‘Green’ is increasingly the new gold standard in road building and local roads are set to get greener as road builders and associated organisations recognise the value of more environmentally friendly asphalt technologies.

This is according to Peet Eksteen, product sales manager for asphalt equipment at Osborn Engineered Products. The secret to this system can be summed up in one word, says Eksteen: “Foam!”

While the benefits of warm-mix asphalt – such as reduced energy consumption, lowered emissions and elimination of visible smoke – are well-known in the asphalt paving industry, he notes that many warm-mix production technologies have drawbacks.

“Many technologies for warm mix production rely on additives, special asphalt cement (AC), special procedures and/or special AC delivery systems to achieve low viscosities at low temperatures. The additives are expensive and add significant cost per tonne of mix. Through the use of foam alone, which is produced by mixing a small amount of water into the AC to create microscopic bubbles, ;Astec’s Double Barrel Green System allows for the production of warm-mix asphalt without the addition of costly commercial additives,” he states.

“The process uses water and there’s also no smoke and no smell because the light oils in liquid asphalt never reach boiling point. This system boasts the ability to run up to 50% of recycle mix with a standard grade of asphalt.”