Study on eccentric behavior and serviceability performance of slender rectangular concrete columns reinforced with GFRP bars

Eccentric loading tests were performed on six full-scale glass fiber-reinforced polymer (GFRP)-reinforced concrete (RC) slender rectangular columns. The strain of the GFRP bar and concrete, the lateral deflection, and the flexural cracks width were measured at different load levels. The results indicate that under service loads, the lateral deflection and the flexural crack width of some specimens do not satisfy the serviceability criterion. At the peak load, the curvature range of the GFRP-RC slender columns is very close to that of typical GFRP-RC beams under flexural failure. This indicates that similar to GFRP-RC beams, excessive deflection and flexural crack widths may occur in eccentrically loaded GFRP-RC slender columns under service loads. In addition, an analytical model based on the well-known numerical integration method is presented to predict the load versus deflection relationship of eccentrically loaded GFRP-RC slender columns. Then, using the predicted results for the load versus the lateral deflection relationship, an analytical model is presented to predict the crack width of columns considering the bond-slip and tension-stiffening effects. These two models are found to reproduce the experimental results with satisfactory accuracy, which verifies that the two models can be used to predict the eccentric behavior of GFRP-RC slender columns.