اثر چرخه انجماد - ذوب بر چقرمگی شکست و پارامترهای مقاومتی سنگ تراورتن

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده فنی و مهندسی، دانشگاه بین‌المللی امام خمینی (ره)، قزوین، ایران

چکیده

در ﺣﺎل ﺣﺎﺿﺮ، ﺑﺎ ﺗﻮﺳﻌﻪ ﻣﺪاوم اﻗﺘﺼﺎد در ﻣﻨﺎﻃﻖ ﺳﺮدﺳﯿﺮ در ﺳﺮاﺳﺮ ﺟﻬﺎن، ﺑﺴﯿﺎری از ﭘﺮوژهﻫﺎی ﺳﻨﮕﯽ از ﻗﺒﯿﻞ اﺳﺘﺨﺮاج ﻣﻌﺎدن و اﮐﺘﺸـﺎف  ﻧﻔـﺖ و ﮔـﺎز در این ﻣﻨﺎﻃﻖ در ﺣﺎل اﺟﺮا اﺳﺖ. در اﺳﺘﺎن‌ﻫﺎی ﺷﻤﺎل ﻏﺮب و ﻏﺮب اﯾﺮان ﮐﻪ دارای ﺗﺎﺑﺴﺘﺎنﻫﺎی ﻣﻌﺘﺪل و زﻣﺴﺘﺎن‌ﻫﺎی ﺳﺮد می‌‌باشند، ﺑﺎرﻧـﺪﮔﯽ زﯾـﺎد و ﺑـﺮودت ﻫـﻮا از ﻣﺸﺨﺼﺎت زﻣﺴﺘﺎن‌ﻫﺎی اﯾﻦ ﻣﻨﺎﻃﻖ ﺑﻪ ﺷﻤﺎر ﻣﯽ‌آﯾﺪ. در اﯾﻦ ﺷﺮاﯾﻂ ﺳﻨﮓ ﺗﺤﺖ ﺗﺄﺛﯿﺮ ﯾﺨﺒﻨﺪان‌ﻫﺎی ﻃﻮﻻﻧﯽ و چرخه­های ﻣﺘﻌﺪد ﯾﺨﺒﻨﺪان - ذوب ﻗﺮار می‌گیرد. ﺑﻨﺎﺑﺮاﯾﻦ در ﻣﻨﺎﻃﻘﯽ ﮐﻪ اﺣﺘﻤﺎل رخ دادن اﯾﻦ ﻓﺮآﯾﻨﺪ اﺳﺖ ﺿﺮوری اﺳﺖ ﺗﺎ ﺗﺄﺛﯿﺮ چرخه­ های ﻣﺘﻌﺪد ﯾﺨﺒﻨﺪان - ذوب ﺑﺮ روی وﯾﮋﮔﯽﻫﺎی ﻓﯿﺰﯾﮑﯽ و ﻣﮑﺎﻧﯿﮑﯽ ﻣﺼﺎﻟﺢ در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﻮد. در این پژوهش به بررسی تاثیر فرآیند یخبندان- ذوب روی چقرمگی شکست مود Ι و Π و پارامترهای مقاومتی سنگ تراورتن پرداخته شده است. بدین منظور، برای بررسی اثر چرخه­های یخبندان- ذوب بر چقرمگی شکست مود Ι و Π، نمونه‌ها تحت 0، 1، 4، 8، 16، 32 و 64 چرخه­ یخبندان- ذوب قرار گرفته، و چقرمگی شکست مود Ι و Π در چرخه‌های ﻣﺨﺘﻠﻒ ﺑﺮرﺳﯽ ﺷﺪه اﺳﺖ. برای بررسی اثر یخبندان- ذوب روی پارامترهای مقاومتی سنگ تراورتن، نمونه‌ها تحت فشار محصور کننده 0،  2/5 و 5 مگاپاسکال قرار گرفته‌اند. همچنین برای بررسی و ارزیابی دقیق­تر تغییرات ساختاری نمونه‌ها در اثر اعمال چرخه­ های یخبندان- ذوب مطالعات میکروسکوپی نیز انجام گرفت. نتایج نشان می‌دهد که با افزایش تعداد چرخه ­های یخبندان- ذوب چقرمگی شکست مود Ι و Π به صورت نمایی کاهش می‌یابد. چقرمگی شکست مود I تراورتن سفید و قهوه ­ای بعد از 64 سیکل نسبت به سیکل صفر به ترتیب 35/48 و 37 درصد و چقرمگی شکست مود II تراورتن سفید و قهوه­ای بعد از 64 سیکل نسبت به سیکل صفر به ترتیب 45/75 و 50 درصد کاهش یافت. مقاومت فشاری سه محوری، مقاومت فشاری تک محوری، چسبندگی و زاویه اصطکاک داخلی با افزایش تعداد سیکل یخبندان- ذوب نسبت به سیکل صفر  نیز کاهش می‌باید. مطالعات میکروسکوپی نشان می‌دهد، میکروترک‌های موجود در سنگ در اثر چرخه­های یخبندان- ذوب گسترش یافته و ترک‌های جدید به وجود آمده است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Effect of Freeze-Thaw Cycles on Fracture Toughness and Strength Parameters of Travertine

