Abstract：Due to low utilization of high-strength properties and easy peeling failure of CFRP sheets,performance improvement of RC beams strengthened with nonprestressed CFRP sheets is usually limited. To ensure effective bonding,a tensioning and anchorage system of prestressed CFRP sheet was developed and the corresponding construction technology was also given. In order to verify the feasibility of the proposed system,experiments on T-section reinforced concrete (RC) beams strengthened with prestressed CFRP sheets were carried out. Based on the failure mode for the rupture of CFRP sheets,an analytical model was presented to predict the shear capacity of RC beams strengthened with prestressed CFRP sheets. The results demonstrate that the tensioning and anchorage system can produce the reliable prestressing forces for CFRP sheets and reduce the loss of prestress. Flexural failure signified by concrete crushing in compression zone was witnessed in tested beams strengthened with prestressed CFRP sheets,but anchorage device can prevent the peeling failure of CFRP sheet before the rupture of CFRP sheets. The prestressed CFRP sheets can significantly restrain the initiation and development of concrete cracks,and the shear capacity of strengthened beams can be greatly improved. The calculated results agree well with the experimental ones,indicating that the analytical model is effective in predicting the shear capacity of RC beams strengthened with prestressed CFRP sheets.
