اعتبار،چابکی،پاسخگویی

بررسی تأثیر شاخص خمیری بنتونیت بر مدول الاستیسیته، مقاومت فشاری و کارایی بتن پلاستیک

نوع مقاله : مقاله پژوهشی

نویسندگان

1 عضو هیات علمی و استادیار گروه عمران، دانشکده فنی و مهدسی، دانشگاه آزاد اسلامی، واحد شبستر، شبستر، ایران

2 کارشناسی ارشد عمران-مهندسی سازه، واحد شبستر، دانشگاه آزاد اسلامی، شبستر، ایران

چکیده
بتن پلاستیک در چهار دهۀ گذشته به منظور استفاده در سازه‌های آب‌بند، به طور موفقیت آمیزی در کنترل تراش مورد استفاده قرار گرفته است. بتن پلاستیک از ترکیب، سیمان، بنتونیت، مصالح سنگی و آب تشکیل می‌شود. از نظر مصالح تشکیل دهنده، تفاوت بتن پلاستیک با بتن معمولی، وجود بنتونیت و نسبت بالای آب به سیمان در آن است. این دو عامل باعث می‌شوند که بتن پلاستیک در ضمن دارا بودن خاصیت خمیری، مقاومت فشاری و مدول الاستیسیته بسیار کمتری نسبت به بتن‌های معمولی داشته و بنابراین انعطاف پذیر باشد. بنتونیت یکی از مهمترین مواد تشکیل دهنده در بتن پلاستیک است که موجب پرشدن حفرات و فضای خالی بتن می‌شود. بتن پلاستیک به عنوان مادۀ مناسب برای دیوارهای آب‌بند سد مورد استفاده در سدها شناخته می‌شود. در زمینه اثر بنتونیت در بتن پلاستیک، در دنیا و بویژه در ایران تحقیقات جامعی انجام نشده و بیشتر کارهای صورت گرفته، بررسی‌های موردی مرتبط با پروژه‌های انجام شده است. بدین منظور، برای ساخت بتن پلاستیک بهینه‌تر نیاز است تا اثرات تغییرات مشخصات بنتونیت و بویژه اثر تغییر نشانۀ خمیری آن مورد ارزیابی قرار گیرد و با توجه به اینکه در کشورمان تحقیقات گسترده‌ای در این زمینه صورت نگرفته است، لذا در این تحقیق سعی شده است تا گامی در این جهت برداشته شود. به همین منظور، پس از انجام آزمایش‌ها و بررسی‌های مقدماتی و در نهایت انجام آزمایش‌هایی بر روی 51 طرح مختلف و تعیین مقاومت فشاری، مدول الاستیسیته و کارایی آنها، منحنی‌های استخراج شد. بر اساس نتایج بدست آمده، با افزایش مقدار نشانۀ خمیری بنتونیت مقاومت فشاری، مدول الاستیسیته و روانی بتن کاهش می‌یابد.

کلیدواژه‌ها

عنوان مقاله English

Investigation of the effect of bentonite paste index on modulus of elasticity, compressive strength and performance of plastic concrete

نویسندگان English

farhad pirmohammadi alishah 1
Navid Mahmoudzadeh 2
1 Faculty Member and Assistant Professor, Department of Civil Engineering, Faculty of Engineering and Engineering, Islamic Azad University, Shabestar Branch, Shabestar, Iran
2 Master of Civil Engineering-Structural Engineering, Shabestar Branch, Islamic Azad University, Shabestar, Iran
چکیده English

Plastic concrete have been used for some four decades in watertight structures. In these four decades, plastic concrete has been successfully used in engineering control projects for seepage. Plastic concrete is produced by mixing of cement, bentonite, aggregates and water. Presence of bentonite and high water-cement ratio is difference between plastic concrete and conventional concrete. These two factor cause plastic concrete, besides possession of water tighting property, have a very lesser comperssive strength and modulus of elasticity in comparsion with conventional concrete and therefore be more deformable. Researches that fulfilled on this type of concrete in the word and especially in Iran, were not extensive and most of done works have been typical studies on relative projects. In order to make more economical plastic concrete, it is necessary to evaluate the effects of changes in the properties of bentonite, and in particular the effect of its plastic index change, and given that there is no extensive research in this field in our country, we try to move toward this goal in this these. Therefore after primary stduies and test, 51 mix designs were teseted and compressive strength, modulus of elasticity and workability of them were determined. Based on the results, with increasing amount of plastic index of bentonite, compressive strength, elasticity modulus and workability decrease.

