Sustainable environmental and financial outcomes resulting from doubling the life expectancy of asphalt roads

Abstract

There are long-term sustainability and financial benefits for Councils in adopting intelligent intervention strategies and treatments to extend the life of their roads. Given the current environment of the United Nations sustainability goals, climate change, and the public acceptance of the circular economy, there is growing emphasis in going beyond the traditional approach of maintaining Council’s asphalt roads by resurfacing. Reuse of asphalt (RAP) and recycling of materials are now a common process but increasing the service life of existing asphalt has been little discussed. Asphalt rejuvenators have been available for many years, However, by the mid 2000’s ‘Rejuvenation’ treatments were no longer applied on Australian roads due to increasing complaints from residents unable to access their properties due to extended curing/drying time of ‘Rejuvenation’ treatments and claims from road users due to accidents resulting from skidding/loss of friction. There is now a place in the asset managers tool kit for Penetrative Asphalt Preservatives. These are not rejuvenators, but protective coatings to preserve the bituminous binder from further environmental deterioration which results in an extension of life. This paper then presents two case studies. One of a proven international process that preserves the visco-elastic properties of the bituminous binder to enable Councils to double the life of the asphalt surfacing on all their roads. It will provide Road Asset Managers with an overview of the long-term benefits and performance of roads treated in the UK and Europe with a Penetrative Asphalt Preservative (PAP) since the early 2000’s. In order to transfer this technology to Australia it underwent examination by Transport Infrastructure Product Evaluation Scheme (TIPES), managed by ARRB, and has been shown to work in Australia, too. The second case study concerns the long-term sustainability and financial benefits for Councils of adopting intelligent intervention strategies and treatments to extend the life of their roads. The traditional approach of maintaining Council’s asphalt roads by resurfacing is increasingly not financially sustainable. These two case studies are then combined to demonstrate that merged with a sound treatment strategy, increasing the service life of a material - before then reusing or recycling - presents significant savings.