Deflection of GFRP-reinforced concrete beams

Abstract

This paper presents an investigation of the performance of concrete beams reinforced with glass fiber-reinforced polymers (GFRP) under short-term loading. A total of six specimens with rectangular cross-sections (75 mm in height and 150 mm in width) were tested under a four-point bending test to failure. Each specimen was reinforced with two GFRP bars with diameters of 8 mm. The results of this study demonstrated the behavior of GFRP-reinforced concrete members and a validation of the available calculation methods for the deflection of these members and assumed possibilities of the use of a GFRP reinforcement over the long term. The results of the study presented show a very good agreement of an experimentally measured and theoretically calculated instantaneous deflection when using the approaches in the European and American standards. In calculations of long-term deflections, the results are highly inconsistent and seem to be quite overestimated in some cases. The study shows the necessity of real-time long-term measurements to demonstrate the real deformations to be assumed during design of structures reinforced with GFRP reinforcement.