The Maryland Intercounty Connector (ICC) is a $1.5 billion, 17.9-mile project that will link existing and proposed development areas between the I-270/370 and I-95/U.S. 1 corridors and serve approximately 1.6 million people in the Washington, D.C., metropolitan area.
MD 200 Constructors, a joint venture of Kiewit, Corman and Wagman, is responsible for the largest section of the project, whose construction involved mass-concrete pours for numerous bridge columns and caps. A key technology assist on the project came from the Engius intelliRock II Concrete Temperature Monitoring System , which enabled remote, real-time monitoring of each pour, saving hundreds of man-hours. Temperature data provided by this system prevented overheating of the concrete and reduced fuel costs. These savings of time and money translated into improved concrete quality.
For the project’s cold-weather pours, Process Control Manager Sean McAfee had to maintain the concrete temperature above 50°F for seven days to comply with ACI 306r winter curing specification. Additionally, there was a contractual requirement to review and log the temperature differential on these pours in four-hour increments for seven days following each pour. To satisfy this requirement, six intelliRock temperature loggers were placed in each column pour and three in each cap.
The real-time, wireless temperature data monitoring provided by intelliRock allowed anyone on the job, including the owner, to check temperature compliance at any time. Even in poor weather, the project team was able to monitor temperature in the placements from home or any Internet-connected PC. This capability was not only convenient but also much safer, because crews did not have to go to each pour, climb ladders, remove blankets and check temperatures manually or with handheld devices.
Remote monitoring of intelliRock saved an estimated 1,000 man-hours on the project. Further savings were realized by using intelliRock temperature data to accurately estimate the amount of heater fuel required to maintain the concrete at the desired temperature. This approach lowered fuel consumption and prevented overheating the concrete.
“If anything went wrong with a pour, we knew about it immediately because of intelliRock, not the next day,” said McAfee. “This allowed us to get right on the problem and fix it. Having live data helped us improve the quality of the concrete, because we could make changes to heaters and blankets to keep our placements within specifications on temperature differentials. The system also helped us establish great owner relations. Their trust in the project temperature data was never an issue with the owners because the intelliRock system is locked.”
McAfee’s advice for doing mass-concrete pours is simple. “For the first bridge on this project, we were using a handheld temperature reader and writing the data on a pad. This wasted our people’s time. Start out with the right monitoring equipment. When you understand how live temperature data helps improve concrete quality and owner relations, the intelliRock system makes a lot of sense.”
