Glass fiber-reinforced polymer/steel hybrid honeycomb sandwich concept for bridge deck applications

Glass fiber-reinforced polymer (GFRP) bridge decks possess inherently high strength-to-weight ratios, but relatively low effective elastic moduli. As a result, serviceability issues govern GFRP bridge deck design. Therefore, the objective of this study was to increase the stiffness of a commercial GFRP honeycomb sandwich panel through the inclusion of steel within the cross section. GFRP-steel hybrid parametric studies were conducted to evaluate improvements on the GFRP honeycomb deck panel stiffness. Possible configurations included the embedment of steel plates within the face sheets and the placement of steel tubes within the core. Core stiffness analyses were also performed, leading to the development of the steel hexagonal honeycomb core concept. An experimental study, including large-scale beam tests, was conducted. The large-scale tests were performed to assess the equivalent flexural and shear stiffness, comparing the hybrid steel core concept and the current GFRP core design. From the large-scale beam test results, an overall stiffness increase was observed.