Using warm mix asphalt on a provincial road project

This paper covers experience that is being gained in the use of Warm Mix Asphalt on a project in Kwa-Zulu Natal. Approximately 29 000 tons of Warm Mix Asphalt, produced using foamed bitumen technology and utilising 25% reclaimed asphalt, is used in the base on Inanda Road (P255), between Hillcrest and Waterfall. The paper explores the synergy of using reclaimed asphalt and Warm Mix Asphalt together in the mix, and the economic and environmental advantages that can be achieved. In particular it examines the foamed bitumen process that enables the asphalt mix to be manufactured, paved and compacted at temperatures at least 20 degrees C below those of conventional asphalt. The paper concludes that the Warm Mix Asphalt technology, combined with the incorporation of reclaimed asphalt, is appropriate both economically as well as environmentally where asphalt is used in the pavement layers.