Investigation of Shear-critical One-way Concrete Slabs Internally Reinforced with GFRP Bars

With increasing attractiveness among industry professionals, the application of Glass Fiber Reinforced Polymer (GFRP) bars as internal reinforcement for concrete structures has been rapidly growing for specific conditions such as corrosive or electromagnetic environment. Only limited design guidelines are available primarily due to the fact that the experimental database is also limited. This dissertation presents both experimental data and numerical analysis of GFRP reinforced slabs subjected to one-way shear. The experimental component was conducted on 20 specimens categorized into two groups of small and large slabs with cross-sectional dimensions of 200x1000 mm and 400x1500 mm, and shear-span-to-depth ratios of 6.6 and 3, respectively. The specimens were simply supported, and tested to failure under monotonic four-point loading. To explore the shear behavior, variables included concrete strength, longitudinal reinforcement ratio, longitudinal bar spacing, bar type and surface characteristics, and amount of shear resisting GFRP headed studs. The effect of each variable was investigated and the main findings were reported. In general, it was found that using high strength concrete may not always be of advantageous, and in small slabs particularly resulted lower capacity. Improved performance was observed by increasing the reinforcement ratio, and reducing longitudinal bar spacing. Application of GFRP headed studs, acting as shear reinforcement, also showed promising results in specimens with larger depth and made with normal strength concrete. The results from the current experimental work and those from the previously tested specimens were compared against the predictions using selected design codes including ACI440.1R-15, CAN/CSA S6-14, CAN/CSA S806-12, and previously suggested modifications incorporating 2nd orders of and θ. A new optimized equation was proposed for mid-depth longitudinal strain, and improvement was observed in the prediction of shear capacities compared with studied design codes and previously suggested methods.Ph.D