Design and Performance of GFRP Reinforced Bridge Decks in NOVA SCOTIA—Preliminary Analysis

Abstract

AbstractThe use of glass fibre-reinforced polymer (GFRP) reinforcement in bridge decks has gained popularity due to its corrosion resistance. With the adverse effects of frequent freeze–thaw cycles and the ingress of de-icing agents in concrete bridge decks, GFRP is proving to be an ideal solution for reinforcing material in Canada. The Canadian Highway Bridge Design Code (CSA S6-19) provides general design requirements for GFRP-reinforced bridge decks. However, there is some variability in the durability design requirements in Canada due to climatic differences across the country. There are variations in design methods (flexural design approach versus empirical design approach), as well as variations in the choice of concrete material specifications and geometric parameters such as overall deck thickness and concrete cover. In addition, limited research has been completed to assess the long-term durability performance of GFRP bars in concrete decks and any impact on remaining capacity and reliability. The primary objectives of this research programme are to 1) provide a review of the design methods for GFRP-reinforced bridge decks in Nova Scotia and 2) recommend regional specific durability-based design criteria for GFRP-reinforced bridge decks. This paper presents parts of the two phases of the research programme. Phase I consists of evaluating the design of existing GFRP-reinforced bridge decks in Nova Scotia and performing statistical analysis. Phase II consists of developing a framework to assess the structural reliability of bridge deck design options subjected to the province’s specific environmental exposure. Analyses performed in Phase I show that all considered bridge decks meet the flexural strength requirements of CSA S6-19 and that the parts of the deck subjected to transverse negative moments are the most critical zone for the serviceability crack width criteria in the flexural design method. In Phase II, the analysis of Weight-In-Motion (WIM) data from a highway in Nova Scotia shows that the third axle of Class 13 (7 or more axles) vehicles has the highest mean loads of all vehicle classes. The proposed design criteria provided at the end of this research programme will serve as a design aid for bridge engineers in Atlantic Canada to evaluate existing GFRP-reinforced bridge decks and optimize the design of new ones.KeywordsGFRPBridgeBridge DeckConcreteDurabilityNova Scotia