This research focuses on developing and measuring the mechanical behavior of ultrahigh-performance fiber-reinforced concrete (UHPFRC), transverse, field-cast connections between precast bridge deck elements. The connections had a closed shape, exposed aggregates, and lap splice length of 10 bar diameters (d_b). Three slab designs were considered: high-performance concrete (HPC), high- performance fiber-reinforced concrete (HPFRC), and hybrid HPFRC and UHPFRC. The first set of specimens was subjected to quasi-static loads up to failure, while the second set was subjected to cyclic fatigue loads prior to quasi-static loading to failure. Experimental results showed that all precast bridge decks with UHPFRC connections presented the same stiffness and ultimate strength as equivalent cast-in-place (CIP) slabs. Finite-elements models reproduced experimental results accurately and were used for predicting the mechanical behavior of continuous bridge slabs. Parametric studies demonstrated that, under various loading conditions, transverse UHPFRC field-cast connections do not modify the stiffness, ultimate strength, and failure mode of a slab differently than the equivalent CIP systems.

Development in ultra-high-performance fiber-reinforced concrete (UHPFRC) structural applications that has taken place over the last two decades has generated innovative concepts that could significantly impact the concrete construction practice. The transition from conventional concrete with brittle behavior to strain-hardening behavior in direct tension allows consideration of the design of innovative structural components and offers development of new techniques for rehabilitation. Building on experimental results of internally instrumented reinforcing bars, this paper investigates the impact of tensile characteristics of UHPFRC on the performance of lap splice connections using a refined three-dimensional (3D) finite-element (FE) model at rib scale and a 3D concrete constitutive model implemented in a computer program. The results show that the model reproduces with accuracy the experimental behavior of lap splice connections in UHPFRC in terms of maximum strength, splitting failure mode, crack...