Performance of fiber-reinforced concrete link slabs with embedded steel and GFRP rebars

• A holistic investigation was carried out on link slabs for jointless bridge applications. • Link slabs made with fiber-reinforced concrete and two rebar alternatives were examined. • Various performance measures were extracted from full-scale experimental tests. • Effect of reinforcement details was investigated through a set of numerical simulations. • Materials and structural configurations appropriate for link slabs were recommended. Expansion joints in bridge superstructures are often difficult to maintain, leading to the problems associated with water leakage and debris accumulation. As a potential solution, link slabs can be placed at the expansion joints, providing a continuous deck system. Despite the promise of such a system, there have been standing questions on the materials of choice and structural configurations appropriate for link slabs, especially in their transition zone from the bridge deck to their debonded region. This motivated the current study to investigate various reinforcement alternatives using full-scale laboratory tests and numerical simulations. To achieve a satisfactory crack resistance, a fiber-reinforced concrete (FRC) mixture was developed for the tested link slabs. In addition, two rebar alternatives, i.e., steel and GFRP rebars, were evaluated to ensure a proper transfer of stresses induced by negative bending moments (due to continuity) and to limit the width of cracks on the top surface of the link slabs, where they are directly exposed to water and deleterious agents. The full-scale performance was examined under increasing vertical loads applied to the midpoint of two individual spans connected by a link slab. This included an investigation of various structural response measures, such as strains in the FRC and embedded rebars. The study was then extended by performing a set of finite-element simulations to understand the effects of reinforcement details. The outcome of this study provided holistic information on how flexible link slabs can be utilized for jointless bridge superstructures, addressing the concerns regarding their performance and durability.