Pavement

The majority of sprayed seal design methods around the world are based on the work of Hanson, published in 1935. However, there are growing weaknesses in current sprayed seal design models. Traffic loads have increased, particularly in both the number of heavy vehicles, and the loads that individual prime movers are now hauling.

In September 2008 a test pavement consisting of unbound granular basecourse with a double/double sprayed seal was constructed at the current Accelerated Loading Facility (ALF) site in Dandenong South, Melbourne. This pavement is being repetitively loaded with varying combinations of single axle, tandem axle and triaxle loading cycles, whilst surface texture measurements are being recorded.

Analysis of the surface texture reduction supports the hypothesis that axles of the same loadings but in clustered groupings cause a significantly different reduction in surface texture than in smaller groupings. The analysis also supports the hypothesis that the pavement design concept of equivalent standard axles is not applicable to sprayed seal design.