Sustainable Pavement Design - Delivering Sustainable Options Considering Existing Materials and Pavement Lifecycle by Trent McDonald.

Abstract

With a drive toward sustainability and pavement longevity, there is an ever growing evolution in pavement materials and design concepts. In this paper, Pavement Management Services has proposed four mechanistic-empirical design options for a failing road in Moreton Bay Regional Council (MBRC) in Queensland, Australia in 2016. Of the four pavement designs, two consisted of conventional asphalt and granular pavements, whilst the other two consisted of a more sustainable - foamed bitumen treatment and a perpetual pavement design.

An extensive investigation was carried out on the pavement including Falling Weight Deflectometer, boreholes, and geotechnical testing; which was used to assess the in-situ conditions of the pavement and material properties. The investigation allowed the formulating of the foamed bitumen and a perpetual pavement design alternatives, where the foamed bitumen option considered incorporating the existing materials to into the rehabilitation treatment, whilst the perpetual pavement considered a new three layered asphalt pavement for an extended lifecycle. The perpetual pavement incorporated a three layered asphalt coarse to utilise the different characteristics of the mixes and to limit strain at critical locations within the pavement, thus controling the mode of failure. By doing so, the pavement was set to last in excess of 40 years without structural improvement and minimise pavement life cycle cost.

The paper outlines the investigation and methodologies and pavement design options used in the investigation and design process. The pavement designs have been proposed and accepted by council, and are awaiting a final decision in the design option for tendering process.