کلیدواژه‌ها English

  • Plastic concrete
  • Bentonite
  • Dough mark
  • Compressive strength
  • Modulus of elasticity
[1] Noorpur M, Karbati Asl R, Zandi. 2011. Investigation of the effect of natural pozzolan (Sahand tuff) on the properties
of plastic concrete. Sixth National Congress of Civil Engineering, Semnan University, Semnan, May 6 and 7, pp: 1-8.
[2] Liu J.P., L. Li, C.W. Miao, Q. Tian, Q.P. Ran and Y.J. Wang, 2011. Reduction of water evaporation and cracks on
plastic concrete surface by monolayers. Colloids Surf. A Physicochem. Eng. Asp., 384(1-3): 496-500.
[3] Hinchberger S., J. Weck and T. Newson, 2010. Mechanical and hydraulic characterization of plastic concrete for
seepage cut-off walls. Can. Geotech. J., 47(4), pp: 461-471.
[4] Afshin H, Yathribi S, Sadeghi Dodran R. 2005. The effect of pozzolanic additives on the properties of plastic concrete,
2nd National Congress of Civil Engineering, Tehran, University of Science and Technology.
[5] Afsharnejad M., Olipour M., alias M. 2012. Modification of clay properties for use in dam sealing walls. 9th
International Congress of Civil Engineering, Isfahan University of Technology, pp: 1-6.
www.cpjournals.com ISSN:6262-155X )Civil & Project Journal)CPJ(( پروژه و عمران نشریه
ػاَ دْٚ، دٚسٜ 2 ،ؿٕاسٜ 5ٔ ،شداد 1399،ؿٕاسٜ پ٥اپ٣ 15،کفحٝ 87 تا کفحٝ 109
997
[6] Soroush M., Mujtahid A.F. 2012. General design and implementation of plastic concrete sealing walls behind dams.
Proceedings of a workshop and specialized workshop on specific issues of dam design and related organizations, Isfahan
University of Technology, Isfahan.
[7] Secretary A. 2014. Laboratory study of the effect of bentonite content on compressive strength, elastic modulus and
permeability of plastic concrete, 15th Conference of Civil Engineering Students, 11, 12, 13 September, Urmia University.
[8] Bagheri, A. R. Alibabaie, M. Babaie, M. 2008. Reduction in the permeability of plastic concrete for cut-off walls
through utilization of silica fume, Construction and Building Materials, 22 (6), pp 1247-1252.
[9] Imitation of the famous M., Pourbagheri H. 2013. Application of plastic concrete in sealing the foundations of earth
dams. The First National Conference on Geotechnical Engineering of Iran, Faculty of Engineering, Mohaghegh Ardabili
University, October 20, 2010.
[10] Mohajeri of Qala-e-R Tower, Ajam A. 2012 Investigation of the effect of water to cement ratio on the permeability of
plastic concretes in dam wall sealing, Second National Conference on New Findings in Civil Engineering, Abad, 15 and 16
Azar, Islamic Azad University, Najaf Branch.
[11] Bagheri, A. R. Alibabaie, M. Babaie, M. 2008. Reduction in the permeability of plastic concrete for cut-off.
Construction and Building Materials 22 (2008), pp:1247–1252
[12] Kazemian S,، Ghareh S، Torkanloo N. 2016. To Investigation of Plastic Concrete Bentonite Changes on It`s Physical
Properties. international confrerence on sustainable design ،engineering construction. Procedia Engineering 145.1080 –
1087
[13] Abbaslou H, Ghanizade A.R, Tavana A. 2016. The compatibility of bentonite/sepiolite plastic concrete cut-off wall
material. Construction and Building Materials, 124)15(, pp: 1165–1173
[14] Kazemian S, Ghareh S. 2017. Effects of Cement, Different Bentonite, and Aggregates on Plastic Concrete in BeshGhardash Dam, Iran. Journal of Testing and Evaluation, Volume 45, Issue 1, pp: 242-248.
[15] Scientific-research journal, 2018. "Mining Engineering", Volume 4, Number 7, pp: 1-4-42
[16] National Committee of Great Dams of Iran. 1997. Filler materials for creating sealing walls. Publications of the
National Committee of Great Dams of Iran.
[17] ASTM D4318-17e1, 2017. Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils,
ASTM International, West Conshohocken, PA.
[18] ASTM C939 / C939M-16a, 2016. Standard Test Method for Flow of Grout for Preplaced-Aggregate Concrete (Flow
Cone Method), ASTM International, West Conshohocken, PA.
[19] ASTM C143 / C143M-20, 2020. Standard Test Method for Slump of Hydraulic-Cement Concrete, ASTM
International, West Conshohocken, PA.
[20] ASTM D3148-02, 2002. Standard Test Method for Elastic Moduli of Intact Rock Core Specimens in Uniaxial
Compression (Withdrawn 2005), ASTM International, West Conshohocken, PA.
www.cpjournals.com ISSN:6262-155X )Civil & Project Journal)CPJ(( پروژه و عمران نشریه
ػاَ دْٚ، دٚسٜ 2 ،ؿٕاسٜ 5ٔ ،شداد 1399،ؿٕاسٜ پ٥اپ٣ 15،کفحٝ 87 تا کفحٝ 109
998
[21] ASTM C469 / C469M-14, 2014.Standard Test Method for Static Modulus of Elasticity and Poisson’s Ratio of
Concrete in Compression, ASTM International, West Conshohocken, PA.
[22] ASTM C617 / C617M-15, 2015. Standard Practice for Capping Cylindrical Concrete Specimens, ASTM
International, West Conshohocken, PA, 2015.
[23] Islamian F. 2005. Geomatic properties of plastic concrete wall sealing of Karkheh dam, 4th dam construction
conference, Tehran Esfand.
[24] Sedghiani M.H., Soodkhah M. 2001. Investigation of mechanical behavior of plastic concrete mixing designs of
Karkheh dam sealing wall and its optimization based on design needs. First International Concrete and Development
Conference, Tehran, May.
[25] Khaloo, A., 1997. Effective parameters in the behavior of plastic concrete, the first seminar on earth and gravel dams,
Tehran, October.
[26] Coduto D. Geotechnical Engneering, 2010. Principles & Practices (2nd Edition), Publisher: Pearson; 2nd edition, 794.
  • تاریخ دریافت 21 تیر 1399
  • تاریخ بازنگری 21 مرداد 1399
  • تاریخ پذیرش 28 مرداد 1399
  • تاریخ اولین انتشار 28 مرداد 1399
  • تاریخ انتشار 01 مرداد 1399