Watch Utah Highway Workers Blast Away Bridge Concrete With High Pressure Water
Utah DOT / YouTube
Hydro-demolition is being used on a roadway rehabilitation project on Interstate 215, near Salt Lake City. Here's how it works.
To blast away old bridge pavement, workers on a Utah highway project have been using high pressure water—a technique the state’s transportation agency says saves time and money.
Hydro-demolition, as the process is known, is being carried out on a $105 million project along Interstate 215, in western Salt Lake County. The project is one of the first times the Utah Department of Transportation has employed the tactic for bridge deck reconstruction.
The equipment involved can spray water with up to 36,000 pounds per square inch, or psi, of pressure. Household pressure washers a person might use to clean their car or sidewalk tend to put out between 1,000 and 3,000 psi , depending on the model.
According to the state’s DOT, hydro-demolition allows for a level of precision removing unsound bridge concrete not afforded by more traditional techniques, and leaves intact other parts of the structure that are still in good shape. This can result in time and cost savings.
“While we are reconstructing I-215 with all-new concrete pavement, we also want to preserve what we have where possible,” said project manager Oanh Le Spradlin in a statement.
About 15,000 to 17,000 gallons of water gets used in a 10-hour shift by the process. Wastewater is collected, treated and recycled, according to Utah DOT. Pavement removed from the bridge deck is ground up, and can be reused as base-material on road projects.
Hydro-demolition has roots in the 1980s in Italy and Sweden, according to a 2014 report written by a Missouri DOT bridge inspection engineer. Patrick Martens, the author, noted in the report that the process “has unlimited potential in changing the course of bridge deck preservation.”
He went on to write that, in his 26-years of doing bridge inspections and maintenance, “one of the most fascinating processes I have encountered is the process of hydrodemolition.”
On the Utah project, hydro-demolition is being used to remove about 3 to 4 inches of concrete bridge decking, so that it can be replaced with fresh material.
The work now underway in the Interstate 215 corridor began in early May and is expected to take until fall of 2017 . It is taking place along roughly eight miles of the highway.
Interstate 215 is considered one of the most important corridors in Salt Lake County, which encompasses Salt Lake City, with more than 100,000 vehicles passing through it per day.
Bill Lucia is a Reporter for Government Executive’s Route Fifty and is based in Washington, D.C.
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