Drained Triaxial Response of Natural Clay Reinforced with Natural Hemp Fibers
Publication: International Journal of Geomechanics
Volume 24, Issue 7
Abstract
Reinforcement of soils with fibers generally increases the mechanical properties of the fiber-reinforced soil (FRS) system. However, published literature is limited to investigating the undrained response of clay and synthetic fibers, with few studies targeting natural clay and natural fibers under drained conditions. There is a need to study the response of fiber-reinforced clay systems under drained conditions to assess long-term stability. This paper investigated the drained shear strength and durability of clays reinforced with natural hemp fibers using isotropically consolidated drained triaxial tests, in which the fiber content, confining pressure, and compaction water content were varied. Results showed that the incorporation of hemp fibers improved the deviatoric stress at failure by up to 60%, which increased the drained cohesion and friction angle of the FRS by 7–10 kPa and 3–7°, respectively. The increase in cohesive intercept was not affected by the compaction water content, while the increase in friction angle was pronounced in specimens compacted at optimum water content (w = 18%). Durability tests showed that the improvement in strength due to hemp fibers diminishes after 3 weeks of curing prior to drained testing, indicating the dramatic negative impact of degradation of natural fibers on the mechanical performance of fiber-reinforced clay and the need for industrial treatment of the fiber.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
All data, models, and codes generated or used during the study appear in the published article.
Acknowledgments
The authors express their gratitude to the Lebanese National Council for Scientific Research and the University Research Board (URB) at the American University of Beirut (AUB) for providing financial support for this research initiative.
Notation
The following symbols are used in this paper:
- Control
- specimens without any fiber reinforcement;
- c′
- cohesion intercept in consolidated drained tests (kPa);
- D
- diameter of the soil specimen;
- L
- length of the soil specimen;
- Lf
- length of the fiber;
- PI
- plasticity index (%);
- S
- degree of saturation (%);
- w
- water content (%);
- Xf
- gravimetric fiber content defined as the ratio of the weight of fibers to the dry weight of soil (%);
- γd
- dry unit weight of the soil (kN/m3);
- ϕ′
- friction angle for consolidated drained tests (°);
- σd
- deviatoric stress (kPa); and
- σn
- applied normal stress (kPa).
References
Abou Diab, A., S. Najjar, and S. Sadek. 2023. “Reliability-based design of infinite frictional slopes reinforced by inclusion of fibers.” In Geo-Risk 2023, Geotechnical Special Publication (GSP 346), 246–256. Reston, VA: ASCE.
Abou Diab, A., S. S. Najjar, S. Sadek, H. Taha, H. Jaffal, and M. Alahmad. 2018. “Effect of compaction method on the undrained strength of fiber-reinforced clay.” Soils Found. 58 (2): 462–480. https://doi.org/10.1016/j.sandf.2018.02.013.
Abou Diab, A., S. Sadek, S. Najjar, and M. H. Abou Daya. 2016. “Undrained shear strength characteristics of compacted clay reinforced with natural hemp fibers.” Int. J. Geotech. Eng. 10 (3): 263–270. https://doi.org/10.1080/19386362.2015.1132122.
Ahmad, M. E., S. Sadek, and S. Najjar. 2019. “Drained triaxial response of clay reinforced with natural hemp fibers.” In Geo-Congress 2019: Soil Improvement, 305–314. Reston, VA: ASCE.
Ammar, A., S. Najjar, and S. Sadek. 2019. “Mechanics of the interface interaction between hemp fibers and compacted clay.” Int. J. Geomech. 19 (4): 04019015. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001368.
Ang, E. C., and J. E. Loehr. 2003. “Specimen size effects for fiber-reinforced silty clay in unconfined compression.” Geotech. Test. J. 26 (2): 191–200.
Consoli, N. C., M. D. T. Casagrande, and M. R. Coop. 2007. “Performance of a fibre-reinforced sand at large shear strains.” Géotechnique 57 (9): 751–756. https://doi.org/10.1680/geot.2007.57.9.751.
Correia, N. S., S. A. Rocha, P. C. Lodi, and J. S. McCartney. 2021. “Shear strength behavior of clayey soil reinforced with polypropylene fibers under drained and undrained conditions.” Geotext. Geomembr. 49 (5): 1419–1426. https://doi.org/10.1016/j.geotexmem.2021.05.005.
