بررسی رفتار مکانیکی بتن الیافی حاوی پومیس و متاکائولن و مقاومت شیمیایی آن در برابر حملات اسیدی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار- گروه سازه و زلزله - دانشکده مهندسی عمران، آب و محیط زیست - دانشگاه شهید بهشتی

2 دانشجوی دکترا- دانشکده مهندسی عمران، آب و محیط زیست

3 پژوهشگر، بخش پژوهش و توسعه، شرکت مهندسان مشاور ایمن راه، تهران

چکیده

اخیراً، در روسازی‌های بتنی فرودگاه‌ها و آزادراه‌ها، استفاده از الیاف در بتن برای کاهش ترک‌ها و افزایش فاصله درز اتصالات دال‌های بتنی رواج یافته است. اما، رفتار دوامی آن‌ها در برابر حملات باران‌های اسیدی کمتر مورد مطالعه قرار گرفته است. هدف این مقاله بررسی عملکرد مکانیکی و دوامی بتن تقویت شده با الیاف پلی الفین و پلی‌پروپیلن حاوی 15% مواد پوزولانی (پومیس یا متاکائولن) به‌ جای سیمان پرتلند تیپ دو می‌باشد. در این راستا مقاومت فشاری و خمشی جهت بررسی رفتار مکانیکی طرح مخلوط‌های مورد مطالعه در سنین مختلف اندازه‌گیری شدند. از سوی دیگر، مقاومت شیمیایی در برابر حملات باران‌های اسیدی شبیه‌سازی شده از طریق بررسی عینی، اندازه‌گیری افت وزنی و مطالعات ریزساختاری از طریق آنالیز سی‌تی‌اسکن و آزمایش SEM صورت گرفت. بر اساس نتایج به دست آمده، افزودن هر دو الیاف مذکور در بتن باعث کاهش مقاومت فشاری در مقایسه با مقدار متناظر در بتن شاهد شد. ولی برعکس افزایش مقاومت خمشی را در پی داشت، که این اثر با افزودن مواد پوزولانی به ‌مراتب چشمگیرتر گردید. با این وجود، بتن معمولی و الیافی حاوی مواد پوزولانی عملکرد منفی‌ای در برابر حملات باران اسیدی از خود نشان دادند. بر اساس نتایج سی‌تی‌اسکن و آنالیز SEM، بتن‌های حاوی مواد پوزولانی دارای ساختار متخلخلی هستند. همچنین به دلیل واکنش‌های آهک‌زدایی ناشی از حملات اسیدی نسبت کلسیم به سیلیسیم در آن‌ها به‌ مراتب کمتر از نمونه شاهد می‌باشد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Investigation of mechanical behavior of fibrous concrete containing pumice and metakaolin and chemical resistance to acid attack

نویسندگان [English]

  • kianoosh samimi 1
  • Mahyar pakan 2
  • amirhossein firoozbakht 3
1 Assistant professor - Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran.
2 PhD student - Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran.
3 Research and Development Service, Imen Rah Consulting Engineering Co., No7, 4th.St Khaled Eslamboli (Vozara) Ave. Tehran, Iran.
چکیده [English]

Using fibers to reduce cracks and increase the joint spacing of concrete slabs has become popular in the concrete pavements of airports and freeways recently. However, their durability behavior against acid rain has been less studied. The purpose of this paper is to investigate the mechanical performance and durability of concrete reinforced with polyolefin and polypropylene fibers containing 15% of pozzolanic materials (pumice or metakaolin) instead of Portland type II cement. In this regard, compressive and flexural strength were measured to investigate the mechanical behavior of the studied mixtures at different ages. On the other hand, chemical resistance against acid rain simulated was investigated through the visual examination and weight loss, and also microstructural analysis was performed by SEM analysis and CT scan testing. Based on these results, the addition of both of these fibers in concrete reduces the compressive strength of concretes compared to the similar content in the control concrete. On the contrary, fibers increased flexural strength, which became much more significant with the addition of pozzolanic materials. However, ordinary and fibrous concrete containing pozzolanic materials showed a weak performance against acid rain. Based on the results of CT scan and SEM analysis, concretes containing pozzolanic materials have a porous structure. Besides, the ratio of calcium to silicon in them is much lower than the control concrete due to decalcification reactions caused by acid attacks.

کلیدواژه‌ها [English]

