Evaluation of Cracking Performance of Bridge Decks in Minnesota

Abstract

Six bridge decks in Minnesota supported by steel girders were evaluated based on cracking performance. The decks included two constructed in accordance with Minnesota low-cracking specifications and four constructed in accordance with Minnesota standard specifications. Crack surveys were performed on the decks to determine crack densities and location of cracks. The cracking performance of the decks is compared with the performance of decks constructed on steel girders in Kansas in accordance with either the low-cracking high-performance concrete (LC-HPC) or standard Kansas specifications. The decks constructed in accordance with the Minnesota low-cracking specifications have lower crack densities than the decks constructed in accordance with the Minnesota standard specifications. At similar ages, the decks constructed in Minnesota in accordance with either the low-cracking or standard specifications have greater cracking than decks constructed in Kansas in accordance with the LC-HPC specifications and have greater cracking than a majority of decks constructed in Kansas in accordance with the standard specifications. The majority of cracks develop in the transverse direction, parallel to the deck reinforcement. Longitudinal cracks propagate from the abutments. Cracks are generally evenly distributed throughout the decks, although increased cracking is occasionally noted directly above the piers. Additional surveys will be needed to understand the progression of cracking over time.