PREMATURE FAILURE OF PRESTRESSED STEEL BARS

The details of two failures of prestressed steel bars are reported and a failure analysis is carried out using Linear Elastic Fracture Mecha nics: the fracture toughness was measured using two standardized proce dures and the pertinent stress intensity factor computed by numerical methods. The analysis of the failures show that the usual design requi rements for prestressing bars fail to warn against brittle failures if damage exists. Some procedures, based on the concept of damage tolera nce, are suggested to avoid similar accidents. (C) 1998 Elsevier Scien ce Ltd. All rights reserved.