DEM approach for engineering aggregate gradation and shape properties influencing mechanical behavior of unbound aggregate materials

Yuanjie Xiao, Erol Tutumluer, Yu Qian

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

It has been well established that the mechanical behavior of unbound aggregate materials is strongly influenced by the shape of the particles and the complete grain size distribution (i.e., gradation). This paper presents the use of an image-aided discrete element method (DEM) approach to realistically model the micromechanical interactions of aggregate particles including size and shape effects. A realistic unbound aggregate model is developed from previous studies to simulate triaxial compression tests based on the DEM approach and the innovative use of membrane elements surrounding the cylindrical aggregate specimen in the DEM model. To calibrate the DEM model, six different types of aggregates were used to prepare samples of 21 unbound aggregate blends at the same gradation and voids content but different crushed percentages. The shape properties of flatness and elongation, surface texture, and angularity were quantified by imaging then correlated to strength and permanent deformation characteristics obtained from triaxial testing. The experimental test results are utilized to determine required parameters for the discrete element model by minimizing the differences between DEM-simulated triaxial shear strength results and experimental ones. It is found that the developed DEM model is not only capable of reproducing the typical shear strength behavior of different unbound aggregate materials with varying shape properties, but also has the potential for optimizing the selection of size and shape properties of various unbound aggregates to achieve desired shear strength (or rutting resistance) and hydraulic behavior for open-graded permeable aggregate base.

Original languageEnglish (US)
Title of host publicationGeo-Congress 2014 Technical Papers
Subtitle of host publicationGeo-Characterization and Modeling for Sustainability - Proceedings of the 2014 Congress
PublisherAmerican Society of Civil Engineers (ASCE)
Pages2898-2910
Number of pages13
Edition234 GSP
ISBN (Print)9780784413272
DOIs
StatePublished - Jan 1 2014
Event2014 Congress on Geo-Characterization and Modeling for Sustainability, Geo-Congress 2014 - Atlanta, GA, United States
Duration: Feb 23 2014Feb 26 2014

Publication series

NameGeotechnical Special Publication
Number234 GSP
ISSN (Print)0895-0563

Other

Other2014 Congress on Geo-Characterization and Modeling for Sustainability, Geo-Congress 2014
CountryUnited States
CityAtlanta, GA
Period2/23/142/26/14

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Architecture
  • Building and Construction
  • Geotechnical Engineering and Engineering Geology

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  • Cite this

    Xiao, Y., Tutumluer, E., & Qian, Y. (2014). DEM approach for engineering aggregate gradation and shape properties influencing mechanical behavior of unbound aggregate materials. In Geo-Congress 2014 Technical Papers: Geo-Characterization and Modeling for Sustainability - Proceedings of the 2014 Congress (234 GSP ed., pp. 2898-2910). (Geotechnical Special Publication; No. 234 GSP). American Society of Civil Engineers (ASCE). https://doi.org/10.1061/9780784413272.281