Dittenber, D. B., and H. V. S. Gangarao. 2012. “Critical review of recent publications on use of natural composites in infrastructure.” Composites, Part A 43 (8): 1419–1429. https://doi.org/10.1016/j.compositesa.2011.11.019.
Gregory, G. H. 2006. “Shear strength, creep and stability of fiber-reinforced soil slopes.” Ph.D. dissertation, Dept. of Civil and Geotechnical Engineering, Oklahoma State Univ.
Gregory, G. H., and D. S. Chill. 1998. “Stabilization of earth slopes with fiber reinforcement.” In Proc., 6th Int. Conf. on Geosynthetics, 1073–1078. Austin, TX: International Geosynthetics Society.
Gui, Y., W. Y. Wong, and C. Gallage. 2022. “Effectiveness and sensitivity of fiber inclusion on desiccation cracking behavior of reinforced clayey soil.” Int. J. Geomech. 22 (3): 06021040. https://doi.org/10.1061/(ASCE)GM.1943-5622.0002278.
Heineck, K. S., M. R. Coop, and N. C. Consoli. 2005. “Effect of microreinforcement of soils from very small to large shear strains.” J. Geotech. Geoenviron. Eng. 131 (8): 1024–1033. https://doi.org/10.1061/(ASCE)1090-0241(2005)131:8(1024).
Kaur, T., S. Kumar, and A. K. Singh. 2018. “Love wave propagation in vertical heterogeneous fiber-reinforced stratum imperfectly bonded to a micropolar elastic substrate.” Int. J. Geomech. 18 (2): 04017146. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001006.
Maher, M. H., and D. H. Gray. 1990. “Static response of sands reinforced with randomly distributed fibers.” J. Geotech. Eng. 116 (11): 1661–1677. https://doi.org/10.1061/(ASCE)0733-9410(1990)116:11(1661).
Michalowski, R. L. 2008. “Limit analysis with anisotropic fibre-reinforced soil.” Geotechnique 58 (6): 489–501. https://doi.org/10.1680/geot.2008.58.6.489.
Michalowski, R. L., and J. Čermák. 2002. “Strength anisotropy of fiber-reinforced sand.” Comput. Geotech. 29 (4): 279–299. https://doi.org/10.1016/S0266-352X(01)00032-5.
Michalowski, R. L., and J. Čermák. 2003. “Triaxial compression of sand reinforced with fibers.” J. Geotech. Geoenviron. Eng. 129 (2): 125–136. https://doi.org/10.1061/(ASCE)1090-0241(2003)129:2(125).
Najjar, S. S., S. Sadek, and A. Alcovero. 2013. “Quantification of model uncertainty in shear strength predictions for fiber-reinforced sand.” J. Geotech. Geoenviron. Eng. 139 (1): 116–133. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000742.
Najjar, S. S., S. Sadek, and H. Taha. 2014. “Use of hemp fibers in sustainable compacted clay systems.” In Geo-Congress 2014, 1415–1424. Reston, VA: ASCE. https://doi.org/10.1061/9780784413272.138.
Sadek, S., S. S. Najjar, and F. Freiha. 2010. “Shear strength of fiber-reinforced sands.” J. Geotech. Geoenviron. Eng. 136 (3): 490–499. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000235.
Salaou, N. M. L., J. Thuo, C. Kabubo, and Z. A. Gariy. 2021. “Performance of polypropylene fibre reinforced laterite masonry bricks.” Civ. Eng. Archit. 9 (7): 2178–2186. https://doi.org/10.13189/cea.2021.090707.
Santoni, R. L., and S. L. Webster. 2001. “Airfields and roads construction using fiber stabilization of sands.” J. Transp. Eng. 127 (2): 96–104. https://doi.org/10.1061/(ASCE)0733-947X(2001)127:2(96).
Syed, M., and A. GuhaRay. 2020. “Effect of fiber reinforcement on mechanical behavior of alkali-activated binder-treated expansive soil: Reliability-based approach.” Int. J. Geomech. 20 (12): 04020225. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001871.
Taha, M. M. M., C. P. Feng, and S. H. S. Ahmed. 2020. “Influence of polypropylene fibre (PF) reinforcement on mechanical properties of clay soil.” Adv. Polym. Tech. 2020: 1–15. https://doi.org/10.1155/2020/9512839.
