Warrego Highway Recycling (Jul 1980)

The Warrego Highway is the principal road link between Brisbane and Toowoomba, a major provincial city on the eastern edge of the Great Dividing Range some 130 km to the west. The four-lane section of the highway extending nearly 6 km east from Toowoomba to Withcott, part of which traverses the Toowoomba Range, was constructed some 20 years ago. Its use by many road transport operators in preference to coastal routes, combined with a normal growth rate of other vehicles, has increased the volume of traffic to a current level of 4000 vehicles per day. In a situation of deteriorating pavement serviceability the Main Roads Department has commenced a major pavement strengthening programme particularly in the slow, heavy-vehicle lanes. After a detailed pavement evaluation and the consideration of design alternatives the MRD selected a reconstruction method which centred on recycling the existing pavement using cement stabilisation prior to overlaying. This article outlines the evaluation procedures, the reasons for the adoption of pavement recycling and the construction methods used.