Effect of existing cracks in concrete bridge members strengthened by external post-tensioning

Loads on bridges are increasing due to rapid increases in the traffic volume as well as traffic load. At the same time, more than fifty percentages of the bridges are more than forty years old all around the world. Consequently deterioration of the existing bridges due to increasing traffic loads, exposure to adverse environmental conditions and structural aging has become a major problem today. These bridges are not able to cope up with the current traffic requirements and require either weight restriction, strengthening or even total replacement. Complete replacement is likely to become an increasing financial burden, if upgrading is a viable alternative. Several techniques have been developed to upgrade bridge structures. External post-tensioning is one of the widely use methods to strengthen bridges.