Unbonded Post Tensioned Concrete in Fire: A Review of Data from Furnace Tests and Real Fires

Abstract

The fire-safe design of concrete structures which incorporate post-tensioned prestressing tendons has recently been the subject of debate within the structural engineering community, particularly when unbonded post-tensioned (UPT) prestressing tendons are used. Despite several studies aimed at furthering our understanding of the response of UPT concrete structures in fire, many aspects of their response in real fires remain poorly understood. An exhaustive summary of available test data which have been used over the past five decades to generate fire design guidance for UPT concrete structures is given. Case studies showing the response of real UPT structures in severe building fires are also discussed. In both cases the intent is to highlight inadequacies in the current state of knowledge for UPT buildings in fire and to prioritize areas for future research.