نویسندگان [English]

  • Fardin Nezamivan Chegini
  • Mehdi Hosseini
Imam Khomeini international university
چکیده [English]

The present research investigates the effect of freeze-thaw cycles on mode I and mode II fracture toughness and strength parameters of travertine. In order to investigate the effect of freeze-thaw cycles on mode I and mode II fracture toughness, the samples were exposed to 0, 1, 4, 8, 16 and 32 freeze-thaw cycles and mode I and mode II fracture toughness were studied in different cycles. Confining pressures of 0, 2.5 and 5 MPa were applied to the samples to explore the effect of freeze-thaw cycles on strength parameters of travertine. Furthermore, microscopic studies were conducted to more precisely examine and evaluate the structural changes of the samples due to freeze-thaw cycles. Results show that mode I and mode II fracture toughness decrease exponentially as the number of freeze-thaw cycles increases. Mode I fracture toughness of the white and brown travertine were decreased after 64 cycles compared to 0 cycle as much as 35.48 and 37 percent, respectively and mode II fracture toughness of the white and brown travertine were decreased after 64 cycles compared to 0 cycle as much as 45.75 and 50 percent, respectively. Moreover, as the number of freeze-thaw cycles increases, triaxial compressive strength, uniaxial compressive strength, cohesion and internal friction angle decrease with regard to 0 cycle. Microscopic studies revealed that due to the freeze-thaw cycles, the microcracks of the stones propagate and new cracks are developed.

کلیدواژه‌ها [English]

