Question vi: roads in developing areas, Australia

In an era when the demand for funds for the construction and maintenance of roads generally exceeds available funds, it is increasingly important that works are carried out in the most cost effective manner. This is particularly important in Australia where long road distances separate the main centres of population. The accelerated loading facility is providing valuable information on the design and performance of pavements. The development and introduction of pavement management systems promises to provide a powerful tool for the prediction of pavement conditions and the determination of optimum strategies for the management of pavements within available funds. The control of vehicle loading is necessary for both the reduction of damage to road pavements and road safety reasons. Two new systems combining portability, accuracy and relatively low cost for the measurement of vehicle weights are described. A number of developments in bitumen seal technology are presented. Modified bitumen binders are being used increasingly to reduce the effects of cracking in seals and to resist the increased forces from traffic on seals at such places as sharp bends. Two separate programmes testing the effectiveness of hydrated lime and lead diamyldithiocarbamate in reducing the hardening of bitumen caused by the attack of atmospheric oxygen are being carried out. Experience with the effects on bitumen of extreme concentrations of soluble salts in construction water and pavement materials is described. For economic reasons it is often necessary to use pavement materials that fall short of normally accepted standards. There are many instances where marginal materials have been used in a wide range of situations. A coarse selection process for materials is presented. Remote sensing techniques are being developed which use satellite data and aircraft mounted radar to provide information on rock and soil types, vegetation and drainage patterns. The techniques are seen as being particularly useful in remote areas where mapping of any type may be of poor quality or non existent (a).