This paper describes the results of the analysis of the data collected during accelerated loading trials of unstabilised sandstone bases, and sandstone bases stabilised in situ with 2 percent bitumen and 2 percent cement, conducted with the Accelerated Loading Facility (ALF). It was found that the life of the typical pavement with a nominal 125 mm of unstabilised sandstone could exceed the maximum design life of 106 ESAs expected for this pavement type under dry conditions. However, the pavement was very sensitive to loads and had a load damage exponent of 6 to 8 as compared to a value of 4 (i.e., the fourth power law) for other pavement types. Comparison of the performance of six reconstructed sandstone pavements suggested that the effects of pavement thickness and sandstone quality were not significant under low axle loads, but may be significant under higher axle loads. Comparison of the performance of 2 percent bitumen and 2 percent cement-stabilised and unstabilised pavements suggested that the stabilised sandstone layer had a higher stiffness and produced a lower deformation than the unstabilised sandstone. The stabilised material was also more resistant to moisture penetration. (A)
Samenvatting