Specifications to Reduce Bridge Deck Cracking

This article reports on a pooled-fund study that is being implemented in two phases under the direction of the Kansas Department of Transportation in conjunction with 18 other state departments of transportation and the Federal Highway Administration to construct 40 low-cracking, high performance concrete (LC-HPC) bridge decks in Kansas and partner states. To reduce cracking in concrete bridge decks, new specifications for low-cracking, high performance concrete were developed. The authors discuss the specifications, which require the use of a concrete with low paste content, low slump, moderate water-cement ratio, controlled placement temperature, elevated air content, and optimized aggregate gradation. These decks, which did not contain any supplementary cementitious materials, are now being evaluated and compared with conventional decks for cost and cracking performance. In the second part of the article, the authors review construction and post-construction processes and how they improved after lessons learned during the first phase of the project. They conclude that the implementation of LC-HPC specifications has worked in the field by producing decks with less than 10% of the cracking found in traditional bridge decks.