Sprayed seals are the major surfacing of the vast rural road network in Australia. They are a relatively low cost treatment compared to other forms of suitable pavement surfacing. Increases in the size and number of heavy vehicles used for freight movement are placing greater demands on pavements and sprayed seal surfacing. Forecasts indicate that this increase will continue and larger trucks are envisaged. An Austroads seal design project was started in 1992 to investigate the performance of sprayed seals and associated design procedures. This paper gives an overview of the history of seal design and the outcome of the development of an improved seal design method that highlights the various factors that need to be taken into consideration (but are often overlooked) by designers as part of the overall design procedure. The design covers the influence of aggregate shape and in particular the effect of heavy vehicles. The design philosophy is based on the design of single/single seals, but includes separate sections for the design of various other types of treatment, using conventional and modified binders, geotextile and fibre reinforcement. (a) For the covering entry of this conference, please see ITRD abstract no. 0612AR242E.
Samenvatting