بررسی تاثیر پودر مگنتیت (اکسید آهن) بر خواص مکانیکی بتن خود تراکم

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری دانشگاه صنعتی شاهرود

2 دانشیار، دانشگاه صنعتی شاهرود

3 استاد، دانشگاه صنعتی شاهرود

4 مدیر تحقیق و توسعه شرکت آپتوس ایران

5 کارشناس ارشد تحقیق و توسعه شرکت آپتوس ایران

چکیده

بتن خود تراکم، بتنی است که بدون اعمال هیچگونه انرژی خارجی و تحت اثر وزن خود متراکم می‌گردد. این بتن کـه ماده ای بسیـار سیال و روان و مخلوطی همگن است، بررسی اثر موادمعدنی بر خصوصیات فیزیکی و مکانیکی بتن خود تراکم به عنوان یکی از موارد با اهمیت در سال های اخیر مورد مطالعه قرار گرفته شده است. از آنجایی که کشور ایران دارای مناطق فراوانی از ذخایر عظیم سنگ آهن است، بنابراین در این تحقیق خصوصیات فیزیکی، مکانیکی و خصوصیات شکست بتن خود تراکم حاوی مگنتیت مورد مطالعه قرار گرفت. در این مطالعه از ذرات مگنتیت با اندازه 0 تا 2 میلی متر به میزان 2، 5 و 10 درصد وزنی سیمان به منظور بررسی خصوصیات مکانیکی، فیزیکی،نحوه و پارامترهای موثر بر شکست بتن خود تراکم استفاده شد. آزمایش‌های مقاومت فشاری ، مقاومت کششی، مقاومت خمشی و سرعت انتشار امواج اولتراسونیک برای بررسی خصوصیات مکانیکی نمونه‌ها مورد استفاده قرار گرفت. نتایج نشان ‌داد که با افزایش درصد مگنتیت، خصوصیات مکانیکی و فیزیکی بتن خود تراکم در سنین پایین کاهش می‌یابد ولی با افزایش سن نمونه ها این خصوصیات جبران خواهد شد. همچنین خصوصیات مکانیکی نمونه‌ها در مقدار 2 درصد تفاوت چندانی با نمونه‌های شاهد فاقد مگنتیت نشان نمی‌داد. در بررسی خصوصیات شکست بتن خود تراکم مشخص شد که با افزایش درصد مگنتیت شکست‌های فرادانه‌ای کاهش و شکست‌های بین‌دانه‌ای و درون‌دانه‌ای به دلیل کاهش چسبندگی سیمان و دانه‌های مصالح و موجب افزایش تخلخل و به دنبال آن سبب کاهش جذب آب می شود.

کلیدواژه‌ها


عنوان مقاله [English]

Investigation of the effect of magnetite (iron oxide) on the mechanical properties of self-compacting concrete

نویسندگان [English]

  • Hosein Inanloo arabi shad 1
  • Farhang Sereshki 2
  • Mohammad Ataei 3
  • Saeed Bozorgmehr 4
  • Leila Akbari nasab 5
1 PhD Condidate, Shahrood University of technology
2 Associate Professor, Shahrood University of technology
3 Professor, Shahrood University of technology
4 R&D Manager of Aptus Iran Company
5 R&D Expert of Aptus Iran Company
چکیده [English]

Self-compacting concrete is a concrete that compresses without applying any external energy under its own weight. This concrete, which is a very fluid and fluid mixture, has been studied in recent years to study the effect of minerals on the physical and mechanical properties of self-compacting concrete.Since the country has vast areas of large reserves of iron ore, so in this study, the physical, mechanical and concrete properties of self-compacting magnetite density were studied.In this study, 2, 5 and 10 wt% cement magnetite particles with size 0 to 2 mm were used to determine the mechanical, physical, behavioral and effective parameters of self-compacting concrete. The compressive strength tests, tensile strength, flexural strength and ultrasonic emission velocity were used to study the mechanical properties of the samples.The results showed that with increasing magnetite percentage, the mechanical and physical properties of self-compacting concrete decreased in the early ages, but with the age of the samples, these properties would be compensated. Also, the mechanical properties of the specimens in the 2% difference were not significantly different with the control samples without magnetite.In studying the properties of self-compacting concrete, it was determined that with increasing magnetite percentage, the loss of metadata fractures and the loss of biodiversity and inundations due to reduced adhesion of cement and aggregates and increased porosity and subsequently reduced water absorption.

کلیدواژه‌ها [English]

  • Magnetite
  • mechanical properties of self-compacting concrete
  • fracture properties
[1]American Concrete Institute,(2007), ACI 237-R-07, Self-Consolidating Concrete,.

[2]Okamura H., Ozawa K. ,( June 25, 1995), Mix Design for Self-Compacting Concrete, Concrete Library of  Japanese Society of Civil Engineers, p. 107-120.

[3] Bartos,P.J.M and Grauers, M. (1999) ,Self- Compacting Concrete, Concrete, ol.33,No.4,pp9-,.

