Finite element analysis of flexural behavior of precast segmental UHPC beams with prestressed bolted hybrid joints

Abstract

To further enhance the joint mechanical performance in precast segmental ultra-high performance concrete (UHPC) beams, a new hybrid joint configuration combining prestressed strands and bolt connection (with or without epoxy resin at the joint surface) was proposed. The concept of the bolt connection stems from the design of steel structures. This new hybrid joint takes advantages of the high ductility of UHPC. This study developed a three dimensional finite element (FE) model to investigate the flexural behavior of precast segmental UHPC beams with the new prestressed bolted hybrid joints. All the structural components except for steel reinforcement bars were simulated through eight-node linear brick elements with incompatible modes. The interaction of the structural components and non-linear material properties were taken into account in the model. The prestressing force was applied on the beam by the equivalent temperature drop method and pre-tightening forces of high strength bolts were applied by the function of Bolt Load available in ABAQUS software. The FE results were compared with the previous experimental results in terms of load-deflection behaviors, characteristic loads, and failure modes for verification of the accuracy of the developed FE model. Based on the validated FE models, parametric studies were conducted to investigate effects of the friction coefficient of the steel plate, the amounts of prestressed steel strands, and the high strength bolt borehole diameter on the flexural behavior of precast segmental UHPC beams. This study might provide a reference for future use and design of precast segmental UHPC beams with prestressed bolted hybrid joints.