Bitumen rubber asphalt mix testing for South African pavement design method

Abstract

The South Africa National Road Agency Ltd has entered into a research and laboratory testing agreement with the CSIR to support the revision of the South African Pavement Design Method (SAPDM). The research includes characterising a bitumen-rubber semiopen graded mix, known in South Africa as BRASO. The general concern was whether the BRASO asphalt mix can be tested under the same test conditions as conventional asphalt mixes using the recently developed test protocols for SAPDM. This paper presents the analyses of laboratory testing data of a BRASO mix. The fundamental mechanical properties, including dynamic modulus, permanent deformation and beam fatigue characteristics of the BRASO, were determined in laboratory to enable future monitoring of the field performance of BRASO. It is anticipated that the test results presented in this paper will provide the required basis to develop reliable BRASO resilient response and damage models for SAPDM.