بررسی آزمایشگاهی شرایط تثبیت شیمیایی-مکانیکی و دوام آزمونه های ماسه SPتحت اثر دوره های یخبندان-ذوب

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه مهندسی عمران، دانشکده مهندسی، دانشگاه صنعتی، کرمانشاه، ایران،

2 گروه مهندسی عمران، دانشگاه بوعلی سینا همدان، ایران

چکیده

بروز یخ بندان و متعاقب آن ذوب شدن یخ، سالیانه خسارات زیادی به بسترهای متشکل از خاک های ماسه ریزدانه وارد می کند. تغییرات حجمی خاک در حین یخ زدن-آب شدن عاملی است که باعث کاهش مقاومت و افزایش تغییرشکل ها می شود. در این مطالعه، اندازه گیری های متعدد آزمایشگاهی برای بررسی اثرات چرخه های یخبندان-ذوب بر رفتار آزمونه های استوانه ای ماسه ای ارائه شده است. برای بررسی دقیق اثرات یخزدگی، ماسه ریزدانه انتخاب شده است. به صورت همزمان روش های تثبیت شیمیایی خاک توسط اختلاط با سیمان با مقادیر 2، 4 و 6 درصد وزنی خاک خشک و تسلیح مکانیکی با افزودن 0، 0/5 و 1 درصد وزنی الیاف بازیافتی نایلونی، بکار گرفته شده است.  این مطالعه نشان می دهد که وجود الیاف در کنار سیمان، باعث تغییرات آشکار مشخصات سختی، مقاومتی و دوام نمونه ها تحت اثر چرخه های یخبندان-ذوب می شود. از یافته های این مطالعه می توان نتیجه گرفت که در نمونه‌های بدون الیاف، ترک‌های مشخص و عریض مشاهده می‌گردد. درصورتی‌که در نمونه‌های مسلح به الیاف ترک‌ها ریزتر هستند و در عرض گسترده‌تری توزیع شده‌اند. نتایج مربوط به رفتار نمونه‌ها در هنگام بارگذاری نشان داد که در نمونه‌های مسلح شده با الیاف، گسیختگی بر اثر بیرون‌زدگی الیاف رخ داده است. در نمونه‌های 7 روزه خشک (بدون اعمال چرخه یخبندان -ذوب) با افزودن الیاف مقاومت فشاری نمونه‌ها افزایش می‌یابد. در نمونه‌های 28 روزه، با افزایش فقط 0/5% الیاف به طول0/5 سانتی‌متر، افزایش مقاومت فشاری محدود نشده و از آن ‌پس کاهش آن مشاهده شده است. در تمام نمونه‌های 7 و 28 روزه خشک، با افزایش اندازه الیاف از0/5 سانتی‌متر به 1 و 1/5 سانتی‌متر مقاومت فشاری نمونه‌ها روندی کاهشی دارد. همچنین با افزودن درصد الیاف از 0/5 به 1% باز هم روند کاهش مقاومت دیده می‌شود.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Laboratory investigation of chemical-mechanical stabilization conditions and durability of SP sand samples under the effect of freeze-thaw periods

نویسندگان [English]

  • Yazdan Shams Maleki 1
  • Azadeh Dadfarin 2
  • Mehdi Esna ashari 2
1 Civil Engineering department, Engineering Faculty, Kermanshah University of Technology (KUT), Kermanshah, Iran
2 Civil Engineering Department, Bu-Ali Sina University, Hamedan, Iran
چکیده [English]

The occurrence of ice lenses and the subsequent melting of the ice causes a lot of damage to the beds consisting of fine sand soils every year. Volumetric changes of soil during freezing-thawing is a factor that reduces soil strength and increases deformations. In this study, several laboratory measurements are presented to investigate the effects of freeze-thaw cycles on the behavior of cylindrical sand-cement-fiber specimens. Fine-grained sand has been chosen to investigate the effects of freeze-thaw. At the same time, chemical stabilization methods of soil by mixing with cement with amounts of 2, 4, and 6% by weight of dry soil and mechanical reinforcement by adding 0, 0.5, and 1% by weight of recycled nylon fibers have been used. This study shows that the presence of fibers next to cement causes obvious changes in the stiffness, strength, and durability characteristics of the samples under the effect of freeze-thaw cycles. From the findings of this study, it can be concluded that in samples without fibers, distinct and wide cracks are observed. While, in samples armed with fibers, the cracks are smaller and distributed in a wider width. The results related to the behavior of the samples during loading showed that in the samples reinforced with fibers, failure occurred due to the pull-out of the fibers. In 7-day dry samples (without the freezing-thawing cycle effect), the compressive strength of the samples increases with the addition of fibers. In the 28-day samples, with an increase of only 0.5% of fibers with a length of 0.5cm, the unconfined compressive strength increased , and its decrease was observed after that. In all 7d and 28d dry samples, with the increase of fiber size from 0.5cm to 1 and 1.5cm, the compressive strength of the samples has a decreasing trend. Also, by adding the percentage of fibers from 0.5 to 1%, the trend of decreasing strength of the specimens can be seen.

