Research On The Designing Of Asphalt Mixture Based On The GTM Design Method

Gyratory Testing Machine (GTM) method designs asphalt mixture with mechanical properties index. It was proved that this designed mixture has good rutting resistance and strong adaptability to heavy traffic. GTM design method has been widely applied in Tianjin City, Hebei province and other partial and cities in China, but it is still on the primary stage in Jiangsu province. In the view of the requirements of heavy traffic, the climate and the condition of traffic in Jiangsu province, it's necenecy to find a way to design mixture which can have good rutting resistance. The design method based on the GTM test can improve the quality of alphat pavement construction and satisfy the different traffic and climate.This paper tried to confirm the mature gradation range of asphalt mixture, the test parameters and design parameters of GTM by testing. By comparing to find the high-temperature behavior evaluation methodology which suited to the GTM, and testing the pavement performance under above condition in order to support the conclusions in this paper.Firstly, chief causes of rutting in Jiangsu province and GTM test method are introduced in this paper. By analyzing the causes of rutting to find out the key factor in rutting prevention, and introducing GTM test method to master the design parameters, theorem, and principle as the base of studying of designing rutting resistance asphalt mixture with GTM method.After introduction the testing method of GTM, it needs to confirm the mature gradation range of asphalt mixture, the testing parameters and design parameters of GTM. by contrast analysis on the mature gradation range of GTM in other provinces, improved AC tape mixture gradation range in Jiangsu province and Superpave tape mixture to confirm a gradation range which well adapted to Jiangsu province; by analyzing the typical road axle load spectrum in Jiangsu province to confirm the specific ground pressure; by comparing each usage performance indexes under different initial mechanical angel to confirm the best initial mechanical angel, and the selection method of defining design parameter.Then, if all the parameters are have been confirmed. By comparing different high-temperature behavior evaluation methodologies to select two kind evaluation methods, and using them to test the high-temperature behavior of GTM mixture. Lastly, by evaluating the GTM, Marshall, and Superpave under similarity conditions to ensure the selected gradation and parameters.The result of the contrast test show:compared to the asphalt mixture which designed under the samely condition of the Marshall design method and Superpave design method, the asphalt mixture which designed under the range of asphalt mixture, the testing parameters and design parameters of GTM design method has better rutting resistance, and the resistance to low-tempreture, water and matigue have not obvious difference.