Using Compaction Parameters And Indirect Tensile Strength To Evaluate Asphalt Concrete Rutting Potential

With the increasing of the traffic, automobile axle loads and the channelized traffic forming, so the problems, which come out of over loaded and heavy loaded car are more and more outstanding, the rutting damage in asphalt surface of highway in our country has already become a noticeable problem.Rutting in asphalt concrete can occur from two types of mechanical response: viscous flow and plastic deformation. Plastic deformation occurs as aggregate particles move slightly relative to one another, which is accompanied by viscous flow in the asphalt cement binding these particles together.The behavior of asphalt concrete can be analyzed by the Mohr-Coulomb failure theory. This theory predicts that the strength of a material such as asphalt concrete depends upon both cohesion and internal friction. The internal friction is an important parameter, indicating the degree of interaction among particles. An asphalt mixture made of aggregates with relatively poor internal friction is more susceptible to rutting. The cohesion, in asphalt concrete, is a parameter that indicates how strongly the binder can bind the aggregates together. It is mostly a function of binder content, binder grade and mix temperature.The IDT strength test is a measure of tensile strength and a good indicator of mixture cohesion. IDT strength would provide information on cohesion, specifically asphalt binder stiffness, but not angle of internal friction provided by the aggregates. The compaction parameters, which is derived from SGC, captured changes in aggregate characteristics, but was insensitive to asphalt binder volume and stiffness.So it could be expected that compaction parameters would provide information on the angle of internal friction, ?, but not on cohesion, c. Thus the use of compaction parameters, along with IDT strength can provide an indicator of rutting resistance of an asphalt mixture.The objective of this paper is to verify if the rutting resistance of an asphalt mixture, as determined from the asphalt pavement analyzer (APA), is a function of the compaction parameters as derived from the SGC, volumetric properties and the IDT strength of the mix, as evaluated from Marshall Stabilometer.