کلیدواژه‌ها [English]

  • Fine sand
  • chemical stabilization
  • fiber reinforcement
  • freeze-thaw
  • strength-durability

مراجع

[1] J. Kaufmann, F. Winnefeld, & D. Hesselbarth, Effect of the addition of ultrafine cement and short fiber reinforcement on shrinkage, rheological and mechanical properties of Portland cement pastes. Cement and Concrete Composites, 26(5), 541-549 (2004).
[2] J.K. Liu, and L.Y. Peng, Experimental study on the unconfined compression of a thawing soil. Cold Regions Science and Technology., Vol. 58, 92-9 (2009).
[3] K.L. Lee, B.D. Adams, & J.M.J. Vagneron, Reinforced earth retaining walls. Journal of the Soil Mechanics and Foundations Division, 99(10), 745-764 (1973).
[4] D.H. Gray, & H. Ohashi, Mechanics of fiber reinforcement in sand, Journal of Geotechnical Engineering, 109(3), 335-353 (1983).
[5] D.R. Freitag, Soil randomly reinforced with fibers, Journal of Geotechnical Engineering, 112(8), 823-826 (1986).
[6] R.L. Michalowski, & J. C̆ermák, Strength anisotropy of fiber-reinforced sand, Computers and Geotechnics, 29(4), 279-299 (2002).
[7] T. Yetimoglu, & O. Salbas, A study on shear strength of sands reinforced with randomly distributed discrete fibers, Geotextiles and Geomembranes, 21(2), 103-110 (2003).
[8] T. Yetimoglu, M. Inanir, & O.E. Inanir, A study on bearing capacity of randomly distributed fiber-reinforced sand fills overlying soft clay, Geotextiles and Geomembranes, 23(2), 174-183 (2005).
[9] E. Ibraim, & S. Fourmont, S., Behaviour of sand reinforced with fibres. In Soil Stress-Strain Behavior: Measurement, Modeling and Analysis, Springer Netherlands, 807-818 (2007).
[10] M. Asadi, Investigating the mechanical characteristics of soil reinforced with tire cords waste, Master's thesis, Faculty of Engineering, Bu-Ali Sina University, Hamedan (2007) (in Persian).
[11] B.V.S. Viswanadham, B.R. Phanikumar, & R.V. Mukherjee, R. V., Swelling behaviour of a geofiber-reinforced expansive soil, Geotextiles and Geomembranes, 27(1), 73-76 (2009).
[12] F. Mirzaei, Investigating the effect of tire cord fibers on the stress-strain behavior and shear strength of reinforced sandy soil, Master's thesis, Faculty of Engineering, Bu-Ali Sina University, Hamedan (2009) (in Persian).
[13] J. Dupas, A. Pecker, Static and dynamic properties of sand-cement, Journal of Geotechnical Engineering, 105(3), 419-436 (1979).
[14] G.W. Clough, N. Sitar, R.C. Bachus, and N.S. Rad, Cemented sands under static loading, Journal of Geotechnical and Geoenvironmental Engineering, 799-817 (1981).
[15] G.M. Filz, and J.K. Mitchell, Design, Construction, and Performance of Soil- and Cement-Based Vertical Barriers, International Containment Technology Conference, Ralph R. Rumer and James K. Mitchell, Eds., US DoE, US EPA, and Dupont Company, Baltimore, MD, pp 63 (1995).
[16] C.J. Miller, & S. Rifai, Fiber reinforcement for waste containment soil liners, Journal of Environmental Engineering, 130(8), 891-895 (2004).
[17] J.C. Morel, & J.P. Gourc, Mechanical behavior of sand reinforced with mesh elements, Geosynthetics International, 4(5), 481-508 (1997).
[18] K.S. Heineck, M.R. Coop, & N.C. Consoli, Effect of microreinforcement of soils from very small to large shear strains. Journal of geotechnical and geoenvironmental engineering, 131(8), 1024-1033 (2005).
[19] J. Liu, Y. Bai, Z. Song, D.P. Kanungo, Y. Wang, F. Bu, Z. Chen, X. Shi, Stabilization of sand using different types of short fibers and organic Polymer, Construction and Building Materials, 253 (2020) 119164.
[20] P. Chindaprasirt, P. Jamsawang, P. Sukontasukkul, P. Jongpradist, S. Likitlersuang, Comparative mechanical performances of cement-treated sand reinforced with fiber for road and pavement applications, Transportation Geotechnics, 30 (2021) 100626.
[21] Z. Gao, M. Huang, Effect of sample preparation method on mechanical behaviour of fibre-reinforced sand, Computers and Geotechnics, 133 (2021) 104007.
