The bridge assessment and rehabilitation programme has revealed that a number of bridges do not meet current standards. The most cost effective option for some is strengthening. One method of strengthening that has been used in many countries and has been found to provide an efficient and economic solution for a wide range of bridge types and conditions is external post-tensioning. The technique is growing in popularity because of the speed of construction and the minimal disruption to traffic flow. It has, however, found limited application in the UK both for strengthening and for new construction and, until recently, had only been used on a small number of structures. To assist the Highways Agency to update its Standards on externally post-tensioned bridges, TRL was commissioned to design, construct and test a quarter-scale model of a two-span, 80m long externally post-tensioned bridge. The paper describes the results of two load tests carried out on the bridge and considers how the results can be applied to the use of this technique for strengthening existing structures. (A)
Abstract