نوع مقاله : یادداشت فنی
نویسندگان
دانشکده عمران، دانشگاه علم و صنعت ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Permanent deformation is an important factor in flexible pavement design. Through increasing traffic load and tire pressure most permanent deformation occurs in the upper layer rather than in subgrade.Wheel tracking is a popular HMA test, since it simulates the permanent deformation resistance of mixtures. The basic similarity of these devices is in using a cyclic wheel passing through the surface of specimens, and the cumulative rut after the proposed cycles is used as a measure of rutting potential. The wheel tracking test is undertaken using the Iran University of Science and Technology, ABRC Wheel Track machine, by applying 8000 cycles of wheel load of 50kg that turns around an axis and applies the wheel load to specimens. The test was done at $60^{\circ}C$.In this study, the rutting performance of hot mix asphalt specimens made with bentonite as bitumen modifiers were studied. 10\%, 15\%, 20\%, 25\% and 30\% bentonite content by weight of asphalt cement were used as its modifier. A propeller mixer was used for blending the bentonite and asphalt cement. In this study, the rutting performance of modified asphalt mixtures was evaluated through various laboratory tests, such as Marshall stability and permanent deformation The test methods used in this evaluation were the dynamic creep test and wheel tracking tests. The results demonstrated that the use of bentonite can enhance Marshall stability and resistance to permanent deformation of mixtures. The mixtures also show good resistance to permanent deformation, evaluated by means of wheel tracking tests.
کلیدواژهها [English]
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