For as long as there’s been construction, there’s been jobsite noise. As our understanding of how excessive sound can affect workers’ health has improved, greater efforts have been made to limit their exposure.
The Occupational Safety and Health Administration (OSHA) estimates as many as 22 million American workers may be affected by potentially damaging noise at their jobs. OSHA’s current permissible exposure limit is 90 decibels for workers putting in an 8-hour day, with the allowable time of exposure reduced by half for each increase of 5 decibels over the limit.
A study by the National Institute for Occupational Safety and Health found that the average 35-year-old construction worker has roughly the same hearing as a 55-year-old who has not been exposed to similar excessive noise. Hearing loss isn’t the only safety concern of a noisy jobsite, either. Too much noise could mean someone won’t be able to hear a warning from a coworker or the sound of a piece of heavy machinery backing up.
With these concerns in mind, companies in recent years have tried various new methods and technologies to make jobsites quieter.
New York City Mandates Use of Electric Jackhammers
Construction noise, particularly jackhammers wielded by road maintenance crews, is a familiar annoyance to any city dweller. Back in 2014, in response to a continuous public outcry over the sound levels, city officials began requiring workers to replace traditional pneumatic jackhammers with electric models. According to Time Magazine, such electric jackhammers have the same concrete-busting capabilities as conventional models but operate at around 10 decibels lower.
The New York Times also conducted an experiment on a construction site. It tested traditional jackhammers against the Hilti TE 3000-AVR, which has been produced since 2011. In the side-by-side comparison, the Times found the electric version had run 15 decibels quieter. The noise expert told the paper that each 5-decibel reduction in sound was the equivalent to halving the noise level of a piece of equipment.
Hydrodemolition to Reduce Construction Noise Pollution
Demolition is noisy work; it’s a fact. But, believe it or not, even demo projects can be made quieter with the right technology. Hydrodemolition, also known as hydroblasting or hydromilling, is a method of surface preparation and concrete removal that has been rapidly growing in prominence.
The method uses high-pressure water, rather than conventional pneumatic tools, to remove old concrete. Hydrodemolition usually requires a remote-controlled robot supplied with water from a high-pressure pump, although autonomous robots are also available. According to the automated concrete removal services provider Conjet, hydrodemolition offers many advantages beyond just noise reduction. The method creates no vibrations, dramatically reduces the amount of dust and debris produced, and preserves the rebar underneath. The company estimates hydrodemolition can be done up to 20 times faster than demolition using pneumatic jackhammers.
For Construction Pros writes that although hydrodemolition robots are usually around 10 decibels lower than standard methods, additional considerations are needed. Otherwise, the high-pressure, diesel-powered pump supplying water to the robot may end up being just as loud or even noisier than the robot itself. One method to accomplish this is known as hoarding. It requires temporarily surrounding the work area with solid barriers to reduce the noise escaping from the jobsite. However, that setup takes time and resources. An even quieter and more efficient method involves high-pressure pump systems that include built-in enclosures, for instance, shipping containers outfitted with additional sound-absorbing properties. Exhaust escaping the enclosure can be further silenced with a muffler.
Making Heavy Machinery Quieter
Another frequent producer of excessive jobsite noise is heavy machinery and other equipment, which can reach decibel levels up to 115 dB, according to the Centers for Disease Control and Prevention (CDC). This can be mitigated in several ways.
For instance, new machinery tends to be a lot quieter than older equipment with worn out parts. Vehicles powered by electricity can operate nearly silently. However, there’s something to be done even if purchasing a new fleet of silent-running electric vehicles isn’t in the budget. Existing machinery can be retrofitted cheaply and easily with new mufflers or additional sound dampening materials, The Laborers’ Health & Safety Fund of North America writes. The fund also recommends asking manufacturers how loud their equipment is and factoring that into any purchasing decision.