Experimental Investigation of Short and Slender Rectangular Concrete Columns Reinforced with GFRP Bars under Eccentric Axial Loads

Abstract

In this paper, the experimental behavior of short and slender concrete columns reinforced with glass fiber-reinforced polymer (GFRP) bars under eccentric compression loading is presented. A total of 10 large-scale concrete column specimens with a rectangular cross section (205 × 306 mm) were tested under a single curvature condition with equal load eccentricities at both ends of the column. Four slenderness ratios of 16.6, 21.5, 39.7, and 59.5 and two reinforcement ratios of 2.78% and 4.80% were considered. The results showed that no crushing of GFRP bars occurred prior to concrete spalling. The columns were able to sustain load, moment, and deformation after the concrete spalling up to the crushing of GFRP bars in compression. The latter was attributed to the contribution of GFRP bars in compression. An analytical model was also adopted to predict the behavior of the test specimens and to evaluate the effect of load eccentricities beyond the one considered in the experimental program. Also, the flexural stiffness and moment magnification factor obtained from the experimental program were compared with those calculated using equations from the literature. The results showed that most of the equations underestimated the flexural stiffness and the magnified moment.