Prediction of asphalt pavement temperatures in South Africa

Abstract

Paper presented at the 20th Annual South African Transport Conference 16 - 20 July 2001 "Meeting the transport challenges in Southern Africa", CSIR International Convention Centre, Pretoria, South Africa.The subject of temperature variations in pavement layers has been studied at various times in the past, but recently with the advent of the SHRP Superpave project become of vital importance. Superpave programmes characterise the required binder properties in terms of expected pavement temperatures, and hence the ability to predict temperature extremes at any depth in an asphalt pavement at a proposed construction site is vital. Similarly the current testing of pavements with the Falling Weight Deflectometer (FWD), which is used in rehabilitation design, also requires accurate predictions of real time asphalt temperature at defined depths in order to understand the nature of the moduli determined. This report utilizes data collected during a project funded by the South African National Roads Agency, and undertaken by Bradford and Conning, Civil Engineers and the Civil Engineering Programme, University of Natal, Durban, as well as some subsequent temperature monitoring. The later monitoring was carried out under supervision, by students R F Ngcobo (1999) and O J Maimane (2000), as part of an undergraduate research programme at the University.