[22] U.S. Rima, N. Beier, Effects of multiple freeze-Thaw cycles on oil sand tailings behaviour, Cold Regions Science and Technology, 192 (2021) 103404
[23] M. Sharma, N. Satyam, K.R. Reddy, Effect of freeze-thaw cycles on engineering properties of biocemented sand under different treatment conditions, Engineering Geology, 284 (2021) 106022.
[24] G. Cui, C. Zhu, C. Xi, S. Ma, Z. Liu, D. Zhang, Experimental study of the dynamic characteristics of Songhua River silt with fine grains under freeze-thaw cycles using asymmetric hysteresis, Cold Regions Science and Technology, 196 (2022) 103511.
[25] Z. Tao, Y. Zhang, X. Chen, X. Gu, Effects of freeze-thaw cycles on the mechanical properties of cement-fiber composite treated silty clay, Construction and Building Materials, 316 (2022) 125867.
[26] M. Jafari, M. Esna-ashari, Effect of waste tire cord reinforcement on unconfined compressive strength of lime stabilized clayey soil under freeze-thaw condition, Cold Regions Science and Technology, 82 (2012) 21-29
[27] X. Xiao, J. Li, D. Cai, L. Lou, Y. Shi, F. Xiao, Evolution evaluation of high-speed railway asphalt concrete waterproofing layer during laboratory freeze-thaw cycles, Construction and Building Materials, 324 (2022) 126258.
[28] G. Kamali, M. Habibi Nokhandan, investigation of the spatial and temporal distribution of ice in Iran and its role in road transportation, Transportation Research Journal, second year, number 2, summer (2005) (in Persian).
[29] R. Ismaili, M. Habibi Nokhandan, G. Abbas, Evaluation of changes in the length of the growth period and ice caps caused by climatic fluctuations, a case study: Khorasan Razavi, Natural Geography Research, No. 73, 2010, 69-82 (in Persian).
[30] M. Malek Dost Pishkenari, M. Azadi, M. Ghayoumi, Investigating the effects of thawing and freezing cycles on the deformation parameters of biologically stabilized sand, Journal of Civil and Environmental Engineering, Tabriz University, (2022) (in Persian).
[31] F. Rezaei Moghadam, B. Jafari Nader, T. Rezaei Moghadam, Laboratory investigation of the effect of "Nicoflok" polymer additive on the compressive and tensile strength of desert and coastal wind sand in pavement layers, Amirkabir Civil Engineering Journal, Volume 53, Number 2, 733-774 (2020) (in Persian).
[32] A. Negahdar, S. Yadegari, S. Houshmandi, Investigation of the creep behavior of sandy clay soil under 1D consolidation test, Journal of Civil and Environmental Engineering of Tabriz University, 45.3(80), 65-74 (2015) (in Persian).
[33] A. Negahdar, A. Ahmadi Barough, Mirmahdi Seyedrahimi-Niaraq, Investigation of Frozen Soil Behavior under Unconfined Compression Test, Amirkabir Journal of Civil Engineering, 54(8), 2022, 3083-3096 (in Persian).
[34] J.M. Konrad, M. Samson, Hydraulic conductivity of kaolinite-silt mixtures subjected to closed-system freezing and thaw consolidation, Canadian Geotechnical Journal, 37, 857-869 (2000).
[35] D.Y. Wang, W. Ma, Y.H. Niu, X.X. Chang, and Z. Wen, Effects of cyclic freezing and thawing on mechanical properties of Qinghai-Tibet clay, Cold Regions Science and Technology, 48, 34-43 (2007).
[36] A.M. Tabatabai, Road paving. 13th edition, academic book publication, 2007 (in Persian).
[37] L. Bronfenbrener, The modelling of the freezing process in fine-grained porous media: Application to the frost heave estimation, Cold Regions Science and Technology, 56(2), 120-134 (2009).
[38] E. Penner, Alternate freezing and thawing not a requirement for frost heaving in soils, Canadaian Journal of Soil Science, 41, 160-163 (1960).
[39] D. Sheng, K. Axelsson, and S. Knutsson, Frost heave due to ice lens formation in freezing soils. 1.Theory and verification, Nordic Hydrolgy, Vol.26: 125-146 (1995).
[40] C.A. Anagnostopoulos, & T.T. Papaliangas, Experimental investigation of Epoxy Resin and sand mixes, Journal of Geotechnical and Geoenvironmental Engineering, 138, 841-849 (2012).
نشریه مهندسی عمران امیرکبیر
دوره 55، شماره 8
آبان 1402
صفحه 1601-1624

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