Assessment of warm-mix asphalt concrete containing sub-products as part of aggregate blend

ABSTRACT

The study compares warm-mix asphalt concrete (WMA) and a traditional hot mix asphalt concrete (HMA), evaluating permanent deformation, fatigue, stiffness modulus, and water sensitivity. The cost (construction only) differences are also addressed. Three WMA blends were prepared. One WMA was manufactured with the stand alone organic wax and incorporated 60% of recycled concrete aggregate (RCA). The other two used organic wax embedded in cellulosic fibres, one of them incorporated 35% of reclaimed asphalt pavement (RAP), and the other had no added sub-product. Trial sections were constructed with plant-produced mixtures, laid and compacted with conventional equipment. When considered a global indicator representing mixtures mechanical behaviour involving deformation, rutting, fatigue and moisture resistance, the results showed that performance of WMA blended with RAP and RCA was similar to HMA, and the conventional WMA was 25% better. The construction process proved to be feasible for any WMA. The direct construction costs as compared to conventional HMA were 6% higher for the conventional WMA and 5–8% lower when WMA used sub-products. The use of these sub-products is aimed to find innovative approaches to be undertaken throughout the product lifecycle, from manufacture through reuse, with the goal of reducing waste going to landfill.

KEYWORDS:

• Warm-mix asphalt
• reclaimed asphalt pavement
• recycled concrete aggregate
• mechanical resistance
• construction process
• direct costs

Acknowledgements

This research project did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.

Disclosure statement

No potential conflict of interest was reported by the authors.