Baker Concrete Construction together with Vaughn Construction recently completed the larger of two mat pours for The University of Texas System, M.D. Anderson Cancer Center Administrative Support Building in Houston. Baker completed the first pour, 4000 cubic yards, on Dec. 12, at a rate of 570 cubic yards per hour. The larger second pour, completed Dec. 19, totaled 17,500 cubic yards, and 100 Baker co-workers pitched in to complete the job in less than 24 hours, at a rate of 730 cubic yards per hour. It is second only to the Venetian Hotel in Las Vegas as the largest mat pour in the United States.
With seven pump trucks, 97 concrete trucks, 1960 tons of installed rebar, and 2,400 man-hours, Baker was pleased with the results. "The planning really paid off," says Garrett Benson, project manager. "We used AutoCAD to help plan the job, and it worked well for us. And we completed the work with zero accidents or incidents, which is always our goal."
Although originally designed to be completed in three separate pours, the hurricane season amended that plan, and Jayco, the rebar subcontractor, worked overtime to complete the installation of steel. That efficiency enabled Baker to merge the second two pours and complete the job early.
The sheer scale of the second pour required detailed logistical planning from Baker, the Design Build Contractor Vaughn Construction, the Engineer of Record Haynes Whaley, the architect WHR, and consultants Earth Engineering, Ulrich Engineers, and Carrasquillo Associates Ltd.
For this job Baker managed a concrete temperature monitoring system that used thermo couplers to record the temperature of the material as it cured. The specifications called for the concrete mix to reach a temperature in the core no higher than 140º F. Furthermore, no two points in the mat could have a temperature difference of more than 40º F.
The thermo couplers were located throughout the mat at various depths, and were monitored twice a day for 28 days. The monitoring system allowed Baker to better control the curing process utilizing winter blankets despite the winter cold, and ultimately resulted in zero thermal cracks.
The M.D. Anderson Cancer Center Administrative Support Building is scheduled for completion in 2012, and Baker has already begun the concrete work for the structure.
For more, go to Baker Concrete Construction.