Impact Test of GFRP Reinforced Concrete Bridge Barriers

The aim of this proposal is to provide test and evaluation of glass fiber reinforced polymer (GFRP) bars for concrete bridge barriers. The “steel-free” concrete bridge structure concepts have gained wider acceptance in current practice due to reduced material cost and validated field performance from the past research. However, on-site bending is still not possible for GFRP bars, which causes increase in the number of GFRP bars used in construction. Alternatively, headed end GFRP bars may address this problem. Existing research has conducted that both experimental and numerical modeling investigations to achieve an optimum design for GFRP reinforcement in concrete structures, especially railings. It was suggested that the headed-end GFRP bars can provide sufficient resistance, however, with an added cost. Therefore, anchorage GFRP bars with modified bending radius has also been suggested to achieve same resistance with lower cost. Considering the on-going effort in seeking the optimized GFRP configurations for concrete bridge railings, the preliminary design and validation is critical in finding the best design prior to the field implementation of GFRP bars for concrete bridge railings in the state of Missouri.

The research team from Missouri S&T along with industrial partners and MoDOT engineers has an on-going research project on the preliminary design and numerical evaluation of the GFRP reinforced concrete barriers. From the preliminary findings, the two-piece GFRP designs were selected and moved into numerical investigation stage. The preliminary numerical results indicate the existing design can withstand the MASH specifications. However, the dynamic impact test is needed for validation. Considering the high cost in full-scale vehicle impact test, the team is considering alternative testing method which has significantly higher cost-effectiveness. The pendulum impact test is proposed for this MATC proposal.

The prototype design of the GFRP reinforcement for concrete bridge barriers will be validated or improved using the pendulum crush test.

Download the Final Report