Experimental and numerical investigation of the mechanical behavior of Fiber Reinforced Polyurethane Elastic Concrete Link-Slab (FRPEC-LS) under multiple loading cases

Due to the safety and durability issues associated with traditional expansion joints, link slabs have been adopted as an alternative. However, conventional concrete link slabs remain vulnerable to cracking under traffic and temperature effects. Alternative materials developed for link slabs have shown promising results, but there is still a pressing need to identify new materials with excellent mechanical properties, lower restraint demand and ease of operation. Therefore, a new Fiber Reinforced Polyurethane Elastic Concrete Link-Slab (FRPEC-LS) is proposed herein to support rapid construction and durable performance in jointless bridges. FRPEC is a novel composite material characterized by rapid hardening, high elastic deformation capacity and corrosion resistance. A two-span jointless bridge with FRPEC-LS was tested under multiple loading cases to study its load–deflection behavior, crack development, and strain response. The test results were supplemented by finite element (FE) analysis, based on which a simplified calculation model was developed and validated against the FE results. Test results indicate that the bending-tensile stress characteristic was more pronounced at the top interface between adjacent concrete deck and FRPEC. Additionally, experimental and FE analysis results showed that FRPEC-LS without a steel plate demonstrated enhanced flexibility and improved deformation accommodation. The present study contributes to the understanding of the mechanical behavior of the new FRPEC-LS under different working conditions, providing support for future research and engineering practice.