Structural behavior of continuous hybrid reinforced concrete spliced girder under monotonic and cyclic load: experimental investigation

An experimental program investigates the structural behavior of a continuous hybrid reinforced concrete girder spliced by ultra-high-performance concrete (UHPC) joint. Test parameters included the location and number of joints connecting the precast segments, type or shape of the UHPC joint (flat and key), hybridization of negative reinforcement, and type of loading (monotonic and cyclic). The joints are cast simultaneously with the deck of girders of the UHPC. The splice girders have the same length of joint of 190 mm and treat the interface by the exposed aggregate surface system to enhance the bond strength with the precast unit. The concentrated load tested the specimens at the mid-span of the girder. The experimental results are presented and discussed considering the cracking load and propagation, ultimate load and mode of failure, load to mid-span deflection relationship, stiffness, and ductility to investigate the performance of UHPC joints. In conclusion, the ultimate load was decreased due to the presence of the joint by about 17.3% for one joint specimen and 5.7% for two joints specimen, and the location of the UHPC joint over the support changed the mode of failure from flexure to shear failure caused by the high flexural capacity of the joint. The presence of the UHPC joint increased the initial stiffness of girders because of the good bond strength of the joint with the precast segment, while the ductility was decreased in the spliced girder.