Western Australia (WA) is the largest in area of the Australian States and Territories and it occupies about a third of the mainland island/continent. A large proportion of WA is arid or semi-arid with a very low average population density. The majority of the population is located along the coast, around inland mineral resources and in the south west and far north in areas of agricultural production. The large geographical spread, variable near surface geology and the predominantly low rainfall environment has created both opportunity and challenge for builders of roads and airports. The challenge has been to build pavements at a low unit cost so that it is economically feasible to connect towns that are far apart. The low rainfall environment, in combination with favourable geology, has enabled local aggregates and fill materials to be used for pavement construction that would be shunned in many other places.
In this themed edition of the Australian Geomechanics Journal we have looked at several aspects of pavements in Western Australia. We have a paper looking at pavements in the early years of the Swan River colony in the mid-nineteenth century. At the other end of the time scale, we have a paper covering the introduction of warm-mix asphalt and concrete pavements on highways in WA over the last 10 years. The last decade has also seen rapid growth in the number of aerodrome pavements to serve the fly-in fly-out workforce at iron ore and oil and gas industries. Filling in the middle, we have papers on Western Australian practice in the use of natural gravel for pavement construction and local practice in the use of sprayed seal surfacing and asphalt.
The preparation of this themed edition was driven by the West Australian Pavements Group (WAPG), and supported by the WA Chapter of the AGS. This group operates as a subcommittee of Australian Geomechanics Society in WA with membership drawn from Main Roads WA, Consulting Engineers, Contractors, Local Government, ARRB and Universities. It provides a forum where opinions can be freely aired outside the constraints of tender and contracting process. The group was established in 2008 with an exchange of letters between the Chair of the WA chapter of AGS and the Commissioner of Main Roads. The WAPG meets four times a year to share the results of research and for working groups to report on areas that they have been investigating.