Study on Repair and Strengthening of Steel Girder End with Section Loss Using CFRP Members Bonded by VaRTM Technique

Vacuum assisted Resin Transfer Molding (VaRTM) as a composite fabricating technique can be used to apply Carbon Fiber (CF) sheets on cross section loss of steel structures. The repair operation work has been proven to be very efficient and convenient even on complex shapes of structures due to the flexibility of this method. This paper deals with repair and strengthening of steel girder end with section loss using carbon fiber reinforced polymer (CFRP) members bonded by VaRTM technique, experimentally and analytically. The section loss is 100 mm of the lower end of web and vertical stiffener in the steel girder with the depth of 800 mm and section loss ratio is 100% in the web, 50% in the vertical stiffener, respectively. In the case of repair, CF sheets were placed in the area of section loss. In the case of strengthening, the partial CF sheets and three-dimensional CFRP members were placed in the web panel. The number of laminated CF sheets and the direction of arrangement were used as parameters. The arrangement of CFRP was parametrically examined by FE analysis and four optimal arrangements were selected. Moreover, three point bending load tests were conducted to confirm their validity. As a result, steel girder end with section loss can be repaired and strengthened by applying CFRP members using VaRTM technique.