Since 1995, Main Roads' Border (Warwick) District has been working with Road Systems & Engineering and other world leaders to trial and develop cost-effective methods of rehabilitating its aging road network. After extensive work with lime stabilisation, and two relatively small trials using foamed bitumen stabilisation, Border District has recently completed the largest foamed bitumen stabilisation job ever carried out in the Southern Hemisphere. Rehabilitation using foamed bitumen has proved to be successful because of its ease and speed of construction, its compatibility with a wide range of aggregate types and its relative immunity to the effects of weather. There are now well developed procedures for the design of foamed bitumen stabilisation which should be followed. This paper addresses: (1) the basics of foamed bitumen stabilisation; (2) situations where foamed bitumen stabilisation could be considered; (3) the design method used by the Queensland Department of Main Roads; (4) lessons learnt from the $2.5 million, 17.6 km New England Highway project; (5) what to look for when carrying out foamed bitumen stabilisation; and (6) the future of foamed bitumen stabilisation within the Queensland Department of Main Roads. Foamed bitumen has the potential to be used throughout Queensland and provides another useful tool for the rehabilitation of heavily trafficked thin high plasticity pavements. (a)
Samenvatting