FLEXURAL BEHAVIOR OF STEEL BEAMS STRENGTHENED WITH FIBER REINFORCED COMPOSITE PLATES

摘要

Fiber-reinforced polymer (FRP) has been becoming a very attractive material for strengthening steel structures in resent years. In order to evaluate the effectiveness of steel beams strengthened by externally-bonded FRP to the tension flange, this paper presents an experimental test to investigate the flexural behavior of artificially damaged steel beams strengthened with high-modulus carbon-FRP (FIMCFRP) plate and steel-wire basalt-FRP (SW-BFRP) plate, under the equivalent tensile stiffness. Three steel beams were tested in four-point bending under static loading. The load-carrying capacity, stiffness and failure modes were discussed in this paper. Test results showed that the use of HM-CFRP and SW-BFRP could increase the yield load, serviceability limit load and ultimate load effectively. The stiffness, especially the post-yielding stiffness, can be also enhanced significantly and the midspan deflection could be reduced markedly, compared to the unstrengthened beam. However, compared to SW-BFRP, the HM-CFRP strengthened beam showed a more brittle behavior mainly due to the comparatively low ultimate strain of HM-CFRP plate.