PREDICTION AND IMPLICATION OF WATER REGIMES IN GRANULAR BASES AND SUB-BASES

Many pavements incorporate open-graded drainage layers in their foundations, while others have base or sub-base layers that are intended to allow water to leave the pavement structure. The drainage capacity of pavements incorporating such layers is viewed using drainage models and large-scale horizontal permeability test data. The best-estimate of likely performance is assessed and compared with in-situ evidence The implication of the deduced hydraulic regime for pavement performance (both mechanical and environmental) is then discussed. The mechanical assessment uses mechanistic pavement analysis methods in which the aggregate and subgrade stiffness is allowed to respond to the moisture regime predicted from the drainage study. The environmental assessment draws on leachability studies on secondary (recycled and waste) materials. For the covering abstract see ITRD E108441.