اثر ریزساختار فیزیکی منافذ بر مقاومت فشاری و جذب آب در بتن‌های خودتراکم حاوی میکروسیلیس و متاکائولین

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشگاه علم و صنعت ایران

2 دانشکده مهندسی عمران، واحد نجف آباد، دانشگاه آزاد اسلامی، نجف آباد، ایران

چکیده

شناخت ریزساختار فیزیکی از جمله توزیع اندازه منافذ و نفوذپذیری بتن در مقابل آب به دلیل اثر آن بر دوام بلند مدت، حائز اهمیت است. هدف تحقیق حاضر بررسی اثر ریزساختار فیزیکی منافذ در بتن‌های خودتراکم حاوی متاکائولین و میکروسیلیس بر درصد جذب آب و جذب مویینه آب و مقاومت فشاری است. بتن‌‌های خودتراکم با مقدار مواد سیمانی kg/m3450 و نسبت آب به سیمان 35/0، 45/0 و 55/0 طراحی شدند. ترکیب‌های دوتایی و سه تایی سیمان، میکروسیلیس و متاکائولین برای این تحقیق ساخته شد. به منظور بررسی تفاوت اثر متاکائولین و میکروسیلیس بر ریزساختار فیزیکی، مخلوط‌های حاوی متاکائولین و جایگزینی میکروسیلیس و متاکائولین با نسبت آب به سیمان 0.45 ساخته شد. مشخصات ریزساختار فیزیکی شامل اندازه میانه منافذ، حجم منافذ بزرگ و کوچک مویینه در بتن‌های خودتراکم پوزولانی توسط آزمایش تخلخل‌سنجی جیوه‌ای اندازه گیری شد. آزمایش‌های مقاومت فشاری، جذب حجمی و مویینه آب بر روی نمونه‌های بتن خودتراکم انجام شد. نتایج نشان داد که عامل موثر مهم بر مقاومت فشاری و نفوذ‌پذیری در برابر آب، اندازه میانه منافذ و حجم منافذ بزرگ مویینه است. بتن حاوی 20 درصد متاکائولین و 8 درصد میکروسیلیس علیرغم داشتن بیشترین مقاومت فشاری 77 مگاپاسکال، کمترین تخلخل را نداشت. کمترین تخلخل با مقدار 6/8 درصد، متعلق به بتن خودتراکم حاوی میکروسیلیس و نسبت آب به سیمان 35/0 است.

کلیدواژه‌ها

عنوان مقاله [English]

The effect of the pores physical microstructure on water transport and compressive strength in self-compacting concretes containing silica fume and metakaolin

نویسندگان [English]

  • parviz ghoddousi 1
  • leyla Adelzade Saadabadi 2
1 iran university of science and technology
2 Department of Civil Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
چکیده [English]

Understanding the physical microstructure, including pores size distribution and water absorption of concrete, because of its effect on long-term durability is important. The aim of the present study is to investigate the effect of physical microstructure of pozzolanic self-compacting concretes on compressive strength and water permeability. Self-compacting concrete mixes were designed with total cementitious material content of 450 kg/m3 with water to cementitious material ratio of 0.35, 0.45 and 0.55. The binary and ternary blends of cement, silica fume and metakaolin were used for the purpose of present study. In order to investigate the difference between the effect of metakaolin and silica fume on the physical microstructure, mixtures containing binary and ternary blends of cement, silica fume and metakaolin with water to cement ratio of 0.45 were considered. Pore physical microstructure characteristics including median pore size, volume of large and small capillary pore in self-compacting concretes were investigated. Pore size distribution of self-compacting concrete samples were measured by mercury porosity test. The compressive strength, water absorption and capillary water sorptivity were performed on samples. The results showed that an important effective factor on compressive strength and water permeability is the medium size of the pores and the volume of large capillary pores. The concrete containing 20% metakaolin and 8% silica fume did not have the lowest porosity despite having the highest compressive strength. The lowest porosity with 8.6% belongs to self-compacting concrete containing silica fume with water to cement ratio of 0.35.

