مطالعه تأثیر نوع و مقدار پوزولان بر چسبندگی بتن خودتراکم سبک حاوی لیکا با استفاده از روش پوش اوت

نوع مقاله : مقاله پژوهشی

نویسندگان

گروه مهندسی عمران، واحد قزوین، دانشگاه آزاد اسلامی، قزوین، ایران

چکیده

امروزه استفاده از بتن سبک سازه ای به منظور سبک سازی سازه ها که منجر به عملکرد مناسب تر در برابر زلزله می گردد بسیار مورد توجه قرار گرفته است. لذا به کارگیری بتن خودتراکم سبک که هم نیاز به تراکم ندارد و می تواند تمامی فضای قالب را پر کند و هم وزن کمتر، در ترمیم و مرمت سازه ها گزینه ای منطقی و مناسب است. در این پژوهش 16 طرح مخلوط بتن خودتراکم سبک به کار گرفته شده است. از پنج پوزولان متاکائولن، سرباره، خاکستر بادی، خاکستر پوسته برنج و زئولیت به میزان 5، 5/7 و 10 درصد وزنی سیمان و سبکدانه لیکا در مخلوط ها استفاده شده است. مدول الاستیسیته، جمع شدگی، مقاومت فشاری و مقاومت کششی برای تعیین ویژگی های مکانیکی، روش پوش اوت برای تعیین چسبندگی و آزمون های جریان اسلامپ، قیف V، جعبه L و T50 برای تعیین ویژگی های رئولوژیکی مخلوط ها مورد ارزیابی قرار گرفته اند. نتایج نشان دادند که بیشترین افزایش چسبندگی مربوط به نمونه حاوی دارای 5 درصد متاکائولن (با حدود 68 درصد افزایش نسبت به نمونه بدون پوزولان) و بیشترین کاهش مربوط به نمونه دارای 10 درصد زئولیت می باشد (با حدود 13 درصد کاهش نسبت به نمونه بدون پوزولان). همچنبن بهترین ویژگی های رئولوژیکی با افزودن متاکائولن و ضعیف ترین آن با افزودن زئولیت به دست آمده است. افزودن پوزولان ها در تمامی موارد باعث افزایش ویژگی های مکانیکی مخلوط ها شد.

کلیدواژه‌ها

عنوان مقاله [English]

Studying the Effect of Various Pozzolans in Different Percentages on the Bond Strength of Lightweight Self-compacting Concrete

نویسندگان [English]

  • Seyed Mahdi Mousavi
  • Ali Delnavaz
  • Seyed Amir HOSSEIN Hashemi
Department of civil engineering, Qazvin branch, Islamic Azad University, Qazvin, Iran
چکیده [English]

One of the most suitable materials for using in construction is self-compacting concrete. This type of concrete, not only due to the lack of the need for vibration but also because of lesser weight resulting from using lightweight aggregate instead of gravel, could be a proper option to be utilized in earthquake-prone areas. Especially in cases where the existing structure, including the building, needs to be retrofitted and repaired, the presence of lightweight concrete with no need to compaction can be auspicious. Thus, in this study, 32 mix designs of self-compacting concrete were used as research. In these mix designs, the type of lightweight aggregate, both type and amount of pozzolan were changed to evaluate the effect of each one on the bond strength properties of concrete. The concretes were placed in acidic environments, and then the bond strength was assessed using push-out and splitting-prism methods. From the results, it is shown that pozzolan containing 5% of metakaolin and 10% of zeolite has the best and worst rheological properties, respectively. The rate of reduction and changes in the bond strength in sulfuric acid are lower than those of hydrochloric acid. Specimens containing scoria show higher bond strength values. Furthermore, by exposure to acidic environments, after 7 days the specimens containing scoria and after passing 28 and 60 days, the specimens containing lica experienced the least reduction of bond strength

کلیدواژه‌ها [English]