[4]LiH, Xiao H, Yuan J, Ou J. (2004), Microstructure of cement mortar with nano-particles, Composites, Part B 35 ,pp. 185–189.

[5]Li H, Zhang M, Ou J (2006). Abrasion resistance of concrete containing nano-particles for pavement. Wear. 260: 1262–1266.

[6]Nazari A, Riahi Sh (2011) TiO2 nanoparticles effects on physical, thermal and mechanical properties of selfcompacting concrete with ground granulated blast furnace slag as binder, Energy and Buildings 43: 995–1002.

[7]Riahi Sh, Nazari A (2011) Physical, mechanical and thermal properties of concrete in different curingmedia containing ZnO2 nanoparticles. Energy and Buildings 43: 1977–1984.

[8]Åkesson, U., Hansson, J. & Stigh, J. (2004). Characterisation of microcracks in the Bohus granite, western Sweden, caused by uniaxial cyclic loading. Engineering Geology, 72(1-2), 131–142. http://doi.org/10.1016/j.enggeo.2003.07.001.

[9]Takemura T, Golshani A, Oda M, Suzuki K (2003) Preferred orientations of openmicrocracks in granite and their relation with anisotropic elasticity.. International Journal of Rock Mechanics & Mining Sciences, 2003, 40(4):443–454.

[10]Liu S, Faisal Anwar AHM, Cheol Kim B, Ichikawa Y (2006) Observation of microcracks in granite using a confocal laser scanning microscope. Int J Rock Mech Min Sci 43(8):1293-1305. doi:10.1016/j.ijrmms.2006.04.006.

[11]Kumano, A and Goldsmith, (1982), An analytical and experimental investigation of the effect of impact on coarse granular rocks, Rock Mechanics, vol. 15, 67–97.

[12]Schild, M, Vollbrecht, A, Siegesmund, S & Reutel, (1998), Microcracks in granite cores from theEPS-1 geothermal drill hole, Soultz-sous-Foreö ts (France): paleostress directions, paleofluid sand crack-related Vp-anisotropies, Geol Rundsh., vol. 86, pp 775-785.

[13]Schild, M, Siegesmund, S, Vollbrecht, A & Mazurek, (M 2001), Characterization of granite matrixporosity and pore-space geometry by in situ and laboratory methods, Geophysic JournalInternational, vol. 146, pp 111-125.

[14]Machek, M, Špaček, P, Ulrich, S & Heidelbach, (F 2007), Origin and orientation of microporosity ineclogites of different microstructure studied by ultrasound and microfabric analysis,Engineering Geology, vol 89, 266-277.

[15] Omar, H, Irfah Mohd Pauzi, N, Abu-Shariah, M, Yusof, Z & Maail, ( 2009), Microcracks patternand the degree of weathering in granite, The Electronic Journal of GeotechnicalEngineering, vol. 14, Bundle B.

[16]Brace, ( 1977), Permeability from resistivity and pore shape. Journal of Geophysical Research, vol. 82, pp 3343-3349.

[17]Kranz R. (1983) ,Microcracks in rocks: A review, Tectonophsysics, 100, pp 449-480.

[18]Jern M (2002) Micro and macro crack growth as a result of blasting. In: Proceedings of the 7th International Symposium on Rock Fragmentation by Blasting. Beijing, China, August 11-15, pp 155-161.

[19]Griffith, AA ,(1924), Theory of rupture, Proceedings of the International Congress Applied

Mechanics, Delft, Netherlands, pp 55–63.

[20] ASTM C33, (2005), Standard Specification for  Leightweight Aggregates for Structural Concrete,.

[21]Morgan JW, Anders E ,(1980) ,Chemical composition of Earth, Venus, and Mercury. Proc Natl Acad Sci USA 77(12):6973-6977. doi:10.1073/pnas.77.12.6973.

[22]Ohmoto H, (2003) ,Nonredox transformations of magnetite-hematite in hydrothermal systems. Econ Geol 98:299-304.

[23]Clout J M F, Manuel J R, (2015), Iron Ore: Mineralogy, Processing and Environmental Sustainability. Woodhead,Elsevier Ltd,.

[24]Waychunas G A, (1991), Crystal chemistry of oxides and oxyhydroxides. Reviews in Mineralogy and Geochemistry, 25:11–68.

[25]ASTM C39, (2003), Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens,.

[26]ASTM C496, (2004),Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete

Specimens,.

[27]ASTM C78,(2002 ) , Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading).

[28]ASTM C597, (2003), Standard Test Method forPulse Velocity Through Concrete.

[29]Balaguru,P.N.,and Ramakrishnan,V.(1986).Freeze thaw durability of fiber reinforced concrete,ACI Journal Proceedings,83(3), 374-382.

 [30]Hoseini,M., Bindiganavile, V., and Banathia, N.(2009). The effect of mechanical stress on permeability of concrete: A review, Cement and Concrete Composites,31(4),213-220.