The Utah Department of Transportation (UDOT) is using water to help speed up work on its I-215 reconstruction and renovation project, saving the agency both time and money.
UDOT is using an innovative system of high-pressure water jets to refurbish bridge decks on the ‘215 Renewed’ project. This is one of the first times that UDOT has used this hydro demolition process to reconstruct a bridge deck, and the first in the Salt Lake Valley. Hydro demolition will allow crews to be more precise while refurbishing the bridge, which saves time and money.
Hydro demolition is being used to remove the top few inches of the pavement on two I-215 bridges (3500 South and 3800 South), leaving much of the pavement and the reinforcing steel intact. Other demolition methods could potentially cause structural damage and require more extensive repairs, extending the schedule and increasing costs. Using hydro demolition to remove and replace the concrete bridge decks will extend the life of the bridges by 15 years.
The hydro demolition process uses a machine that moves over the bridge, spraying water to remove the top 3-4in (7-10cm) of the bridge deck. The machine sprays water at up to 36,000 PSI (lb-force per square inch) or 2,482 bar, which is up to 24 times more powerful than the average domestic pressure washer. After a few passes, a cleaning crew comes through and sucks up all the water and material with a vacuum. The vacuum uses a water jet to dislodge debris and then suck it up, in a similar technique to a dental hygienist performing a teeth cleaning. The hydro demolition machine sprays 15,000-17,000 gallons (56,780-64,345 liters) per 10-hour shift, which is about the amount needed to fill the average in-ground domestic swimming pool. The water is collected on-site, pumped into tanks, filtered, and then sent to a treatment plant and recycled back into the system. All of the vacuumed materials are ground and reused as hardcore road base on construction projects.
Crews are making significant progress on the I-215 reconstruction, UDOT’s largest project of 2016. During construction, all four lanes of traffic will remain open in each direction during the morning and evening commutes. Most work, along with the necessary lane restrictions, are scheduled at night to reduce delays for the more than 100,000 cars per day traveling this busy section of I-215. Work on the I-215 renewal project is scheduled for completion by the autumn of 2017.
“While we are reconstructing I-215 with all-new concrete pavement, we also want to preserve what we have where possible,” said Oanh Le Spradlin, UDOT project manager. “Utilizing an innovative tool like hydro demolition helps us accomplish that on several bridges without spending the money on a complete rebuild.”