It’s been hard to conceptualise asphalt as an environmentally friendly material ever since Joni Mitchell first sung the line “they paved paradise and put up a parking lot” way back in 1970. However, Ms Mitchell may have felt about the subject, asphalt is one of the most environmentally sustainable, energy efficient, and low emission construction materials available on the modern market. Here are four key reasons why asphalt should be considered a green surfacing option.
1. Recycling and energy efficiency
Asphalt is one of the easiest materials to recycle and the asphalt industry in America reuses or recycles some 95 million tons every year. Other recyclables can also be used to create asphalt like asphalt roofing shingles, tyre rubber and glass. When concrete is laid on the road, the base layer can also be made out of rubberized recycled concrete.
Even when produced as a primary material, asphalt is incredibly energy efficient and requires about 20% less energy to produce than other surfacing materials like concrete. From a production perspective, recycled asphalt is produced at a number of locations around Melbourne, which eliminates most of the carbon emissions associated with long distance product transport.
2. Infiltration capability
Asphalt is porous and can be utilised to turn runoff into infiltration, which ultimately preserves and in some cases improves the hydrology of a site and reduces the need for detention baths. Another advantage of asphalt is that it does not leach once constructed, and poses no harm to the environment. In fact, asphalt is so environmentally sound that it is often used to line water reservoirs and water pipes for human consumption.
When an asphalt surface is properly installed it consists of a series of layers, and only the top layer ever wears out. In this way, asphalt is a perpetual surface solution, as it is only ever the top layer that needs to be replaced.
4. Low emissions
Although it was once responsible for substantial carbon emissions, the asphalt industry has revolutionised in the last twenty years and has managed to decrease their total emissions by 97% whilst increasing production by a stunning 250%. Today, asphalt producers are only considered minor sources of industrial pollution by environmental authorities.