity, crack width and stiffness attenuation; the interface treatment method, joint construction form, material properties, lateral prestress and size effect are the core factors affecting the two performances; calculation methods based on shear friction theory, tension-compression bar model and modified formula of the code have been preliminarily applied in engineering, but the adaptability to the fiber reinforcement effect of UHPC and the effect of dynamic loads still need to be improved. This paper can provide technical references for the design, test optimization and performance improvement of the wet joint in the splicing project of new and old bridges.
Keywords: Old-new concrete bridge, wet joints, Z-type shear resistance test, flexural performance, ultra-high performance concrete (UHPC), mechanical model