Laboratory Characterisation of Locally Available Non-standard Materials for Road Pavement Application

The majority of the Australian road network consists of unbound granular pavements with a thin bituminous surfacing. In Queensland, regional and remote areas, economic and environmental considerations encourage the use of locally available materials for the provision of granular pavements resulting in lower use of finite resources and a reduction in material transportation costs and associated emissions. These materials, known as non-standard or marginal materials, typically do not meet all the Queensland standard specification requirements but provide satisfactory performance when properly managed. At present, a universally accepted testing procedure for assessing the performance of non-standard materials is lacking. This paper reports on the first completed stages of a study aiming to investigate the physical and mechanical properties of non-standard materials using a range of laboratory testing: wheel tracking, modified Texas triaxial, California bearing ratio tests, and physical characterisation testing such as particle size distribution, Atterberg limits, compaction test, and apparent particle density measurement. This paper assessed 10 different non-standard materials together with one standard material using the selected laboratory tests. Later stages of the ongoing project, conducted for the National Asset Centre of Excellence (NACoE), will expand this testing and aims to develop a performance-based non-standard material screening tool to assist in material selection and assessments for road pavement construction and maintenance in low-traffic and low rainfall areas.