Research On Fatigue Properties Of Reclaimed Asphalt Mixture From Central Plant

In China, road has been turning from construction period to curing period after decades of leap-forward development. Moreover, so much waste asphalt mixture has been produced in construction, repair and maintenance. Of course, it will cause serious pollution to the environment if mishandled. Therefore, in order to save material, resource and cost, and also protect the environment, many areas in the world are turning to the recycling of such waste asphalt mixture in road construction and maintenance. However, reclaimed asphalt pavement(RAP) appears fatigue rupture easily because the reclaimed asphalt mixture(RAM) is so complex and influenced by such factors as climate and traffic. This paper analyzed the indirect tensile fatigue characteristics of the hot RAM made from the waste asphalt mixture recycled from Nanjing-Airport Expressway. The results of this paper will provide a reference for future use of regeneration asphalt pavement.In this paper, the content of old asphalt, the performance index and the old aggregate grading were measured based on the performance of waste asphalt mixture, also the performances of new asphalt, aggregate and regenerate were assessed through tests. It’s showed that the performance of all the materials used met the specification requirements. Then, the aggregate grading of RAM was designed with Marshall Design Method. The percentages of 0%, 10%, 20%, 30%, 40% and 50% of RAP were separately added into AC-20 C respectively. The performances of those RAM were measured and compared through tests. The results showed that all the RAM had good high temperature stability, water stability and low temperature crack resistance.Indirect tensile fatigue test was determined to be used here by comparing the advantages and disadvantages of many fatigue tests and considering the actual study. The impacts of factors such as RAP mass fraction, stress ratio, loading frequency, temperature, regenerate and degree of aging on the tensile fatigue characteristic of RAM were analyzed. Meanwhile, the stress ratio-logarithmic fatigue life equations were established for different test conditions.