Testing and Evaluation of Polyurethane-Based GFRP Sandwich Bridge Deck Panels with Polyurethane Foam Core

Abstract

This paper presents the evaluation of an innovative low-cost small-scale prototype deck panel under monotonic and fatigue bending. This new system introduces a trapezoidal-shaped polyurethane foam core with a thermoset polyurethane resin that has a longer pot life to facilitate the infusion process. The proposed panel exhibited a higher structural performance in terms of flexural stiffness, strength, and shear stiffness. The panels consist of two glass fiber–reinforced polymer (GFRP) facings with webs of bidirectional E-glass–woven fabric that are separated by a trapezoidal-shaped low-density polyurethane foam. The GFRP panels were manufactured using a one-step vacuum-assisted resin transfer molding process. The specimens studied were constructed in the Composite Manufacturing Laboratory in the Mechanical and Aerospace Engineering Department at Missouri University of Science and Technology. Small-scale prototype deck panels were tested both statically and dynamically in four-point bending to investigate their flexural behavior. The ultimate bearing capacity of the proposed sandwich panels was determined from compression crushing tests. In addition, the load-deflection behavior of the proposed panel was investigated under three loading conditions: compression, static flexure, and dynamic flexure. The initial failure mode for all panels was localized outward-compression skin wrinkling of the top facing. The ultimate failure was caused by local crushing of the top facing under the loading point due to excessive compressive stresses. First-order shear deformation theory was used to predict the panel deformation in the service limit state. In general, the analytical results were found to be in good agreement with the experimental findings.