Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/816123
EquipmentWorld.com | May 2017 69 www.mobilebarriers.com IMPROVE SAFETY. SAVE TIME. REDUCE SETUP, LANE CLOSURES & CONGESTION Highly mobile with power, lights and other options including crane and bucket. For right or left work at lengths to over 100'. Carries materials and supplies up to 85,000lbs. For purchase, lease or rent. BaileyBridge_BR0513_PG14.indd 1 4/23/13 9:32 AM DOTs push progress State departments of transportation across the country have been work- ing in recent years on their ABC techniques. Many of these efforts have centered on building super- structure components in temporary staging areas next to the bridge being replaced. The Rhode Island Department of Transportation, for example, replaced two bridges last Septem- ber, the East Shore Expressway Bridge and the McCormick Quarry Bridge, using this slide-in method. Each was completed in an 80-hour period in which the roadways were closed, mostly during weekends to limit traffi c impact. These moves, along with other work that did not impede traffi c, cut construction time by about a year. And Atlanta commuters will be glad to know GDOT has a long ABC resume. The agency has worked for a decade to develop multiple ABC techniques to boost bridge construction. DuVall says that in 2005 the agency fi rst used Exodermic panels – also known as composite, unfi lled steel grid panels – to rapidly replace decks on two bridges on Atlanta's I-285. During construction over a series of weekends, the contractor only closed lanes, rather than the entire section of interstate, to keep traffi c open. "This is not uncommon. It's been used around the country, but this was our fi rst use," DuVall says. "Since then, we've used it in a few other places around the state as well. That really proved that do- ing the construction with the traffi c could be a real benefi t to the state." Last summer, GDOT replaced a bridge on S.R. 211 about 50 miles northeast of Atlanta using full-depth precast deck panels with ultra-high performance concrete (UHPC) closure pours. This was the fi rst time time the agency used UHPC in these connections, and its success led GDOT to add it to other projects in design to help accelerate those bridges. The project required only 60 days of road closure, with actual work on the structure lasting just 41 days. "Sixty days was a huge win for us," DuVall says. "It's not just prov- ing it to ourselves and to the con- tractor you can do it quicker, but it's also proving it to our fi eld people. We had to convince them this is something we can do." Duvall says knowing the total working-days fi gure will help plan- ning for similar projects. "If I know I've got a similar bridge, I'm not going longer than 40 days, and honestly if we really want to get it done quicker, we just need to tell the contractor to reduce the time," he says. "It should be that simple." Determining savings on the S.R. 211 project was more complex, Du- vall explains. For a single span bridge in Georgia, replacing just the bridge costs about $100 per square foot.