ABSTRACT
In a research project in cooperation with the HILTI Corporation and SIKA Austria new strengthening methods for shear deficient bridges are being developed and tested. Although there exists a variety of techniques for subsequent strengthening of Reinforced Concrete (RC) structures, there is lack of knowledge on the efficiency of available shear repair methods. For practical reasons and with respect to typical cross sectional shapes. Carbon Fiber Reinforced Polymer sheets are usually bonded only to the sides or to sides and bottom of RC members in a U-shaped constellation. All specimens exhibited typical shear failure modes, flexural failure was never decisive. Both tested strengthening techniques exhibited a satisfying load enhancement in shear. With the Carbon Fiber Reinforced Polymer (CFRP) sheets the load gain was, depending on the number of sheets and layers, between 100% and 150%. The end anchorage of the CFRP sheets proved very effective so that either rupture of the CFRP or concrete failure in compression was observed.
