Using high-tech demolition to increase productivity and safety in bridge work
by Lars Lindgren, president, Brokk Inc.
Out of 614,387 U.S. bridges, almost 40% are 50 years or older and 9.1% are in critical need of repairs. A recent estimate lists the U.S.’s backlog of bridge rehabilitation needs at $123 billion.
When infrastructure funding comes through, contractors need to be ready with the fastest, most productive options to take on the heavy, urgent workload.
More and more are turning to hydrodemolition robots and remote-controlled demolition machines as solutions. After experiencing worker shortages, increasing workers’ compensation claims and growing insurance premiums, the higher cost of the equipment starts to take a backseat. Remote-controlled and robotic machines provide more safety, productivity and efficiency for removing concrete around rebar than handheld tools, mini excavators and backhoes.
As an example, innovative hydrodemolition robots can remove as much as 800 square feet of bridge deck at a depth of 4 inches in just an hour, a fraction of the time it would take a crew of workers with jackhammers.
Unlike handheld tools and excavators with demolition tools, hydrodemolition robots virtually eliminate the possibility of microfracturing and unintended damage during bridge repair or rehabilitation. The 20,000-psi water jets target the bridge deck surface, quickly removing layers of concrete but leaving rebar unscathed and clean. There’s no need to spend extra time carefully avoiding rebar because the high-pressure water, though devastating to concrete, doesn’t damage the metal bars. The method also doesn’t cause vibrations, eliminating the possibility of microfracturing that could threaten bridge stability.
Alternatively, a remote-controlled demolition machine equipped with a breaker attachment and controlled by an operator and one spotter can break up 2 square feet of bridge deck concrete in 15 minutes. The same area in the same amount of time would require three workers with handheld tools.
Remote-controlled machines drop labor costs by 33%, accomplish the job faster and greatly reduce the risk of injury. Plus, it’s a lot easier to recruit young workers to run remote-controlled machines and hydrodemolition robots as opposed to handheld tools.
Until infrastructure funding is passed, the number of bridges in dire need of repair will continue to skyrocket. However, funding will eventually need to be addressed and these structures repaired before liabilities escalate. Contractors that prepare, plan and incorporate technology solutions into their business will be able to successfully, efficiently and profitably address these needs.