Reinforcing and Rehabilitative Performance of Basalt Fibre Reinforced Polymers for Concrete Beams

摘要

This thesis presents the experimental results of laboratory testing conducted on full-scale concrete beams that are reinforced and rehabilitated with basalt fibre reinforced polymer (BFRP) products. The first study compares the structural behaviour of BFRP and steel reinforced beams. It was found that current design standards were able to predict the shear capacity of BFRP reinforced beams with varying accuracy. However, it was found that BFRP stirrups without proper bends did not prevent shear failure. Thus, proper BFRP stirrups need to be developed. The second study was on flexural strengthening and rehabilitation of concrete beams with BFRP composite. It was found that BFRP was effective in increasing or restoring service, yield, and ultimate load carrying capacity. It was also found that flexural crack widths are significantly reduced when BFRP is applied in flexure. However, interfacial debonding was still found to occur and was later corrected. The last study is one on the rehabilitation of shear deficient RC beams with BFRP composite. It was found that for the beam specimens with significant damage, the BFRP was effective in changing the mode of failure from brittle shear failure before yielding to flexural compression failure after yielding. Analysis of crack patterns with digital image correlation also revealed that the shear crack patterns were significantly changed between the damaged and rehabilitated specimen. It was also found that flexural crack widths are significantly increased in rehabilitated specimens. Thus, it is recommended that shear rehabilitation should be accompanied by flexural rehabilitation. Further research on more shear critical beams is also needed.