RECENT ADVANCES IN PERFORMANCE BASED CHARACTERISATION OF ASPHALT MIXTURES – A REVIEW

This paper reviews recent advances in performance based characterisation of asphalt mixes. A number of factors have necessitated the requirement for performance based tests on asphalt mixes. The need to design long lasting asphalt pavements in order to preserve resources and keep capital expenditure to a minimum is a major factor.In the past, empirical properties derived from previous experience were generally used to predict the service performance of asphalt mixes. Performance based tests however, provide engineering properties of asphalt mixes. These properties can be used to predict the service performance of the mixes.Performance based characterisation of asphalt mixes is therefore one of the most crucial steps in designing long lasting asphalt pavements. Characteristics such as rutting potential, fatigue and thermal cracking behaviours can be analysed through performance based tests. Since the implementation of Superpave in 1993, numerous tests such as wheel tracking and indirect tensile test have been used to investigate the fundamental properties of asphalt mixes. However, recent analysis of some of these tests have shown their limitations, the most common being that laboratory test data are at variance with field test data.As a result, modifications to previous test methods and completely new test methods are being researched and introduced in order to overcome the limitations of existing ones. The aim of this paper is to provide brief discussions on these limitations (showing the necessity of developing new robust methods) as well as discussions on some of these new test methods.

Keywords:

Fatigue , Thermal cracking , Dynamic modulus