کلیدواژه‌ها [English]

  • pores physical micro-structure
  • self-compacting concrete
  • metakaolin
  • silica fume
  • water absorption

مراجع

[1] Ghoddousi. P, Parhizkar. T, Ramezanianpour, A.A, and Mozaffari. N, "Concrete technology in the invironmental conditions of persion gulf(Vol.2): in persian". tehran: Building and Housing Research Center, 2004.
[2] Atahan. H. N, Oktar O.N, and Tas. M. A, “Effects of water – cement ratio and curing time on the critical pore width of hardened cement paste,” Construction and Building Materials, vol. 23, no. 3, pp. 1196–1200, 2009.
[3] Mindess.S , Young .J. F, and Darwin.D, "concrete". Prentice Hall, 2003.
[4] Chen .X and Wu.S, “Influence of water-to-cement ratio and curing period on pore structure of cement mortar,” Construction and Building Materials, vol. 38, pp. 804–812, 2013.
[5] Zhao .H, Xiao. Q, Huang.D, and Zhang.S, “Influence of Pore Structure on Compressive Strength of Cement Mortar,” , The Scientific World Journal , Hindawi Publishing Corporation , 2014.
[6] Bentur, A, “The pore structure of hydrated cementitious compounds of different chemical composition,” Journal of the American Ceramic Society, vol. 63, no. 7‐8, pp. 381–386, 1980.
[7] Okpala.D.C, “Pore structure of hardened cement paste and mortar,” International Journal of Cement Composites and Lightweight Concrete, vol. 11, no. 4, pp. 245–254, 1989.
[8] Poon.C.S, Lam.L , Kou.S, Wong.Y.L , and Wong.R, “Rate of pozzolanic reaction of metakaolin in high-performance cement pastes,” Cement and Concrete Research, vol. 31, no. 9, pp. 1301–1306, Sep. 2001.
[9] Nežerka.V , Bílý.P , Hrbek. V, and Fládr.J, “Impact of silica fume, fly ash, and metakaolin on the thickness and strength of the ITZ in concrete,” Cement and Concrete Composites, vol. 103, pp. 252–262, 2019.
[10] Qin.Z, Ma.C , Zheng.Z , Long.G , and Chen.B, “Effects of metakaolin on properties and microstructure of magnesium phosphate cement,” Construction and Building Materials, vol. 234, p. 117353, 2020.
[11] Li .Y, Chen. Y, Wei. J, He. X, Zhang. H, and Zhang . W, “A study on the relationship between porosity of the cement paste with mineral additives and compressive strength of mortar based on this paste,” Cement and Concrete Research, vol. 36, no. 9, pp. 1740–1743, 2006.
[12] Bartonic .E, Kuzielová. E, and Matúš. Z, “The correlation between porosity and mechanical properties of multicomponent systems consisting of Portland cement – slag – silica fume – metakaolin ˇ emlic,” Construction and Building Materials, vol. 135, pp. 306–314, 2017.
[13] Khatib. J. M and Wild .S, “Pore size distribution of metakaolin paste,” Cement and Concrete Research, vol. 26, no. 10, pp. 1545–1553, 1996.
[14] Frı́as. M and Cabrera. J, “Pore size distribution and degree of hydration of metakaolin–cement pastes,” Cement and Concrete Research, vol. 30, no. 4, pp. 561–569, 2000.
[15] Ambroise .J, Maximilien. S, and Pera .J, “Properties of metakaolin blended cements,” Advanced Cement Based Materials, vol. 1, no. 4, pp. 161–168, 1994.
[16] Cwirzen.A and  Penttala.V, “Aggregate–cement paste transition zone properties affecting the salt–frost damage of high-performance concretes,” Cement and Concrete Research, vol. 35, no. 4, pp. 671–679, 2005.
[17] Diamond.S, “A critical comparison of mercury porosimetry and capillary condensation pore size distributions of portland cement pastes,” Cement and concrete research, vol. 1, no. 5, pp. 531–545, 1971.
[18] Odler.I  and Rößler.M, “Investigations on the relationship between porosity, structure and strength of hydrated Portland cement pastes. II. Effect of pore structure and of degree of hydration,” Cement and Concrete Research, vol. 15, no. 3, pp. 401–410, 1985.
[19] chiller.K.K, “Strength of porous materials,” Cement and Concrete Research, vol. 1, no. 4, pp. 419–422, 1971.
[20] Chen.X,  Wu.S, andZhou.J, “Influence of porosity on compressive and tensile strength of cement mortar,” vol. 40, pp. 869–874, 2013.
[21] Lian.C, Zhuge.Y, and Beecham.S, “The relationship between porosity and strength for porous concrete,” Construction and Building Materials, vol. 25, no. 11, pp. 4294–4298, 2011.
[22] El .A and  Georges.S, “Porosity of self-compacting concrete,” Procedia Engineering, vol. 123, pp. 145–152, 2015.
