Hydro-mechanical behavior of unsaturated unbound pavement materials under repeated and static loading

Ehsan Yaghoubi, Mahdi M. Disfani, Arul Arulrajah, Jayantha Kodikara, Asmaa Al-Taie

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


Climatic events such as precipitation result in unbound structural layers of pavements being in a partially saturated condition during their service life. With unsaturated testing being relatively complex and costly, the presence of relatively low matric suction in granular geomaterials, practitioners have been reluctant to explore the utilization of unsaturated geomechanics in the analysis and design of the mechanical behavior of pavement structural layers. In this research, unsaturated mechanical characteristics of three types of recycled geomaterials were firstly investigated using repeated load triaxial testing and the incorporation of their soil–water characteristics in the analysis of their resilient moduli response. This was to demonstrate the importance of understanding the unsaturated mechanical behavior of compacted granular material. Next, a virgin compaction surface (VCS) was developed within a moisture content-based framework to interpret the loading, unloading and wetting-induced volume change of the compacted materials. Outcomes of this research, for the first time, extend the application of the well-established Monash Peradeniya Kodikara (MPK) framework, originally developed for fine cohesive soils, to granular materials. A distinctive attribute of the proposed approach is the relative simplicity in the testing methodology by utilizing the conventional geotechnical testing equipment. The findings of this research can be used for estimation of the settlement of a granular structural layer that is compacted, loaded and then wetted through precipitation or flooding.

Original languageEnglish
Title of host publicationAdvances in Transportation Geotechnics IV - Proceedings of the 4th International Conference on Transportation Geotechnics Volume 3
EditorsErol Tutumluer, Soheil Nazarian, Imad Al-Qadi, Issam I. A. Qamhia
Number of pages14
ISBN (Print)9783030772376
Publication statusPublished - 2022
EventInternational Conference on Transportation Geotechnics 2021 - Virtual, United States of America
Duration: 24 May 202127 May 2021
Conference number: 4th
https://conferences.illinois.edu/ICTG2021/ (Website)

Publication series

NameLecture Notes in Civil Engineering
ISSN (Print)2366-2557
ISSN (Electronic)2366-2565


ConferenceInternational Conference on Transportation Geotechnics 2021
Abbreviated titleICTG 2021
Country/TerritoryUnited States of America
Internet address


  • Matric suction
  • MPK framework
  • Resilient modulus response
  • Unbound pavement materials
  • Volumetric behavior

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