Early age crack mitigation
The purpose of this project was to assess the cracking potential of lightweight bridge deck replacements. These bridge decks often utilize a large quantity of reinforcing steel, which can significantly restrain the concrete from shrinking. Frequently, regular cracking can be observed when high performance concrete mixtures are utilized for these applications. To address this cracking issue, this research assessed the potential reduction in shrinkage cracking through modifications to the mixture design. To do so, nine different mixtures were cast in a typical bridge deck configuration on top of a large steel restraining beam and monitored for stress development and cracking. The slabs were instrumented with acoustic emission sensors (shown in image) to detect the onset of damage and any subsequent cracking.