Evaluation of Crack Potency in the Bituminous Concrete using Fracture Mechanics Parameters

Fatigue cracking is very critical among all types of distresses in pavements once the fatigue crack start in pavement it led to fast pavement deterioration and thus reduced the life of pavement and quality of riding on pavement. Thus, to control such distress it is necessary to understand the mechanics behind such crack initiation and propagation and to find the fracture parameters to choose best mixture to resist the failure. There are various methods to understand the fracture properties of the bituminous concrete (BC) mix. This paper describes the semi-circular bending test for BC mix, which was designed to be very effective, and user friendly. This method is adopted because it simulates the field conditions and its availability. Semi-circular samples of forty-eight were prepared out of which half was made of unmodified bitumen and the rest were made of plastic modified bitumen. These all samples were then tested at different loading rates and value of load at each deflection is measured. Two fracture parameters like fracture energy and stress intensity factor are evaluated. The plastic modified bituminous concrete shows that the value of energy is increased 2 to 3 times than the unmodified bituminous concrete at intermediate temperature. Hence, plastic modified bituminous concrete has the greater cracking resistance potential.