Experimental study of flexural behaviour of RC beams strengthened by longitudinal and U-shaped basalt FRP sheet

Abstract

Fiber Reinforced Polymer (FRP) composite products such as Carbon FRP (CFRP) or Glass FRP (GFRP) have been intensively studied for strengthening reinforced concrete (RC) and masonry structures. It has been reported that FRP strengthening is effective to enhance the structural load-carrying capacity. Basalt FRP (BFRP) is a promising material for the application to structure strengthening with its advantages of low cost, corrosion resistant and sound mechanical property, but only limited studies of using Basalt FRP to externally strengthen RC beam are available in the literature. This study is to experimentally explore the effectiveness of application of Basalt FRP to strengthen RC beam under three-point bending test. The damage modes and structural response of unstrengthened and BFRP strengthened RC beams were recorded and identified. The effects of various BFRP wrapping schemes, U-jacket anchorage and epoxy adhesives on the flexural capacity of RC beams were analysed and discussed. In addition, the formulae used to predict the flexural behaviour of RC beam strengthened by other FRP composites (e.g. CFRP/GFRP) were evaluated for their applicability to Basalt FRP strengthening.