  • Acid attack
  • CT scan analysis
  • Metakaolin
  • Microstructure
  • Pumice

مراجع

[1] C.X. Qian, P. Stroeven, Development of hybrid polypropylene-steel fibre-reinforced concrete, Cement and Concrete Research, 30(1) (2000) 63-69.
[2] J. Wang, Q. Dai, R. Si, S. Guo, Mechanical, durability, and microstructural properties of macro synthetic polypropylene (PP) fiber-reinforced rubber concrete, Journal of Cleaner Production, 234 (2019) 1351-1364.
[3] A.M. Zeyad, A.H. Khan, B.A. Tayeh, Durability and strength characteristics of high-strength concrete incorporated with volcanic pumice powder and polypropylene fibers, Journal of Materials Research and Technology, 9(1) (2020) 806-818.
[4] S.E. Vakili, P. Homami, M.R. Esfahani, Effect of fibers and hybrid fibers on the shear strength of lightweight concrete beams reinforced with GFRP bars, in, Elsevier, pp. 290-297.
[5] S. Ullah Khan, T. Ayub, Flexure and shear behaviour of self-compacting reinforced concrete beams with polyethylene terephthalate fibres and strips, in, Elsevier, pp. 200-211.
[6] S.M.S. Kazmi, M.J. Munir, Y.-F. Wu, I. Patnaikuni, Y. Zhou, F. Xing, Axial stress-strain behavior of macro-synthetic fiber reinforced recycled aggregate concrete, Cement and Concrete Composites, 97 (2019) 341-356.
[7] K. Samimi, S. Kamali-Bernard, A.A. Maghsoudi, Durability of self-compacting concrete containing pumice and zeolite against acid attack, carbonation and marine environment, Construction and Building Materials, 165 (2018) 247-263.
[8] A.S. Gill, R. Siddique, Durability properties of self-compacting concrete incorporating metakaolin and rice husk ash, Construction and Building Materials, 176 (2018) 323-332.
[9] M. Nematzadeh, S. Fallah-Valukolaee, Erosion resistance of high-strength concrete containing forta-ferro fibers against sulfuric acid attack with an optimum design, Construction and Building Materials, 154 (2017) 675-686.
[10] R. Chen, K. Yang, X. Qiu, X. Zeng, P. Wang, J. Xu, J. Chen, Degradation mechanism of CA mortar in CRTS I slab ballastless railway track in the Southwest acid rain region of China–Materials analysis, Construction and Building Materials, 149 (2017) 921-933.
[11] M.C. Chen, K. Wang, L. Xie, Deterioration mechanism of cementitious materials under acid rain attack, Engineering Failure Analysis, 27 (2013) 272-285.
[12] X. Hu, Y. Guo, J. Lv, J. Mao, The Mechanical Properties and Chloride Resistance of Concrete Reinforced with Hybrid Polypropylene and Basalt Fibres, Materials, 12(15) (2019) 2371-2371.
[13] R. San Nicolas, M. Cyr, G. Escadeillas, Performance-based approach to durability of concrete containing flash-calcined metakaolin as cement replacement, Construction and Building Materials, 55 (2014) 313-322.
[14] P. Dinakar, P.K. Sahoo, G. Sriram, Effect of Metakaolin Content on the Properties of High Strength Concrete, International Journal of Concrete Structures and Materials, 7(3) (2013) 215-223.
[15] K. Samimi, S. Kamali-Bernard, A.A. Maghsoudi, M. Maghsoudi, H. Siad, Influence of pumice and zeolite on compressive strength, transport properties and resistance to chloride penetration of high strength self-compacting concretes, Construction and building materials, 151 (2017) 292-311.
[16] K. Samimi, Contribution à l'étude de la durabilité des BAP dans les milieux agressifs: effets des pouzzolanes naturelles,  (2016).
[17] A. Ramezanianpour, M. Samadian, M. Mahdikhani, Engineering properties and durability of selfconsolidating concretes (SCC) containing volcanic pumice ASH,  (2012).
[18] H.A. Khan, A. Castel, M.S.H. Khan, A.H. Mahmood, Durability of calcium aluminate and sulphate resistant Portland cement based mortars in aggressive sewer environment and sulphuric acid, Cement and Concrete Research, 124 (2019) 105852-105852.
[19] I.G. Richardson, G.W. Groves, Microstructure and microanalysis of hardened ordinary Portland cement pastes, Journal of Materials Science, 28(1) (1993) 265-277.
[20] M. Koushkbaghi, M.J. Kazemi, H. Mosavi, E. Mohseni, Acid resistance and durability properties of steel fiber-reinforced concrete incorporating rice husk ash and recycled aggregate, Construction and Building Materials, 202 (2019) 266-275.
[21] H. Cardenas, K. Kupwade-Patil, S. Eklund, Recovery from Sulfate Attack in Concrete via Electrokinetic Nanoparticle Treatment, Journal of Materials in Civil Engineering, 23(7) (2011) 1103-1112.
[22] M.-C. Chen, K. Wang, L. Xie, Deterioration mechanism of cementitious materials under acid rain attack, Engineering Failure Analysis, 27 (2013) 272-285.
[23] J. Monteny, E. Vincke, A. Beeldens, N. De Belie, L. Taerwe, D. Van Gemert, W. Verstraete, Chemical, microbiological, and in situ test methods for biogenic sulfuric acid corrosion of concrete, Cement and Concrete Research, 30(4) (2000) 623-634.
[24] Y.-f. FAN, H.-y. LUAN, Pore structure in concrete exposed to acid deposit, Construction and Building Materials, 49 (2013) 407-416.
[25] Ł. Skarżyński, J. Tejchman, Experimental investigations of fracture process in concrete by means of X-ray micro-computed tomography, Strain, 52(1) (2016) 26-45.
نشریه مهندسی عمران امیرکبیر
دوره 54، شماره 6
شهریور 1401
صفحه 2395-2414

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