  • Lightweight Self-compacting Concrete
  • Bond Strength
  • Various Pozzolans

مراجع

[1] Dawei Zhang, Tamon Ueda, Hitoshi Furuuchi, (2011), “Avereage crack spacing of overlay-strengthened RC beams”, Journal of materials in civil engineering, ASCE, October .
[2] N. Banthia, R. Gupta, S. Mindess, (2006), “Development of fiber reinforced concrete repair materials”, Can. J. Civ. Eng., 33, 126-133
[3] Y. Theiner, G. Hofstetter, (2012), “Evaluation of the effects of drying shrinkage on the behavior of concrete structures strengthened by overlays”, Cem. and Conc. Res., 42, 1286-1297
[4] Laurence, O., Bissonnette, B., Pigeon, M., and Rossi, P., (2000), “Effect of steel macro fibres on cracking of thin concrete repairs". In Proceedings, 5th International RILEM Symposium on FibreReinforced Concretes (BEFIB 2000), Lyon, France, pp. 213–222.
[5] Naderi, M., Ghodousian, O., (2010), “Assessing the Adhesion of Self-Compacting Concrete and Mortar Applied to Different Concrete surfaces, using twist-off and Friction-Transfer Methods, and its Estimation By Fuzzy Logic”, Journal of Civil Engineering, Ferdowsi Mashhad, Vol 23 NO 1.[ In Persian]
[6] Pedro Miguel Duarte Santos and Eduardo Nuno Brito Santos Júlio., (2011), "Factors Affecting Bond between New and Old Concrete" ACI Materials Journal/July-August .
[7] W.Hansen, J.A. Almudaiheem, (1987), “Ultimate drying shrinkage of concrete – influence of major parameters”, ACI Mater. J., 84, 217-223
[8] O. Challal, B. Benmokrane, G. Ballavy, (1992), “Drying shrinkage strains: experimental versus codes, ACI Mater. J., 89, 263-266
[9] ACI committee 209, (1982), “Pridiction of creep, Shrinkage and temperature effects in concrete structures, designing for creep and shrinkage in concrete structures”, SP-76, American concrete institute, Detroit, 193-300
[10] Euro-Internatioinale du beton, (1978), “Model code for concrete structures”, Paris.
[11] B. Bissonnette, P. Pierre, M. Pigeon, (1999), “ Influence of key parameters on drying shrinkage of cementitious materials”, cement and concrete research, 29, 1655-1662
[12] V. Baroghel-Bouny, M. Mainguy, T. Lassabatere, O. Coussy, (1999), “Characterization and identification of equilibrium and transfer moisture properties for ordinary and high-performance cementitious materials”, Cement and concrete research, 29, 1225-1238
[13] Tianxiong Guo, Yuchen Xie, Xingzhong Weng, (2018) “Evaluation of the bond strength of a novel concrete for rapid patch repair of pavements”, Construction and Building Materials, 186 ,790–800.
[14] F. Ascione, M. Lamberti, A. Napoli, A.G. Razaqpur , R. Realfonzo, (2019), “Modeling SRP-concrete interfacial bond behavior and strength”, Engineering Structures 187 , 220–230.
[15] Luc Courard , Tomasz Piotrowski, Andrzej Garbacz, (2014), “Near-to-surface properties affecting bond strength in concrete repair”, Cement & Concrete Composites 46 ,  73–80.
[16] Bing Wang, Shilang Xu , Fei Liu , (2016), “Evaluation of tensile bonding strength between UHTCC repair materials and concrete substrate”, Construction and Building Materials 112 , 595–606.
[17] S.H. Abo Sabah, M.H. Hassan, N. Muhamad Bunnori, M.A. Megat Johari , (2019) , “Bond strength of the interface between normal concrete substrate and GUSMRC repair material overlay” , Construction and Building Materials 216 ,  261–271.
[18] ASTM C33, (2005),  Srandard Specification for Concrete Aggregates.
[19] ASTM C330, (2004), “Standard specification for lightweight aggregates for structural concrete”, Annual Book of ASTM Standards, Volume 04.02;.
[20] EFNARC, “The European guidelines for self-compacting concrete, specification, production and use”, May 2005.

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