GFRP Strengthening of RC Continuous Beams

Abstract

Strengthening structures through external bonding of advanced fibre reinforced polymer (FRP) composite is turning out to be exceptionally well known worldwide amid the previous decade on the grounds that it gives a more practical and in fact better option than the conventional procedures much of the time as it offers better strength, good fatigue resistance, low weight, corrosion resistance, easy and rapid installation along with minimal change in geometry of the structure. Although many in-situ RC beams are continuous in construction, there has been a limited research in the area of FRP strengthening of continuous beams. In the present study, an experimental investigation is carried out to study the behavior of continuous RC beams under static loading. The beams are strengthened with externally bonded glass fibre reinforced polymer (GFRP) sheets and also with unbonded GFRP using steel bolt system. Different scheme of strengthening have been employed. The experiment consists of six continuous (two-span) beams with overall dimensions equal to (150×250×2300) mm. All the beams will have similar longitudinal and transverse steel reinforcement. One beam was not strengthened and was considered as a control beam, whereas all other beams were strengthened in various patterns with externally bonded GFRP sheets and unbonded GFRP with end anchorage using the steel bolt system. The present study examines the responses of RC continuous beams, in terms of failure modes, enhancement of load capacity and load deflection analysis. The results indicate that the shear strength of RC beams can be significantly increased by gluing GFRP sheets to the shear face. In addition, the unbonded sheets with end anchorage also improved the cracking behaviour of the beams by delaying the formation of visible cracks and reducing crack widths at higher load levels.