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otherwise the material will corrode and release the tyres creating an environmental

disaster. If done properly tyre reefs can form a great natural habitat for fish and other


Whole tyres can also be burned for fuel directly without the need for

shredding or processing, though this requires existing kilns to be modified (Clark,

Meardon, & Russell, 1993). These modifications to accommodate whole tyres can be

expensive and problematic due to the accumulation of incombustible products. If the

whole tyres are burned the ash contains lots of carbon material and steel slag which

can also be used in civil engineering applications such as mixing with concrete.

2.2.3 Rubber Asphalt

Rubber asphalt is an interesting application of tyre waste. Used to coat the top

layer of roads, rubberized asphalt contains at least 15% reclaimed tyre rubber by

weight. The rest of the asphalt is composed of regular asphalt cement and additives

(Rubber Pavements Association, 1998).

Besides the great benefit of recycling tyres, rubberized asphalt has plenty of

advantages over regular asphalt. These include reduced pavement thickness,

absorption of traffic noise (up to 85% has been noted), and longer road life. About

2,000 tyres are recycled per “lane mile”. The road life can be dramatically increased

which can help save costs in the long run. Furthermore, rubberized asphalt can be

recycled, used in diverse climates, and the emissions at the processing plant are

similar to that of regular asphalt (Rubber Pavements Association, 1998).


There are initial costs associated with rubberized asphalt. The processing

equipment is a significant investment, though once set up regular equipment can be

used to apply the asphalt to the road. Processing the waste tyres to create a fine


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