  • Freeze-thaw cycle
  • Fracture toughness
  • Strength parameters
  • Travertine
[1] D.T. Nicholson, F.H. Nicholson, Physical deterioration of sedimentary rocks subjected to experimental freeze–thaw weathering, Earth Surface Processes and Landforms: The Journal of the British Geomorphological Research Group, 25(12) (2000) 1295-1307.
[2] G. Zappia, C. Sabbioni, C. Riontino, G. Gobbi, O. Favoni, Exposure tests of building materials in urban atmosphere, Science of the total environment, 224(1-3) (1998) 235-244.
[3] J.R. Dunn, P.P. Hudec, Water, clay and rock soundness, (1966).
[4] D. Everett, Complementary information to capillary properties of some model pore systems with special reference to frost damage, Rilem Bulletin, (27) (1965).
[5] A. Prick, Dilatometrical behaviour of porous calcareous rock samples subjected to freeze-thaw cycles, Catena, 25(1-4) (1995) 7-20.
[6] M. Nakamura, T. Togaya, S. Okuda, Effect of dimensional distribution of pores in porous ceramics on frost resistance under one dimensional cooling. Yogyo – Kyokai – Shi, 85 (1997) 549-554.
[7] J. Walder, B. Hallet, A theoretical model of the fracture of rock during freezing, Geological Society of America Bulletin, 96(3) (1985) 336-346.
[8] M. Mutlutürk, R. Altindag, G. Türk, A decay function model for the integrity loss of rock when subjected to recurrent cycles of freezing–thawing and heating–cooling, International journal of rock mechanics and mining sciences, 41(2) (2004) 237-244.
[9] R. Altindag, M. Mutlutürk, R. Karaguzel, The effects of freezing–thawing cycles on the use ability of Isparta andesite as a building stone, in:  Proceedings of International Symposium on Industrial Minerals and Building Stones, 2003, pp. 289.
[10] R. Altindag, I. Alyildiz, T. Onargan, Mechanical property degradation of ignimbrite subjected to recurrent freeze–thaw cycles, International journal of rock mechanics and mining sciences, 41(6) (2004) 1023-1028.
[11] A. Jamshidi, M.R. Nikudel, M. Khamehchiyan, Predicting the long-term durability of building stones against freeze–thaw using a decay function model, Cold Regions Science and Technology, 92 (2013) 29-36.
[12] A. Momeni, Y. Abdilor, G. Khanlari, M. Heidari, A. Sepahi, The effect of freeze–thaw cycles on physical and mechanical properties of granitoid hard rocks, Bulletin of Engineering Geology and the Environment, 75(4) (2016) 1649-1656.
[13] J. Yu, X. Chen, H. Li, J.-w. Zhou, Y.-y. Cai, Effect of freeze-thaw cycles on mechanical properties and permeability of red sandstone under triaxial compression, Journal of Mountain Science, 12(1) (2015) 218-231.
[14] G. Khanlari, R.Z. Sahamieh, Y. Abdilor, The effect of freeze–thaw cycles on physical and mechanical properties of Upper Red Formation sandstones, central part of Iran, Arabian Journal of Geosciences, 8(8) (2015) 5991-6001.
[15] J.-l. Li, K.-p. Zhou, W.-j. Liu, H.-w. Deng, NMR research on deterioration characteristics of microscopic structure of sandstones in freeze–thaw cycles, Transactions of Nonferrous Metals Society of China, 26(11) (2016) 2997-3003.
[16] A. Özbek, Investigation of the effects of wetting–drying and freezing–thawing cycles on some physical and mechanical properties of selected ignimbrites, Bulletin of Engineering Geology and the Environment, 73(2) (2014) 595-609.
 [17] M. Hosseini, A. Khodayari, Effect of freeze-thaw cycle on strength and rock strength parameters (A Lushan sandstone case study), Journal of Mining and Environment, 10(1) (2019) 257-270.
[18] T. Han, J. Shi, X. Cao, Fracturing and damage to sandstone under coupling effects of chemical corrosion and freeze–thaw cycles, Rock Mechanics and Rock Engineering, 49(11) (2016) 4245-4255.
[19] J. Ni, Y.-L. Chen, P. Wang, S.-R. Wang, B. Peng, R. Azzam, Effect of chemical erosion and freeze–thaw cycling on the physical and mechanical characteristics of granites, Bulletin of Engineering Geology and the Environment, 76(1) (2017) 169-179.
[20] K. Abdolghanizadeh, M. Hosseini, M. Saghafiyazdi, Effects of number of freeze-thaw cycles and freezing temperature on mode I and mode II fracture toughness of cement mortar, Journal of Mining and Environment, 10(4) (2019) 967-978.
[21] S.Z.S. Mousavi, H. Tavakoli, P. Moarefvand, M. Rezaei, Assessing the effect of freezing-thawing cycles on the results of the triaxial compressive strength test for calc-schist rock, International Journal of Rock Mechanics and Mining Sciences, 123 (2019) 104090.
[22] M. Hosseini, A. Ahmari, The effect of freezing temperature in the freeze-thaw process on the Physical and Mechanical properties of sandstone, New Findings in Applied Geology, 15(29) (2021) 122-134.
[23] L. Chen, K. Li, G. Song, D. Zhang, C. Liu, Effect of freeze–thaw cycle on physical and mechanical properties and damage characteristics of sandstone, Scientific Reports, 11(1) (2021) 1-10.
[24] Z. Su, K. Geng, F. Zhou, J. Sun, H. Yu, Influence of Freeze-Thaw Cycles on Acoustic Emission Characteristics of Granite Samples under Triaxial Compression, Advances in Civil Engineering,  (2021).
[25] M. Aliha, M. Ayatollahi, Rock fracture toughness study using cracked chevron notched Brazilian disc specimen under pure modes I and II loading–A statistical approach, Theoretical and Applied Fracture Mechanics, 69 (2014) 17-25.
[26] ISRM, Rock characterization, testing and monitoring, in, Pergamon Press Oxford, 1981, pp. 211.
[27] R. Fowell, J. Hudson, C. Xu, X. Zhao, Suggested method for determining mode I fracture toughness using cracked chevron notched Brazilian disc (CCNBD) specimens, in:  International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts, 1995, pp. 322A.
[28] A. Jamshidi, M.R. Nikudel, M. Khamehchiyan, A novel physico-mechanical parameter for estimating the mechanical strength of travertines after a freeze–thaw test, Bulletin of Engineering Geology and the Environment, 76(1) (2017) 181-190.