Laboratory Characterisation Of Non-Standard Pavement Base Materials

The vast majority of the road network in Australia is composed of unbound granular pavement layers. Given the annual growth in the use of granular materials in the construction and maintenance of pavements, there is a significant increase in energy and materials’ transportation cost and remarkable shortages/reduction of conventional quality materials. Therefore, there is an overriding need to employ locally available non-standard materials as a sustainable solution for pavement construction and maintenance which will result in reduced consumption of finite resources and a reduction in cost. Although non-standard materials do not generally meet the requirements of standard specification, they can result in a satisfactory performance when properly managed. Currently, there is no unified accepted test method to evaluate the performance of non-standard materials. The objective of this paper is to have a comprehensive evaluation of the physical and mechanical properties of non-standard materials using a range of laboratory experiments. For this purpose, seven non-standard materials sampled from the existing pavements together with one standard material were selected for the laboratory investigation. The adopted laboratory experiments included California Bearing Ratio (CBR), modified Texas triaxial, and wheel tracking tests in addition to the compaction test, particle size distribution, Atterberg limits measurements, and apparent particle density measurement. This study ranked and compared the performance of different tested materials under selected laboratory experiments. Lastly, the laboratory test results were compared against the materials’ in-service performance and the suitability of each adopted experiment for the characterisation of non-standard materials was accordingly investigated.