Taha, M. M. M., C.-P. Feng, and S. H. S. Ahmed. 2021. “Modification of mechanical properties of expansive soil from north China by using rice husk Ash.” Materials 14 (11): 2789. https://doi.org/10.3390/ma14112789.
Tang, C., B. Shi, W. Gao, F. Chen, and Y. Cai. 2007. “Strength and mechanical behavior of short polypropylene fiber reinforced and cement stabilized clayey soil.” Geotext. Geomembr. 25 (3): 194–202. https://doi.org/10.1016/j.geotexmem.2006.11.002.
Tiwari, N., N. Satyam, and A. J. Puppala. 2021. “Strength and durability assessment of expansive soil stabilized with recycled ash and natural fibers.” Transp. Geotech. 29: 100556. https://doi.org/10.1016/j.trgeo.2021.100556.
Valipour, M., P. T. Shourijeh, and A. Mohammadinia. 2021. “Application of recycled tire polymer fibers and glass fibers for clay reinforcement.” Transp. Geotech. 27: 100474. https://doi.org/10.1016/j.trgeo.2020.100474.
Vela Silveira, M., J. W. dos S. Ferreira, and M. D. T. Casagrande. 2022. “Effect of surface treatment on natural aging and mechanical behavior of sisal fiber–reinforced sand composite.” J. Mater. Civ. Eng. 34 (6): 06022001. https://doi.org/10.1061/(ASCE)MT.1943-5533.0004237.
Wang, Y., P. Guo, H. Lin, X. Li, Y. Zhao, B. Yuan, Y. Liu, and P. Cao. 2019. “Numerical analysis of fiber-reinforced soils based on the equivalent additional stress concept.” Int. J. Geomech. 19 (11): 04019122. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001504.
Wang, Y.-J., N.-J. Jiang, X.-L. Han, and Y.-J. Du. 2023. “Shear behavior of biochar-amended biocemented calcareous sand treated by biostimulation.” Int. J. Geomech. 23 (1): 04022260. https://doi.org/10.1061/(ASCE)GM.1943-5622.0002634.
Wang, Y.-X., P.-P. Guo, W.-X. Ren, B.-X. Yuan, H.-P. Yuan, Y.-L. Zhao, S.-B. Shan, and P. Cao. 2017. “Laboratory investigation on strength characteristics of expansive soil treated with jute fiber reinforcement.” Int. J. Geomech. 17 (11): 04017101. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000998.
Wu, T. H., P. E. Beal, and C. Lan. 1988. “In-situ shear test of soil-root systems.” J. Geotech. Eng. 114 (12): 1376–1394. https://doi.org/10.1061/(ASCE)0733-9410(1988)114:12(1376).
Yorseng, K., S. M. Rangappa, H. Pulikkalparambil, S. Siengchin, and J. Parameswaranpillai. 2020. “Accelerated weathering studies of kenaf/sisal fiber fabric reinforced fully biobased hybrid bioepoxy composites for semi-structural applications: Morphology, thermo-mechanical, water absorption behavior and surface hydrophobicity.” Constr. Build. Mater. 235: 117464. https://doi.org/10.1016/j.conbuildmat.2019.117464.
Yuan-jun, J., M. Alam, S. Li-Jun, M. Umar, S. Sadiq, L. J. Jia, and M. Rahman. 2022. “Effect of root orientation on the strength characteristics of loess in drained and undrained triaxial tests.” Eng. Geol. 296: 106459. https://doi.org/10.1016/j.enggeo.2021.106459.
Zhao, F., and Y. Zheng. 2022. “Shear strength behavior of fiber-reinforced soil: Experimental investigation and prediction model.” Int. J. Geomech. 22 (9): 04022146. https://doi.org/10.1061/(ASCE)GM.1943-5622.0002502.
Information & Authors
Information
Published In
Copyright
© 2024 American Society of Civil Engineers.
History
Received: May 7, 2023
Accepted: Jan 13, 2024
Published online: Apr 23, 2024
Published in print: Jul 1, 2024
Discussion open until: Sep 23, 2024
ASCE Technical Topics:
- Clays
- Drainage
- Engineering fundamentals
- Engineering materials (by type)
- Fibers
- Geomechanics
- Geotechnical engineering
- Irrigation engineering
- Laboratory tests
- Materials engineering
- Soil dynamics
- Soil mechanics
- Soil properties
- Soil stabilization
- Soil strength
- Soils (by type)
- Tests (by type)
- Triaxial tests
- Water and water resources
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.