Analytical investigation on the influence of loading and temperature on top-down cracking in bituminous layers

Existing flexible pavement design methods consider permanent deformation and cracking of bound layers as the main failures to be precluded or controlled. Cracking of bound layers can be due to low temperature or fatigue failure due to repeated load applications. Fatigue failures caused by repeated flexure of the bituminous bound layers usually start with the initiation of crack at the bottom of the bituminous layer and propagates upwards (bottom-up cracking). But in the recent past, premature failures of top down cracking (TDC) have been reported across the world including some stretches of the Indian national highways. Thus to have a design method for bituminous mixes and pavements that ensures satisfactory long-term performance under a wide range of loading and climatic conditions, understanding the response of pavements to various factors that are believed to cause TDC is necessary. The present paper investigates the effect of high temperature and overloading on cracking potential in bituminous layers using elastic layer theory.