Discrete-Element Modeling: Impacts of Aggregate Sphericity, Orientation, and Angularity on Creep Stiffness of Idealized Asphalt Mixtures

Liu, Yu; You, Zhanping

doi:10.1061/(asce)em.1943-7889.0000228

Cited by 72 publications

(30 citation statements)

References 27 publications

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“…According to a study by Craus et al (1978), the AAI is caused due to the complex physico-chemical processes and is related to various factors, including acid-base property and surface characteristics of aggregates, and the components and properties of asphalt binder. The properties of aggregates can significantly affect the AAI, and the alkaline aggregate, the bigger specific surface area, higher surface energy and more rough surface texture of aggregate are beneficial to AAI (Chen and Tan 2007, You and Dai 2007a, 2007b, Liu and You 2011.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of asphalt–aggregate interaction based on the rheological properties

Zhang

Fan

et al. 2016

International Journal of Pavement Engineering

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The silicon dioxide (SiO 2 ) and calcium oxide (CaO) analytical reagents are selected to prepare asphalt mastics and the effects of aggregate chemical composition on asphalt-aggregate interactions (AAI) are evaluated based on the complex modulus and phase angle. It is found that the oxide analytical reagents significantly affect the rheological properties such as complex shear modulus and phase angle, and the effects of CaO are greater than SiO 2 due to the stronger interaction between asphalt binder and CaO analytical reagents. Both the modulus stiffening ratio and the phase angle-based K. Ziegel-B coefficient could be used to evaluate the AAI, and the latter is the better index. Results show that the indexes increase with the test temperature, but decrease with the loading frequency, and tend to be constant. The higher adhesive strength between asphalt binder and limestone than basalt is likely attributed to the higher content of CaO in limestone aggregate and the stronger asphalt-CaO interaction.

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Section: Introductionmentioning

confidence: 99%

Evaluation of asphalt–aggregate interaction based on the rheological properties

Zhang

Fan

et al. 2016

International Journal of Pavement Engineering

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“…The discrete element method (DEM) is an efficient computational method for predicting the structural and mechanical characteristics of the asphalt mixtures (You and Buttlar 2004). Over the past two decades, the DEM has been widely applied to analysis of the interface contact behavior between aggregates in the mixtures (Liu et al 2011;Dan et al 2018).…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Simulation of Aggregate and Asphalt Mixture Using Parameterized Shape and Size Gradation

Zhang

Qian

et al. 2019

J. Mater. Civ. Eng.

129

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Aggregate occupies at least three-quarters of the volume of asphalt mixture and can significantly affect the performance of pavement. The geometrical morphology influences the slippage and interlock among aggregates for resisting and distributing applied loads. In recent years, the discrete element method (DEM) has been employed for simulation of asphalt mixture structure. This paper introduces an approach for simulation of aggregate and asphalt mixture using parameterized shape and size gradation. Both plane geometry factor (PGF) and section aspect ratio (SAR) were employed to describe the 3D geometric characteristics of aggregates. A numerical technique of aggregate models was implemented with probabilistic parameters depending on statistical results of PGFs and SARs. Therefore, the 3D numerical model of asphalt mixtures was assembled with three different components, which is validated by uniaxial compression test via comparison with that of the laboratory result. It was found that the PGF and SAR are appropriate to describe the three-dimensional features of aggregate shapes, due to the fact that a simplified space object can be described by a 2D graphical projection and a vector scalar corresponding to the space vector. Probability distribution curves of PGFs and SARs between coarse aggregates are in concordance with the Gauss-type function, since their correlation coefficients are all greater than 95%. It was verified that the developed clumping algorithm of aggregates was reasonable with the shapes and size gradation. Based on the parallel-bond model and the Burger's model, the results of virtual tests are in good agreement with those of laboratory uniaxial tests. It is shown that the angularity (PGF) of aggregates has a beneficial effect on the strength and stability while the flat-elongated feature (SAR) has a negative effect on those of asphalt mixtures.

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“…Afterwards, Qian et al [14] and Yang et al [15] adopted the cohesive models to reflex the viscosity characteristics of asphalt mastics. Meanwhile, a mesoscopic Burgers viscoelastic contact model (embedded by "Itasca Corporation") instead of the simple bond contact models was applied in analyzing the viscoelastic mechanical response of asphalt concrete [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. Research showed that mesoscopic viscoelastic contact models influenced the asphalt concrete performance significantly, especially the rheological behavior.…”

Section: Introductionmentioning

confidence: 99%

Influence of the Mesoscopic Viscoelastic Contact Model on Characterizing the Rheological Behavior of Asphalt Concrete in the DEM Simulation

Ren

Liu

Xue

et al. 2020

Advances in Civil Engineering

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The numerical simulation based on the discrete element method (DEM) is popular to analyze the material behavior of asphalt concrete in recent years because of the advantage of the DEM in characterizing the heterogeneous microstructures. As a type of viscoelastic material, the rheological behavior of asphalt concrete is represented depending on the mesoscopic viscoelastic contact model between two particles in a contact in DEM simulations. However, what is missing in the existing literature studies is analysis of the influence of the mesoscopic viscoelastic contact models. Hence, the existing mesoscopic viscoelastic contact models are employed to build different types of DEM numerical samples of asphalt concrete in this study. Laboratory tests and the corresponding numerical tests at different temperatures and frequencies are implemented to investigate the difference in simulation precision in the case of using different mesoscopic viscoelastic contact models via the rheological index of dynamic modulus and phase angle. The results show the following: (1) the mesoscopic generalized Maxwell contact model provides the best simulation precision at low temperatures; (2) the mesoscopic generalized Kelvin contact model shows an improved precision at high temperatures; and (3) although the mesoscopic Burgers contact model has the simplest mathematical structure, the simulation precisions are obviously lower than those of the other two contact models, particularly when simulating the phase angle at low temperatures and frequencies. The results will be beneficial to select the appropriate mesoscopic contact model for the DEM modeling of asphalt concrete according to the loading conditions.

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Discrete-Element Modeling: Impacts of Aggregate Sphericity, Orientation, and Angularity on Creep Stiffness of Idealized Asphalt Mixtures

Cited by 72 publications

References 27 publications

Evaluation of asphalt–aggregate interaction based on the rheological properties

Evaluation of asphalt–aggregate interaction based on the rheological properties

Three-Dimensional Simulation of Aggregate and Asphalt Mixture Using Parameterized Shape and Size Gradation

Influence of the Mesoscopic Viscoelastic Contact Model on Characterizing the Rheological Behavior of Asphalt Concrete in the DEM Simulation

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