A Micromechanical framework with aggregate-mastic interface effect for predicting uniaxial compression creep of asphalt mixture

2014 ◽  
Vol 27 (3) ◽  
pp. 306-314 ◽  
Author(s):  
Jun Wu ◽  
Xinhua Yang ◽  
Fan Bai
Keyword(s):  
Uniaxial Compression ◽  
Asphalt Mixture ◽  
Interface Effect ◽  
Compression Creep

scholarly journals Study on Creep Behavior Of Asphalt Mixture Based on Discrete Element Method

2020 ◽  
Vol 15 (4) ◽  
pp. 174-195
Author(s):  
Youlin Ye ◽  
Yazhen Sun ◽  
Lin Gao ◽  
Zhuang Ma ◽  
Xingwei Xue
Keyword(s):  
Uniaxial Compression ◽  
Creep Behaviour ◽  
Viscoelastic Model ◽  
Asphalt Mixture ◽  
Discrete Element ◽  
Creep Tests ◽  
Burger Model ◽  
Air Voids ◽  
Compression Creep ◽  
Asphalt Mortar

A three-dimensional (3D) microstructure-based discrete element (DE) model was developed to study the creep behaviour of high viscoelastic asphalt sand (HVAS) with the uniaxial compression creep tests. The three-point bending creep tests of asphalt mortar were carried out in order to obtain the parameters of the Burger model, to determine the transformation method of macroscopic parameters and microscopic parameters of the model in theory, to obtain the parameters used in the discrete element model, and then establish the discrete element analysis model for the asphalt mixture. A 3D-DE digital specimen was composed of coarse aggregates, asphalt mortar and air voids, which could also take gradation, irregular shape, random distribution of aggregate and air voids into consideration, and the boundary conditions of the model were set through the simulation of the uniaxial compression creep tests. An accurate and extensive mapping model of HVAS was built by 3D-PFC (Particle Flow Code), which can provide a simple alternative to the laboratory tests. This method can simulate a series of numerical examples based on different stress levels, coarse aggregate homogenizations, mortar homogenizations and temperatures in a single factor method. Comparison of results of laboratory and numerical tests shows that the 3D-PFC-viscoelastic model can reflect the creep mechanical behaviour of asphalt mixture accurately. It provides the theoretical basis and auxiliary means for analysing the mechanical properties of asphalt mixtures using PFC software. The research on creep behaviour of the asphalt mixture by numerical simulation opens up a new way for the research on creep behaviour of the asphalt mixture, it is of considerable theoretical value and has broad application prospects.

Uniaxial Compression Creep Prediction of Asphalt Mixture Using the Eshelby Equivalent Inclusion Method

2014 ◽  
Vol 1061-1062 ◽  
pp. 410-413 ◽  
Author(s):  
Jun Wu
Keyword(s):  
Uniaxial Compression ◽  
Asphalt Mixture ◽  
Stress Conditions ◽  
Creep Tests ◽  
Two Phase ◽  
Asphalt Mastic ◽  
Compression Creep ◽  
Equivalent Inclusion Method ◽  
The Matrix ◽  
Constitutive Parameters

Asphalt mixture was simply treated as a two-phase composite, in which coarse aggregates are embedded into asphalt mastic matrix. According to the elastic-viscoelastic correspondence principle, an elastic micromechanical method is extended for predicting viscoelastic properties of asphalt mixture, which is simply treated as elastic coarse aggregate inclusions periodically and isotropically embedded into viscoelastic asphalt mastic matrix. The Burgers model is adopted for characterizing the matrix mechanical behavior, so that the homogenized relaxation modulus of asphalt mixture in compression creep is derived. After a series of uniaxial compression creep tests are performed on asphalt mastic in different stress conditions in order to determine the matrix constitutive parameters, the presented framework is validated by comparison with the experiment, and then some predictions to uniaxial compression creep behavior of asphalt mixture in different stress conditions are given.

