Enhancing Performance with Internally Cured Concrete (EPIC²) promotes using internal curing to reduce shrinkage cracking in concrete. As discussed in our last issue, this form of early-age cracking in bridge decks makes the deck and the supporting structural elements susceptible to moisture and chlorides, which can lead to reduced deck and bridge service life. The search for ways to eliminate or reduce cracking has been a priority for DOTs for a number of years, and the Ohio Department of Transportation (ODOT), among others, have experimented with internally cured concrete (ICC) as a potential remedy.
In 2017, ODOT evaluated internal curing in State highway applications on a project featuring a pair of twin bridges in Mayfield Heights, OH. One was cast using traditional mixture designs as a control deck, while the other was cast using ICC. The bridges were surveyed 2 weeks after deck placement, where no cracks were detected in either bridge, and then again after 1 year. At that time, many cracks of varying widths were observed in the conventional concrete deck which could provide a pathway for chlorides and water to penetrate the deck and reach the reinforcement. In contrast, the ICC deck showed considerably less cracking. Additionally, ODOT observed that surface grooves of the deck were in much better condition. The ICC bridge deck outperformed the conventional concrete deck in all areas observed by the inspection team.
The internally cured concrete bridge deck showed significantly less cracking after 1 year of service. (FHWA Illustration, Data Credit: ODOT)
ODOT calculated the service lives of both bridge decks using a service life prediction model and the results indicate using ICC significantly increased the service life—from about 25 years to about 70 years. The analysis further demonstrated the ICC bridge deck’s total lifecycle cost would be nearly 30 percent less than the conventional concrete. Further annual inspections showed no signs of distress or cracking for the ICC deck, while the conventional concrete showed additional cracking.
Based in part on the success of this project’s results, ODOT undertook additional ICC projects and the State recognizes that the technology can save money through durability and longevity (enhancements) in pavements and bridge decks to meet 100-year design-life goals. For EDC-7, Ohio has set a goal for full institutionalization with eventual implementation of the technology on all DOT projects.
To learn more about how your agency can benefit from or implement ICC, visit the enhancing performance with internally cured concrete (EPIC²) team’s webpage. Subscribe to EPIC² email updates to stay informed, or contact Tim Barrett, FHWA Turner-Fairbank Highway Research Center, or Mike Praul, FHWA Office of Infrastructure, with any questions.