Construction of a high modulas aspalt (HiMA) trial section Ethekwini: South Africa's first practical experience with design, manufacturing and paving of HIMA

Abstract

Paper presented at the 31st Annual Southern African Transport Conference 9-12 July 2012 "Getting Southern Africa to Work", CSIR International Convention Centre, Pretoria, South Africa.

A trial section was paved with the recently introduced High Modulus Asphalt (HiMA) technology on South Coast road in eThekwini (Durban). The trial section forms part of an effort to transfer HiMA technology to South Africa, in an initiative aimed at increasing the options available for the design of heavily trafficked pavements. Apart from rehabilitation of the road, the aim of the project was to monitor the performance of the innovative pavement material. The project is the first full implementation of the technology and follows the development of the preliminary mix design and structural guidelines for HiMA. A pavement structure including a HiMA base layer was designed for the rehabilitation of the section of the South Coast road, which had experienced severe rutting due to high volumes of trucks accessing the Durban harbour. The trial section comprises approximately 300 m of the north bound lanes, towards the intersection with Bayhead road. Approximately 190 mm of the existing pavement structure was milled out and replaced by two 80 mm HiMA as base layers, and 30 mm Stone Mastic Asphalt (SMA) as surfacing layer. The objective of this paper is to present the process that was followed in the first design and construction of a HiMA pavement in South Africa and the observations made during the construction process. Various challenges that were and lessons learned during the project are presented. The completed section shows that HiMA can be successfully designed, manufactured, and paved in South Africa.