Steel-Free Hybrid FRP Stiffened Panel-Concrete Deck System

Synopsis: This paper presents a design, analysis, and characterization of a hybrid deck system incorporating a thin Fiber Reinforced Polymer (FRP) stiffened hat-panel configured stay-in-place formwork that serves as flexural reinforcement with steel-free concrete poured on top. Quasi-static tests were conducted to first investigate the flexural behavior of the system. To understand the deck performance under traffic loads that induce repetitive stress cycles during the service life, a two-span continuous deck specimen (1.22 m wide) was tested by subjecting it to a total of 2.36 million cycles of load that simulates an AASHTO design truck with inclusion of the impact factor at both low and high magnitudes. The concrete-panel interfacial response due to the presence of sand and interlocking ribs was characterized by performing a series of 610 mm wide deck section tests, the results of which were used to calibrate a finiteelement (FE) based analytical model. The effect of the shear span-to-depth ratio, carbon fiber reinforcement ratio, and rib spacing were then evaluated by performing a parametric study using the calibrated nonlinear FE model. A simplified design approach is also proposed.