Modelling Post-tensioned Precast Concrete Segmental Girder Bridges with Keyed Joints – Preliminary Results

Abstract

Precast concrete segmental bridges (PCSBs) have been the most common design technology used in the last decades. It is widely recognized that segmental bridges have better durability, lower life-cycle costs and higher quality for maintenance than other types of bridges. PCSBs with externally prestressed tendons have become very popular in construction because of economical and safety reasons, fast and practical construction, and outstanding serviceability. Moreover, external tendons technique is widely used because it allows to inspect the cables and to replace them or to reinforce the tendons in case of damage while such kinds of actions are difficult to be taken in case of internal prestressing. Therefore, box section is the most common solution due to its aesthetic appeal and elegance that reduces the environmental impact as well due to the convenient maintenance for the tendons. Besides, the hollow concrete box segment can be used for service/electrical cable ducts for bridges. However, there is lack of reliable computational model for analysing behaviour of post-tensioned PCSBs. This research investigates the behaviour of PCSBs with dry keyed joints and external tendons up to failure with the use of finite element method which is validated by comparing experimental results. Deflection, joint opening, tendon slip, stresses of the tendons and the concrete are obtained from numerical analysis with recommendation on further development towards a more accurate numerical model for PCSBs made.