Structural Performance of Bridge Barrier With Normal and Fiber-Reinforced Concrete

Concrete barriers are categorized into various test levels for different vehicle crash criteria and traffic conditions based on design codes. They are designed per the crash and safety requirements specified for each barrier test level, as defined in the Canadian Highway Bridge Design Code (CHBDC). A steel-reinforced concrete barrier can be designed using the yield-line theory based on available yield-line capacity equations in the literature. However, further analysis is required to provide design recommendations for bridge designers and code writers to use these equations. Fiber-Reinforced Concrete (FRC) barriers are proposed for efficient design in terms of cost and performance. Three configurations of TL-5 FRC barrier were developed considering only stainless-steel bars at the front face of the barrier, with no back side reinforcement. This study conducts numerical and experimental studies on the analysis and design of bridge barriers made of normal concrete and FRC. The research program includes (i) numerical study of five different bridge barrier types based on CHBDC definitions and using the available yield-line failure capacity equations obtained from previous studies, (ii) experimental study on flexural performance of FRC beam specimens for fiber percentage determination and (iii) full-scale testing of three developed TL-5 bridge barrier made of FRC. Yield-line analysis showed that recently developed trapezoidal yield-line capacity equations provide the most critical load capacity for all bridge barrier types. Recommendations for the use of such methodology in the design of steel-reinforced barriers were drawn. The experimental investigation on FRC beams revealed that 1% synthetic fiber volume is the best to produce FRC mix for barrier construction per CHBDC requirements and to provide proper concrete surface appearance. The experimental tests on full-scale barriers showed that three developed FRC, stainless-steel reinforced barriers exhibited much greater transverse load-carrying capacities at the interior and end locations than the CHBDC factored design load. Based on the barrier’s structural details, three failure modes were observed, namely: punching shear failure at the top surface of the barrier wall, concrete breakout of the embedded bent stainless-steel bars in the concrete base and trapezoidal yield-line failure with flexural-shear cracks.