Prediction of Flexural and Shear Strength of Concrete Squat Walls Reinforced with GFRP Bars

This paper presents an original study aimed at predicting the ultimate flexural and shear strengths of glass fiber–reinforced polymer (GFRP) RC squat walls subjected to quasi-static reversed cyclic lateral loading. Predicting the strength of GFRP-reinforced squat walls is critical for their safe design and acceptance of GFRP bar as reinforcement in such lateral-resisting structural elements. The test results of squat walls reinforced solely with GFRP bars have demonstrated their feasibility in resisting lateral loads and pointed to the necessity of adequate prediction of ultimate strength and failure modes. The predictions based on fiber-reinforced polymer (FRP) design codes and guidelines were investigated and compared with the test results of five large-scale GFRP-RC squat walls with different failure modes. The results demonstrated that in the one code, the concrete contribution to the shear resistance should be considered, and in other design guidelines, the 45° shear crack–angle assumption should be modified for squat walls with different properties and should consider the increase in concrete shear contribution after initiation of the first shear crack. The confinement at boundary elements has been shown to improve significantly the ultimate flexural strength that should be integrated in the design.