Flexural Behavior and Model of Curved Bolt Connections with UHPC Grout and CFRP Tendons for Prefabricated Concrete Panels

Connections between prefabricated concrete panels (PCPs) are susceptible to cracking and damage, attracting the attention of bridge engineers. Curved bolt connections have ideal flexural performance when they have an appropriate anchorage distance. High-performance materials, such as ultrahigh-performance concrete (UHPC) and carbon fiber‒reinforced polymer (CFRP) bars, bring solutions to further reduce construction resources on-site and improve the durability and mechanical properties of curved bolt connections. In this paper, curved bolt connections with UHPC grout and CFRP tendons (UHPC–CFRP connections) for PCPs were proposed. Prediction models for the flexural capacity, cracking moment, and deflection of UHPC–CFRP connections were proposed. Full-scale flexural tests were carried out to study their working mechanism, and their flexural performances were compared with those of ordinary curved bolt connections. Three-dimensional finite-element numerical models were developed, and the influences of important design factors on flexural capacity were discussed. Both experimental and numerical results showed that the flexural behavior of the PCPs with UHPC–CFRP connections is more desirable than that of curved bolt connections with ordinary materials. The improved models are effective for predicting the flexural response of PCPs with UHPC–CFRP connections.