Introduction of the Lateral Posttension Method for Prestressed Concrete Bridges

Abstract

This paper describes a simple, practical, and inexpensive way of anchoring and applying the prestressing force for posttensioning of the concrete bridge superstructures. It is technically named as the lateral posttension (LPT) method. In applying the proposed new method, cable tendons are initially placed straight inside an open preformed channel or external to the cross section of the girder web. The bottom of the preformed channel is cast to match the desired final tendon profile of the prestressing path. Both ends of the tendons are embedded in the end blocks to form a dead-end anchorage system once the concrete is placed and reaches the required strength. The prestressing force is then applied by vertically deflecting the cable tendons to the prescribed profile at the bottom of the channel and locking the tendons at deflected profile. The benefits of this method lie in its simple anchorage system and easy stressing operation, thus it offers a viable posttensioning alternative. Although, further research and testing are needed before this methodology can be implemented to practice, the concept of this method opens a door for the development of a posttensioning operation that is simple, practical, and inexpensive. The accessibility for the stressing routine inspection and final adjustments makes the LPT method very useful for bridge rehabilitation and retrofit construction.