Shear Cracking in Inverted-T Straddle Bents

Diagonal web cracking of inverted-T straddle bent caps has been reported with increasing frequency in Texas, triggering concerns about current design procedures for such elements. To address these concerns, this project was developed with the objectives of obtaining a better understanding of the behavior of inverted-T beams and developing strength and serviceability design criteria that will minimize such cracking in the future. A recently completed research project, Texas Department of Transportation (TxDOT) Project 0-5253, examined the application of strut-and-tie models to the design of rectangular bent caps. From that project, recommendations were made to the AASHTO Load and Resistance Factor Design (LRFD) specifications to improve the strength and serviceability behavior of bent caps. This project aimed to evaluate the applicability of the recommended provisions, which were calibrated for compression-chord loaded beams, to inverted-T, or tension-chord loaded beams.