A Three-Dimensional Aggregate Generation and Packing Algorithm for Modeling Asphalt Mixture with Graded Aggregates

2010 ◽  
Vol 26 (2) ◽  
pp. 165-171 ◽  
Author(s):  
R. Xu ◽  
X.H. Yang ◽  
A.Y. Yin ◽  
S.F. Yang ◽  
Y. Ye
Keyword(s):  
Elastic Properties ◽  
Uniaxial Compression ◽  
Mechanical Performance ◽  
Asphalt Mixture ◽  
Three Dimensional ◽  
Packing Algorithm ◽  
Aggregate Base ◽  
Aggregate Shape ◽  
Mixture Samples ◽  
Convex Control

AbstractA three-dimensional aggregate generation and packing algorithm applicable for modeling asphalt mixture with high content of graded aggregates is presented in this paper. In the algorithm, arbitrary-shaped polyhedra are used to model aggregates, so that the effect of aggregate shape on the mechanical performance of asphalt mixture can be considered. The algorithm consists of two steps: Aggregate generation and packing. Polyhedra are created by extending triangular fundaments and treated as visualized aggregates after passing through convex control and sharpness judgment. After that, graded aggregates are taken out from the aggregate base and randomly packed in a given cylindrical or cubical region one by one equiprobably. Overlapping between nearby aggregates is avoided by the help of Boolean partition operation in ANSYS. Finally, some asphalt mixture samples with a given gradation are modeled as examples, and their effective elastic properties and creep behaviors under uniaxial compression are simulated.

scholarly journals Does the Permanent Creep-Rate of Polycrystalline Ice Increase with Crystal Size?

1980 ◽  
Vol 25 (91) ◽  
pp. 151-158 ◽  
Author(s):  
Paul Duval ◽  
Hugues Le Gac
Keyword(s):  
Grain Size ◽  
Creep Rate ◽  
Uniaxial Compression ◽  
Crystal Size ◽  
Size Range ◽  
Transient Creep ◽  
Creep Tests ◽  
Compression Creep ◽  
Polycrystalline Ice

AbstractUniaxial compression creep tests were performed on artificial and natural polycrystalline ices at temperatures near –7°C. The grain-size range investigated was from 1 to 10 mm. Contrary to previous results, the permanent creep-rate was not found to increase with crystal size. Only the transient creep appears to be sensitive to variations in crystal size.

scholarly journals Transversely Isotropic Creep Characteristics and Damage Mechanism of Layered Phyllite Under Uniaxial Compression Creep Test

2021 ◽  
Author(s):  
Jiabing Zhang ◽  
Xiaohu Zhang ◽  
Zhen Huang ◽  
Helin Fu
Keyword(s):  
Steady State ◽  
Uniaxial Compression ◽  
Creep Deformation ◽  
Transversely Isotropic ◽  
Damage Mechanism ◽  
Steady State Creep ◽  
Creep Stage ◽  
Compression Creep ◽  
Bedding Angle ◽  
Creep Characteristics

Abstract The layered surrounding rocks of deep tunnels undergo large creep deformation due to the presence of planes of weakness and the presence of prolonged high in-situ stress, thereby the deformation severely endangers the safety of tunnels. This study conducts uniaxial compression creep tests to experimentally investigate the transversely isotropic creep characteristics and the damage mechanism of layered phyllite samples having bedding angles of 0°, 22.5°, 45°, 67.5°, and 90°. The results indicate that the creep deformation of the specimens takes place in four stages: the instantaneous elastic deformation stage, the deceleration creep stage, the steady-state creep stage, and the accelerated creep stage. The cumulative creep deformation and the creep time during the steady-state creep stage of the specimens initially decrease and then increase as the bedding angle changes from 0° to 90°, thereby, corresponding to the initial increase and subsequent decrease in creep rate during the deceleration creep stage. Based on the existing viscoelastic-plastic damage creep model, the creep parameters E1, E2, η2, and η3 are observed to initially decrease and then increase with the increase in bedding angle, hence demonstrating that the creep characteristics and damage mechanism of the layered rock mass are controlled by the effect of the natural weakness planes and show significant transversely isotropic characteristics.

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