Selection of proper mode for pavement rehabilitation – a challenge for engineers

The Government of Sri Lanka is investing heavily on infrastructure development which is the gateway to the economic development of the country. Accordingly, a significant number of national, provincial and rural road projects have been implemented. Designs for most of these road projects are done according to the international standards. There are a number of techniques available to rehabilitate or upgrade pavements and the intended benefits cannot be reaped unless a judicious technique is followed. This paper covers an example of an estimating design equivalent standard axles and a comparison of two common surfacing techniques, viz., thin bituminous surfacing and thin asphalt surfacing. Pavement structure is analysed using mechanistic method. The significance of mechanistic method over empirical approach is highlighted. The fallacy of the belief that the design life of pavement increases monotonically with the thickness of asphalt layer is revealed. The analysis leads to the selection of suitable pavement structure