The strengthening of reinforced concrete structures using advanced fiber reinforced polymer (FRP) composites is a very popular practice because they are light and highly resistant to corrosion. In particular, the behavior of FRP-reinforced concrete structures is a topic that attracted lot of interest in recent years. However, the application of FRP-reinforced concrete structures requires an extensive development of reliable design equations.This study focuses on the behavior of beams reinforced with different reinforcement ratios of glass fiber reinforced polymer (GFRP) bars and concrete strength. Displacement, strains, and crack width were measured to study the behavior of beams. The results of the investigation can be summarized as follows:(1) Deflections and strains of concrete beams reinforced with GFRP re-bars are generally larger than those reinforced with steel bars; (2) the strength of the concrete has a negligible effect on crack spacing and crack width; (3) and the FRP over-reinforced concrete beams in this study are safe for design in terms of deformability.

In recent practice a half round prismatic bar has fillet welded or formed through foundry work along the centerline on rear concave surface of the horn to mitigate gap flow between fixed and movable part of the rudder system. When the gap clearance has been blocked with this practice, numerical simulations indicate that the practices are not only effective in reducing the gap flow but also in mitigating the cavitation. The blocking effects are remarkably improved when a pair of blocking bar is bisymmetrically attached with respect to centerline on the opposite convex surface of the movable part. The blocking bar could be placed on the exposed surface under maximum rudder angle. This implies that the blocking bar could be easily adopted not only in a design stage but also in a maintenance stage for mitigating rudder cavitation. In addition, the numerical simulations imply that more improvements could be anticipated through the selection of section shape of prismatic bar for gap flow blocking.

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The replacement of conventional steel reinforcement with fiber-reinforced polymer (FRP) bars was investigated previously to overcome the problem of steel reinforcement corrosion and structural deterioration in concrete structures exposed to aggressive environments. However, the lower modulus of elasticity of FRP materials and their non-yielding characteristic results in large deflection and wide cracks in FRP-reinforced concrete members. Hence, there is a need for a suitable design philosophy and for methods that can provide a reliable estimate of such behavior.This paper evaluates the behavior of simply supported concrete slabs reinforced with bars of glass fiberreinforced plastic (GFRP) and subjected to four-point monotonic loading. The slabs had sizes of 4000 × 1000 × 150 mm and 4000 × 1000 × 200 mm with different reinforcement ratios. This research investigated the flexural and shear limit states of the slabs, including pre-cracking behavior, cracking pattern and width, deflections, ultimate capacities and strains, and failure modes. The information presented is valuable for future field application and development of design guidelines for FRP-reinforced concrete structures.

The strength of reinforced concrete members may vary from the calculated or the nominal strength due to variations in the material strength and dimensions of the element. Statistical descriptions of the variabilities in loads and strengths are required in all studies pertaining to the safety of reinforced concrete members.Therefore, this paper recommends a number of values for the coefficient of variation of concrete, reinforcement, dimension and load to be used in the probability analysis. Also, this study analyzes reinforced concrete members using the Advanced First Order Second Moment (AFOSM) method using the statistical characterization of variables. This study shows that Bayes' theorem is an effective tool for updating prior probabilities when the value of a random parameter is known. Finally, the results in this paper contribute to the limit state reliabilities implied in the current design of reinforced concrete elements.