ABSTRACT
Currently many bridges are considered inadequate for the current traffic loads due to various problems including rapid increases in the traffic volume and vehicle loads; exposure to adverse environmental conditions and structural aging. These bridges require either weight restriction, strengthening or even total replacement. Strengthening of such bridges is cost-effective for bridge engineers rather than total replacement. External post-tensioning is considered as one of the effective methods to strengthen bridge structures. Unlike flexural strengthening, the shear strengthening of existing structures using external post-tensioning has not been investigated adequately. The existing shear cracks may have substantial effect in shear strengthening of structural members using conventional external post-tensioning. Even most of the current design codes do not have provision for the existing shear cracks (except some guidelines recommend these cracks should be repaired prior to strengthening). This paper presents an experimental investigation on the effect of the existing shear cracks in such members strengthened with external post-tensioning.
