The application of foamed tar technology to labour intensive construction of low volume roads

Abstract

Paper presented at the 21st Annual South African Transport Conference 15 - 18 July 2002 "Towards building capacity and accelerating delivery", CSIR International Convention Centre, Pretoria, South Africa.

The increasing scarcity of good road construction materials, combined with long haulage distances have necessitated the use of methods to improve substandard or existing materials through recycling. Although in-situ recycling has grown in prominence as a road construction alternative it necessitates the need for expensive equipment and expertise. Foamed tar provides a viable construction method for low volume roads through the application of labour intensive construction principles. Thus, the aim of this paper is to investigate the constructability of low-volume roads using foamed tar stabilisation with the assistance of the local community in infrastructure development. The paper will firstly introduce the subject of foamed tar stabilisation and address the perceived health aspects associate with this product. The construction of the foamed tar base course will be discussed extensively, with particular reference being placed on the construction process, and associated limitations, and the transportation, placement and compaction of the foamed tar stabilised material. The stockpiling ability of foamed tar and the structural capacity of the constructed test section will be evaluated. Finally conclusions will be drawn concerning the application of this technology and its success in providing an economically viable alternative for the construction of low volume roads through community involvement.