ASSESSMENT OF RESISTANCE TO RUTTING OF ASPHALTIC MATERIAL USING A WHEEL TRACKER

Asphalt pavement rutting is one of the most common pavement distresses, observed in Pakistan as a consequence of increased tire pressures, slow moving heavy loads and high temperature. Maintenance and rehabilitation costs of flexible pavements are alarmingly high. A laboratory based evaluation of resistance to rutting of six mixes using three asphalt cement types i.e. Polymer modified Asphalt, 60/70 and 40/50 penetration grade was conducted at standard wheel loading of 700+20 Newton on wheel tracker and varying temperature levels i.e. 25, 40, 55oC. Relationships between rutting and factors effecting rutting have beenestablished and ranking of mixes based on regression coefficients were performed. It was revealed from the current study that mixes with coarser gradation and polymer modified asphalt showed better resistance against rutting and obtained a better ranking. Linear trends have been observed between the increase in temperature and rut value