Assessment of crack width prediction methods for post-tensioned beams

Synopsis: A number of different crack width prediction equations have been proposed for use with partially prestressed concrete structures, but laboratory and field results for members with varying levels of post-tensioning are limited. A durability study at The University of Texas at Austin involved beams with varying combinations of bonded post-tensioning and non-prestressed reinforcement. This work included extensive crack width measurements at varied load levels. A follow-up study is now on-going at Penn State University to consider beams with a combination of pretensioning and post-tensioning (such as found in spliced girder applications). This paper presents and discusses the measured crack data from these studies, and compares the data to selected existing crack width prediction models. Comparison of measured and predicted crack widths did not reveal a single comprehensive crack width prediction formula for the range of variables considered.