The Georgia Department of Transportation maintains a network of roads and bridges that carry some of the highest traffic volumes in the country, and often employs accelerated bridge construction products when rehabilitating its structures, as was the case in the recent rehabilitation of two eastbound and two westbound structures spanning the Alcovy River and Alcovy Watershed on Interstate 20, in Newton County just 35 miles east of Atlanta. This stretch of I-20 is a major route for more than 40,000 commuters per day, connecting Atlanta to Augusta and other popular eastern destinations. A viable detour route was not available to permit full bridge closures, so with the interest of the traveling public in mind the DOT required staged construction with the bridges fully open to traffic during peak travel times. In late 2013, the Georgia DOT awarded Massana Construction, Inc. a rehabilitation contract that included deck replacement, painting and other miscellaneous repairs to the four bridges.
Realizing the highest traffic volumes on this stretch of I-20 occur during weekends and holidays, the DOT, in effort to eliminate disruptions to weekend travelers, permitted weekday lane closures from 12:00 noon on Sunday until 10:00am on Friday only, with a $500/hour penalty charged to the contractor for late opening. To reduce weekday traffic congestion during construction, only one lane could be closed at any time on either the eastbound or westbound structures. Staged construction with short five-day closures was possible using precast grid reinforced concrete bridge deck panels, with two unique details utilized to connect the panels. One detail used a simple shear key splice, and the other used overlapping shear studs in the negative moment regions over the piers to develop tension in the panels. Rapid setting concrete was used for the closure pour areas over the supports and between panels, allowing traffic to be put back on the bridge less than one day after the pour.
The 208 galvanized grid deck panels were supplied by Bailey Bridges, Inc., a fabricating member of the Bridge Grid Flooring Manufacturers Association (BGFMA). The panels were precast less than 60 miles from the project site at Massana Construction’s precast yard in Fairburn, Ga. The precasting operation required very little formwork, keeping costs to a minimum. Massana was able to replace nearly 34,000 square feet of bridge deck from April 21 to Aug. 11, 2014. In this 17-wk timeframe, four weeks were lost to holidays and interceding weather, and another four weeks were required for MPT work, leaving only nine closure periods for deck replacement. According to Steve Roeser, project manager for Massana, “There was only a short learning curve needed when working with the precast grid deck panels. After the first few weeks we were running at full speed, replacing roughly 5,000 sq ft of deck (26 panels) in each closure.”
