When you are casting around thinking about materials for a project, as a manager or purchaser for your organization, you can sometimes overlook one factor. That is the noise.
We generally accept, as asphalt paving contractors, that the working environment is going to be noisy and to a certain extent, so is the end product.
In short, roads and highways are not quiet places to be.
Noise pollution is increasingly being taken seriously by town and highway planners these days.
Concern for the effects that the noise from traffic will have on the local community is now considered carefully, before any new project getting the green light.
WHY IS QUIET ASPHALT NECESSARY?
As a professional asphalt paving company, you yourself have probably been aware of the environmental issues associated with road building and other types of construction.
But what you may not know is, that this is hardly a new worry for the authorities.
Because people have been complaining about the noise from the road for longer than you may be thinking!
In fact, as early as Roman times there have been laws in place, governing the traffic in public places.
The earliest piece of legislation relating to the noise that is associated with road haulage comes from none other than Julius Caesar!
Back in 44 BC, the emperor declared a ban on any wheeled mode of transport coming into Rome, between the hours of sunset and sundown!
This is because even back then, wheels clattering continually back and forth over the tiled streets made quite a commotion.
Fast forward two millennia and nothing much has changed!
In fact, it has only got worse.
But proposing a total ban on cars within city centers seems a little drastic.
This is where quiet asphalt can be of assistance.
WHAT IS QUIET ASPHALT?
Quiet asphalt is a type of asphalt road surfacing which, as the name implies, can reduce the noise from a highway or road.
Noise is created when car tires run over the asphalt – or other – road surfacing.
As an example, think about the sound that is emitted when you clap your hands together. Road noise is similar this.
The sound comes from the air, which is in between your two palms.
As you clap, that air is expelled at speed – and it makes a sound wave as it does so.
This is how the noise created when a wheeled vehicle drives over a road surface happens.
To go back to the hand clap experiment; this can be made quieter by opening the fingers of your hands and clapping with them apart.
Try it! The sound is muted.
So with quiet asphalt, the principle is applied likewise.
The usual dense graded asphalt is not used, and another mixture is created – this one with more gaps to let air out from the space in between a vehicle’s wheels and the surface of the road.
HOW QUIET IS QUIET ASPHALT?
Quiet asphalt can reduce the noise output from a road by up to seven decibels.
To put this into perspective, even a reduction of three decibels can be the same as doubling the distance between a listener and a sound.
WHAT ARE THE DISADVANTAGES OF QUIET ASPHALT?
Quiet asphalt is not without its imperfections.
It may be susceptible to damage by certain types of tires. In a Washington trial, it was found that the paving surface was compromised by the snow tires in use there, during the winter season.
Problems caused by wearing, especially in certain weather conditions are not the only potential issue.
It may simply be too expensive for a project. Depending on the budget available, quiet asphalt could prove too costly for many public purses.
This is why it tends to be reserved for shorter sections of highway, often in busy areas such as urban spaces.