[23] Assié.S, Escadeillas.G, and Waller.V, “Estimates of self-compacting concrete ‘potential’ durability,” Construction and Building Materials, vol. 21, no. 10, pp. 1909–1917, 2007.
[24]  Tjaronge.M.W and Ria.U, “Porosity , pore size and compressive strength of self compacting concrete using sea water,” Procedia Engineering, vol. 125, pp. 832–837, 2015.
[25] Kumar.R and Bhattacharjee.B, “Porosity , pore size distribution and in situ strength of concrete,” Cement and Concrete Research ,33 vol. 33, pp. 155–164, 2003.
[26] Das.B.B and Kondraivendhan.B, “Implication of pore size distribution parameters on compressive strength , permeability and hydraulic diffusivity of concrete,” Construction and Building Materials, vol. 28, no. 1, pp. 382–386, 2012.
[27] Ollivier .J.P and  Massat.M, “Permeability and microstructure of concrete • a review of modelling,” Cement and Concrete Research,  vol. 22, pp. 503–514, 1992.
[28] Kapoor.K,Singh.S.P , and Singh.B, “Water Permeation Properties of Self Compacting Concrete Made with Coarse and Fine Recycled Concrete Aggregates,” International Journal of Civil Engineering,Vol.16, pp. 47-56, 2018.
[29] Güneyisi.E , Gesoǧlu.M, Karaoǧlu.S, and  Mermerdaş.K, “Strength, permeability and shrinkage cracking of silica fume and metakaolin concretes,” Construction and Building Materials, vol. 34, pp. 120–130, 2012.
[30] Shi.Z, Shui.Z, Li.Q, and Geng.H, “Combined effect of metakaolin and sea water on performance and microstructures of concrete,” Construction and Building Materials, vol. 74, pp. 57–64, Jan. 2015.
[31] . Hassan .A. A. A, M. Lachemi.M, and Hossain. K. M. A, “Effect of metakaolin and silica fume on the durability of self-consolidating concrete,” Cement and Concrete Composites, vol. 34, no. 6, pp. 801–807, 2012.
[32] R. Madandoust.M and S. Y. Mousavi.S.Y, “Fresh and hardened properties of self-compacting concrete containing metakaolin,” Construction and Building Materials, vol. 35, no. 3, pp. 752–760, 2012.
[33] Ramezanianpour.A.A, Pilvar.A,  Mahdikhani.M, and Moodi.F, “Practical evaluation of relationship between concrete resistivity, water penetration, rapid chloride penetration and compressive strength,” Construction and Building Materials, vol. 25, no. 5, pp. 2472–2479, 2011.
[34] Ramezanianpour .A.A and Jovein.H.B, “Influence of metakaolin as supplementary cementing material on strength and durability of concretes,” Construction and Building Materials, vol. 30, pp. 470–479, 2012.
[35] Ghoddousi.G and Parhizkar.T, “The effect of Concrete Quality on Performance of Surface Treatment materials,” in Sustainable construction materials and technologies, 2007, pp. 78–84.
[36] Cam.H.T and Neithalath.N, “Moisture and ionic transport in concretes containing coarse limestone powder,” Cement and Concrete Composites, vol. 32, no. 7, pp. 486–496, Aug. 2010.
[37] European Federation for Specialist Construction Chemicals and Concrete Systems, “EFNARC , Guidelines for self-compacting concrete.” p. 32, 2002.
[38] ilho.J.H,Medeiros .M. H. F, Pereira.E, Helene.P, and Isaia.G.C, “High-Volume Fly Ash Concrete with and without Hydrated Lime: Chloride Diffusion Coefficient from Accelerated Test,” Journal of Materials in Civil Engineering, vol. 25, no. 3, pp. 411–418, 2013.
[39] Duan.P, Shui.Z, Chen.W, and Shen.C, “Efficiency of mineral admixtures in concrete: Microstructure, compressive strength and stability of hydrate phases,” Applied Clay Science, vol. 83–84, pp. 115–121, 2013.
[40] Liu.J, Ou.G,  Qiu.Q,Chen.X, Hong.J, and F. Xing.F, “Chloride transport and microstructure of concrete with / without fly ash under atmospheric chloride condition,” Construction and Building Materials, vol. 146, pp. 493–501, 2017.
[41] Duan.P, Shui.Z, Chen.W, and Shen.C, “E nhancing microstructure and durability of concrete from ground granulated blast furnace slag and metakaolin,” Journal of Materials Research and Technology, vol. 2, no. 1, pp. 52–59, 2013.
[42] Astm C642-97, “Standard Test Method for Density , Absorption , and Voids in Hardened Concrete,” Annual Book of ASTM Standards, no. March, pp. 1–3, 1997.
[43] Popovics.S, Strength and related properties of concrete: A quantitative approach. John wiley & sons, 1998.

فایل ها

هم رسانی

ارجاع به این مقاله

آمار