Seven 7m long reinforced concrete T- beams strengthened with prestressed CFRP sheets are tested under the simulated actual working conditions. T he equipment for prestessing CFRP sheets is developed and designed also . Several parameters, including the amount of strengthening CFRP sheets, the prestressing degree, the reinforcement ratio, two- stage load and the strengthened beam with or without prestressed tendon, are studied in the test program. The momen-t curvature curves of the tested beams which are acquired with a beam simulating numerical program are corresponded with the test resluts well. The prestressed CFRP sheets strengthening can increase the load capacity and decrease the deflection and the width of crack. The practicability of the technique of the prestressed CFRP sheets strengthening is proved.
[2] Garden H N,Hollaway L C,Thorne A M.The Strengthing and Deformation Behaviour of Reinforced Concrete Beams Upgraded Using Prestressed Composite Plates.Materials and Structural,1998.33:247~258;
Less J M,Winistorfer A U,Meier U.External Prestressed Carbon Fiber-Reinforced Polymer Straps for Shear Enhancement of Concrete.Journal of Composites for Construction,2002(12)249~265;