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چكيده انگليسي :

The Investigation into the Mechanical Behavior of Asphalt Mixture using Finite Element Method Vahid Ziaei Rad v ziaeirad@cv iut ac ir Date of Submission 2011 09 18 Departmentof Civil Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Seyed Mahdi Abtahi mabtahi@cv iut ac ir BehroozKoosha cgkoosha@cv iut ac irAbstractNowadays in scientific conference utilizing finite element method to investigate pavement mechanical responses indifferent conditions has taken much into consideration with respect to latest high performance computers Suchmethod can consider geometrical properties materials behavior state of loading and boundary conditions with ahigh accuracy very close to the real condition Simulation of asphalt mixture in micro scale such that it would bepossible to consider each of mixture components separately leads to get a more accurate viewpoint in the field offlexible pavement performance Therefore by calculating the magnitudes of stress strain and displacement in anyarbitrary location in asphalt mixture prediction of local and large scale distress will be more probable Moreover understanding better the performance of asphalt mixture components and calculating more accurate pavementresponses can direct to a more appropriate mixture design with high performance and long life Thus mechanicalsimulation of asphalt mixtures is considerable Although the subject is important up to now there are limited studies in the field of micro structural simulation ofasphalt mixture Simulating the complex geometrical structure and materials behavior of asphalt mixtures is in thefirst steps and it seems that the obtained results in previous studies are not reliable independent of tests andexperimental investigations Therefore it seems essential to conduct more investigations in the mentioned field In this study with the aim of finite element method the geometrical structure and components behavior of sometypes of asphalt mixtures are simulated Especially a novel method is expressed which can consider the complexgeometry and gradation of asphalt mixture This especial method of geometrical simulation is formed with theusefulness of some molecular dynamic concepts and by the aim of writing Python scripts in ABAQUS software Theeffect of various types of aggregate gradation on asphalt layer responses is investigated Therefore different types ofasphalt mixtures consisting of asphalt concrete porous asphalt stone matrix asphalt and large stone porous mixtureare geometrically simulated and their responses are evaluated under different loading and boundary conditions withthe consideration of mastic component visco elastic behavior in two different temperatures The effect of vehicleloading speed type of wheel free or driven and also soil layers on the horizontal and vertical displacement ofasphalt layer surface are investigated Moreover crucial regions in asphalt mixtures are determined for the masticand the state of stress in such regions is evaluated In addition with respect to mechanical responses of asphaltmixture the fatigue life of the asphalt layer and probable types of distress are somehow predicted The magnitudesrelated to different mechanical responses for all mentioned types of asphalt mixture in different conditions aredemonstrated in various figures and tables Keywords Asphalt mixture finite element method micro structural simulation geometrical structure pavementresponse

ضيائي راد، وحيد

بررسي رفتار مكانيكي مخلوط هاي آسفالتي با روش اجزاي محدود

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