Life cycle inventory for pavements - a case study of South Africa

Abstract

For many years, South African road authorities have taken measures to reduce costs of road construction, vehicle operating costs as well as road fatalities while enhancing road performance to improve the sustainability of pavement infrastructure. These efforts have commonly been realised through reducing economic costs evaluated using life cycle cost analyses (LCCAs). However, efforts to address sustainability are incomplete if environmental and social impacts are not considered. A life cycle assessment (LCA) is an approach which can quantify the environmental and social impacts of pavement infrastructure provision. At present, no such protocol is in place in most countries including South Africa. This paper proposes a framework for the development of an LCA model, by documenting the life cycle inventory (LCI) for common pavement materials and construction activities.

This LCI acts as a building block to the LCA by evaluating primary flows related to the supply chain of pavement materials and construction activities in South Africa. The primary flows are represented by indicators which quantify impacts, including key indicators for emissions to air and water, energy- and water-use. The LCI further provides indicators for novel and recycled materials which may greatly assist in evaluating the sustainability of pavement options. A worked example is provided to demonstrate implementation of the LCI.

The approach is envisioned to function as the first version of a living protocol that will be improved on through further research. Although the primary target audience is South African road authorities, the approach can be adapted for any country.