Using discrete element models to track movement of coarse aggregates during compaction of asphalt mixture

Abstract The objective of this study is to analyze the movement characteristic of differently-shaped compositions in the Superpave Gyratory Compactor (SGC) test through tracking coarse aggregates and the numerical simulation of Discrete Element Method (DEM). First, the coarse aggregates were classified into five shape types (rounded, fractured, angular, elongated and flat) and scanned by a 3D scanner. Second, seven groups of asphalt mixtures with different combination types of hybrid, 100%fractured, 100%angular, 80%fractured + 20%rounded, 60%fractured + 40%rounded, 80%fractured + 20%elongated, and 80%fractured + 20%flat groups were simulated by Particle Flow Code (PFC) Version 5. Third, numerical simulations were conducted to analyze the SGC test process and the movement paths of differently-shaped coarse aggregates were obtained. Finally, statistical analysis on the results from the modeling test were used to study the movement characteristics of asphalt mixtures with differently-shaped aggregate compositions. Through this study, it was found that: (1) there were three main stages of particle movement in the SGC test; (2) the ratio of vertical displacement was obviously larger than that of horizontal displacement, while the variation of vertical rotation was obviously smaller than that of horizontal rotation in asphalt mixtures with differently-shaped compositions; (3) the rounded, elongated and flat coarse aggregates have greater influence on horizontal displacement compared with vertical displacement, but have adverse effects on particle rotations during the compaction process; (4) the effects of elongated coarse aggregates on particle movement were larger than those of flat coarse aggregates, but the flat coarse aggregates have more influence on particle rotation for the variations of horizontal and vertical rotational angles.

[1]  Hainian Wang,et al.  Aggregate Morphological Characterization with 3D Optical Scanner versus X-Ray Computed Tomography , 2018 .

[2]  William G. Buttlar,et al.  Discrete Element Modeling of Asphalt Concrete: Microfabric Approach , 2001 .

[3]  R. Miró,et al.  Effect of compaction temperature and procedure on the design of asphalt mixtures using Marshall and gyratory compactors , 2014 .

[4]  Glenn R. McDowell,et al.  Discrete element visco-elastic modelling of a realistic graded asphalt mixture , 2014 .

[5]  T. W. Kennedy,et al.  VOLUMETRIC AND MECHANICAL PERFORMANCE PROPERTIES OF SUPERPAVE MIXTURES , 2000 .

[6]  Yongli Zhao,et al.  Study of movement of coarse aggregates in the formation process of asphalt mixture in the laboratory , 2016 .

[7]  Jingsong Chen,et al.  DEM Simulation of Laboratory Compaction of Asphalt Mixtures Using an Open Source Code , 2015 .

[8]  Yu Liu,et al.  A New Method for Characterizing Coarse Aggregate Morphology through a MATLAB Program , 2016 .

[9]  K. Pye,et al.  Particle shape: a review and new methods of characterization and classification , 2007 .

[10]  Yu Liu,et al.  Three-dimensional discrete element modeling of asphalt concrete: Size effects of elements , 2012 .

[11]  P. Léger,et al.  Earthquake Safety Evaluation of Gravity Dams Considering Aftershocks and Reduced Drainage Efficiency , 2008 .

[13]  S. Y. Wong,et al.  Quantification of movements of flat and elongated particles in hot mix asphalt subject to wheel load test , 2005 .

[14]  Sanjeev Adhikari,et al.  Dynamic modulus simulation of the asphalt concrete using the X-ray computed tomography images , 2009 .

[15]  Zhanping You,et al.  Discrete-Element Modeling: Impacts of Aggregate Sphericity, Orientation, and Angularity on Creep Stiffness of Idealized Asphalt Mixtures , 2011 .

[16]  Hussain U Bahia,et al.  Effect of Fine Aggregate Angularity on Compaction and Shearing Resistance of Asphalt Mixtures , 2002 .

[17]  Zhanping You,et al.  Visualization and Simulation of Asphalt Concrete with Randomly Generated Three-Dimensional Models , 2009 .

[18]  Feng Chen,et al.  Application of discrete element method to Superpave gyratory compaction , 2012 .

[19]  Jian-Shiuh Chen,et al.  Quantification of Coarse Aggregate Shape and Its Effect on Engineering Properties of Hot-Mix Asphalt Mixtures , 2001 .

[20]  Xiang Shu,et al.  Air-Void Distribution Analysis of Asphalt Mixture Using Discrete Element Method , 2013 .

[21]  H. Bahia,et al.  Effects of Temperature and Pressure on Hot Mixed Asphalt Compaction: Field and Laboratory Study , 2008 .

[22]  Erol Tutumluer,et al.  Evaluation of image analysis techniques for quantifying aggregate shape characteristics , 2007 .

[23]  Zhanping You,et al.  Compaction characteristics of asphalt mixture with different gradation type through Superpave Gyratory Compaction and X-Ray CT Scanning , 2016 .

[24]  Yongli Zhao,et al.  Investigation of the shape, size, angularity and surface texture properties of coarse aggregates , 2012 .

[25]  J. R. Fernlund,et al.  Image analysis method for determining 3-D shape of coarse aggregate , 2005 .

[26]  Hai Huang,et al.  Characterization of particle movement in Superpave gyratory compactor at meso-scale using SmartRock sensors , 2018, Construction and Building Materials.

[27]  Yu Liu,et al.  Discrete element modeling of realistic particle shapes in stone-based mixtures through MATLAB-based imaging process , 2017 .

[28]  Samuel H Carpenter,et al.  Effect of Flat and Elongated Coarse Aggregate on Field Compaction of Hot-Mix Asphalt , 2001 .

[29]  Yu Liu,et al.  Viscoelastic Model for Discrete Element Simulation of Asphalt Mixtures , 2009 .

[30]  Zhanping You,et al.  Lab assessment and discrete element modeling of asphalt mixture during compaction with elongated and flat coarse aggregates , 2018, Construction and Building Materials.

[31]  Ala R. Abbas,et al.  Micromechanical Modeling of the Viscoelastic Behavior of Asphalt Mixtures Using the Discrete-Element Method , 2007 .