PREVENTION OF CRACKS IN CONCRETE BRIDGE DECKS: REPORT ON SURVEYS OF EXISTING BRIDGES

Cracking in newly constructed concrete bridge decks is a concern in Pennsylvania. This project aimed at examining the performance of existing bridge decks in Pennsylvania. Transverse cracking was identified as the prevalent type of cracking. The main cause of transverse cracking noted in the bridge decks was concrete shrinkage. Concrete shrinkage was the result of loss of heat of hydration during curing (thermal shrinkage) and loss of mix water after curing (drying shrinkage). Recommendations regarding aggregate type, cement type and content, and cold weather curing of concrete are provided to reduce shrinkage and minimize cracking.