Curing practices to reduce plastic shrinkage in concrete bridge decks

The large, exposed area of concrete bridge decks makes proper curing critical and difficult. Plastic shrinkage cracks are common in improperly cured bridge decks. The objective of this research was to identify curing regimens that successfully reduce plastic shrinkage cracking. This was accomplished by surveying Arkansas Highway and Transportation Department engineers to determine the current construction practices on Arkansas bridge decks, documenting the curing of five bridge decks under construction, and studying the effectiveness of curing regimens in the laboratory. The survey responses show inconsistencies in the interpretations of the construction specifications that were also evident in the field study. Delayed curing, high evaporation rate, and increased girder deflection increased the likelihood of cracking in the decks. Inconsistent application of curing materials caused increased cracking in the laboratory study. Removing impediments, such as tined finishes, to timely curing and clarifying curing specifications would reduce cracking in bridge decks.