Road stabilisation issues in southern district of the Department of Main Roads, Queensland

Abstract

Queensland has a public road network of 175, 000Km that is made up of both flexible and rigid pavement types. These pavements are usually designed for a life expectancy of approximately 20 years; however, the presence of poor subgrades can influence both the durability and life of these pavements. Investigations of lime stabilised black soil in Dalby, Queensland were carried out to determine the effects of delayed testing and to determine if Hilf Density Testing is a viable method for inclusion in future Queensland Main Roads specifications. Both Dry Density Testing and Hilf Density Testing were carried out over a 48 hour period. In addition to density testing investigations, the main aim of the project was to find whether there was a strength gain relationship for lime stabilised black soils.