DefinePK

Abstract

Many researches used dissipated energy approach to find the changing of the asphalt binder properties through repeated cyclic loading with accumulation of damage. In this research time-sweep and stress - sweep tests were used to simulate fatigue phenomenon for the different production refineries of Iraqi asphalt binders (Nasiriya, Daurah and Basrah) by applying repeated cyclic load of strain or stress at chosen loading frequency and temperatures. The asphalt binders were aged by rolling thin film oven for simulating influence of oxidation in the mixing and compaction of HMA, and pressure aging vessel to represent long term oxidation life. All the tests were conducted at 10 Hz at intermediate temperatures and 3 percent of strain that closest to the HMA mixture beam fatigue behavior [1], different mathematical models were founded to represent relation of the dissipated energy ratio and fatigue life at constant stress value (150 and 200) kPa for RTFO aging and 300, 350 kPa for PAV aging. It was found that fatigue life of Al-Nasiriya asphalt binder more than Daurah and Basrah by 67%, 187% respectively for long term aging. In general, it was noticed that the stiffness modulus (G*) values accelerated and quickly reached to the failure criteria, as decreased about 55% of the original G* value.