External CFRP repairing of pretested beams reinforced using prestress rebars

Abstract

This paper presents experimental and theoretical investigations on flexural CFRP strengthening/repairing of pretested (i.e., damaged) beams reinforced using prestress rebars. Six beams were fabricated and tested under a four-point bending system to failure. The internal longitudinal tensile and transverse steel reinforcements of these beams were reinforced using prestress and mild steel rebars, respectively. After the application of load, these pretested (i.e. damaged) beams were repaired and tested using externally bonded Carbon Fibre Reinforced Polymer (CFRP) reinforcement. This study investigated the effects of number of CFRP plies, three different grades of concrete, and wrapping layouts. The results confirm that the CFRP repaired beams reinforced with prestress rebars efficiently increased the flexural capacity, however the trend of ductility was inadequate as in damaged-unstrengthened beams. Experimental results show that the flexural capacity of the repaired beams increased to a maximum enhancement of 172.4% over the damaged-unstrengthened beam. It was experimentally observed that CFRP repaired beams with low grade of concrete could provide better performance as compared to higher grades of concrete. The comparison of experimental and theoretical results had good agreement for higher grades of concrete, whereas, in case of low grade concrete, the experimental results were relatively greater than the theoretical results.

Development of a Prestressing CFRP Laminate Anchorage System and Bridge Strengthening Application

“…Compared to products bonded with multiple layers of carbon fiber sheets, products bonded with carbon fiber laminates have better assured quality. ey can withstand load more evenly and bring the strength of carbon fiber laminates into full play [10][11][12]. Carbon fiber materials are significantly advantageous in structure strengthening because of their high strength, low density, and corrosion resistance.…”

Effect of basic design parameters on IC debonding of CFRP-strengthened shallow RC beams

“…The former debonding mode has been studied extensively in the last decades [14][15][16] leading to significant contributions to the understanding of this kind of failure. On the other hand, even with the considerable studies [17][18][19][20][21][22][23][24] that have been conducted on the latter mode, IC debonding mode of failure is still not yet fully understood. The significance of IC debonding was examined experimentally by Sebastian.…”

An Experimental Study on Concrete Flat Slabs Prestressed with Carbon Fibre Reinforced Polymer Sheets

“…CFRP tendons are the FRP material used in concrete structures with the best prospects because CFRP tendons are regarded as the replacement for steel bars in steel reinforced structures. Currently, CFRP sheets and CFRP plates are used for structural reinforcement more commonly than other materials [3,4]. First, CFRP sheets and CFRP plates are relatively easy to produce.…”

“…Second, repairing and reinforcing the existing structures worldwide represent a large guaranteed demand for CFRP sheets and CFRP plates, which will also help to maintain relatively low prices for CFRP sheets and CFRP plates for the foreseeable future. Hence, researchers from several countries have conducted studies on CFRP sheets and plates, which have contributed to the continuous improvement and perfection of the production 2 Advances in Materials Science and Engineering processes [3,5]. According to the literature, 95% of the CFRP sheets and plates are used to strengthen and reinforce existing structures worldwide, while CFRPs are directly used as structural materials only in trial experimental studies.…”