Experimental Study on Strengthening Effect of High Modulus CFRP Strips with Different Adhesive Length Installed onto the Lower Flange Plate of I Shaped Steel Girder

Abstract Recently, number of steel bridges required to be strengthened to reduce working stress due to deterioration and updated design live load is increasing in Japan. Then additional steel plates are welded and bolted to these existing steel bridges in ordinary cases. However such conventional strengthening techniques have room for improvements onto construction workmanship. Then, experimentally investigated in this study is strengthening effect of high modulus CFRP strips installed onto the lower flange plate of I shaped steel girder. 6 specimens with different adhesive length are used in the bending tests. Also a method to prevent the strips from debonding at the both ends is proposed and investigated in the test. Then, the effectiveness of the CFRP strips strengthening and the debonding prevention method are discussed based on the experimental results.