اثر اندازه آزمونه بر مقاومت فشاری، کششی و خمشی بتن‌های حاوی الیاف فولادی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 کارشناس ارشد مهندسی سازه، گروه مهندسی عمران، واحد سمنان، دانشگاه آزاد اسلامی، سمنان، ایران

2 دانشیار، گروه مهندسی عمران، واحد سمنان، دانشگاه آزاد اسلامی، سمنان، ایران

چکیده

استفاده از الیاف در بتن سبب کاهش قابل‌توجه تردی و شکنندگی بتن شده و بتن حاصله از همگنی بالایی برخوردار خواهد بود. در این تحقیق 160 نمونه بتن الیافی شامل 64 نمونه مکعبی برای آزمایش مقاومت فشاری، 64 نمونه استوانه‌ای برای آزمایشات مقاومت فشاری و کششی و 32 نمونه تیر برای آزمایش مقاومت خمشی مورد آزمایش و بررسی قرار گرفتند. همچنین در این پژوهش 4 رده‌ی بتن مورد آزمایش قرار گرفتند که از هر رده بتن و هر ابعاد 4 نمونه ساخته شد که 1 نمونه بدون الیاف (به عنوان نمونه مبنا) و 3 نمونه با الیاف فولادی دو انتها قلاب (5/0درصد حجم بتن مصرفی) بود. نتایج نشان داد که مقاومت خمشی، کششی و فشاری بتن با حضور الیاف افزایش یافته و ضرایب تبدیل مقاومت جدیدی برای نمونه‌های حاوی الیاف ارائه گردید.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

The Effect of Specimen size on Compressive, Tensile and Flexural Strength of Steel Fiber Reinforced Concrete

نویسندگان [English]

  • Arman Ebrahimian 1
  • Alireza Mortezaei 2
1 M.Sc. of Structural Engineering, Civil Engineering Department, Semnan Branch, Islamic Azad University, Semnan, Iran
2 Associate Professor, Seismic Geotechnical and High Performance Concrete Research Centre, Civil Engineering Department, Semnan Branch, Islamic Azad University, Semnan, Iran
چکیده [English]

The use of fiber in concrete has increased dramatically over the last few decades. The use of fiber in concrete causes the concrete to become ductile to a considerable extent. In this study, 160 samples of fiber concrete containing 64 cube samples with dimensions of 5×5×5, 10×10×10, 15×15×15, 20×20×20 cm for testing of compressive strength, 64 cylindrical cylinders with dimensions (diameter × height) of 15 × 30 and 10 × 20 cm for compressive strength and tensile strength tests and 32 samples of beam with dimensions of 10×45×10 and 15×60 ×15 were used for flexural strength testing. Furthermore, in this study, 4 concrete strength ranges of 20MPa, 25MPa, 30MPa and 35MPa were tested. Of each concrete grade and each dimension, four samples were made; one of which was non-fibrous (as the original sample) and three samples with fibers. The steel fibers used were two-end hooks of 3.5 cm in length and 0.8 mm in thickness, with 0.5% of the volume of concrete used. The results showed that the flexural, tensile and compressive strength of concrete increased to about 35% in the presence of fibers, and new strength conversion coefficients were introduced for fiber-containing samples. The conversion coefficients of compressive strength of fibrous cubic specimens increased by 15% compared to the coefficients presented in Section 9 of the National Building Regulations, which is due to presence of fibers in concrete

کلیدواژه‌ها [English]

  • Size effect
  • steel fiber
  • compression strength
  • tensile strength
  • flexural strength
  • conversion factor

مراجع

 
[1] M. Di Prisco, G. Plizzari, L. Vandewalle, "Fibre reinforced concrete: new design perspectives." Materials and Structures 42 (9) (2009): 1261–1281.
[2] M.G. Alberti, A. Enfedaque, J.C. Gálvez, "Fibre reinforced concrete with a combination of polyolefin and steel-hooked fibres." Composite Structures 171 (2017) 317–325.
[3] Chen, Hui, Wei-Jian Yi, and Zhongguo John Ma. "Shear size effect in simply supported RC deep beams." Engineering Structures 182 (2019): 268-278.
[4] Fládr, Josef, and Petr Bílý. "Specimen size effect on compressive and flexural strength of high-strength fibre-reinforced concrete containing coarse aggregate." Composites Part B: Engineering 138 (2018): 77-86.
[5] Gortsas, Theodore V., Stephanos V. Tsinopoulos, Dimitrios Rodopoulos, and Demosthenes Polyzos. "Strain gradient elasticity and size effects in the bending of fiber composite plates." International Journal of Solids and Structures 143 (2018): 103-112.
[6] Xie, Yongping, Zhenbao Li, Lei Jia, Hongyu Zhou, Wenting Bai, and Yuan Li. "Flexural behavior and size effect of normal-strength RC columns under monotonic horizontal loading." Engineering Structures 166 (2018): 251-262.
 [7] Li, M., Hao, H., Shi, Y. and Hao, Y., "Specimen shape and size effects on the concrete compressive strength under static and dynamic tests." Construction and Building Materials 161 (2018): 84-93.
[8] Nouali, Abdelhafid, and Mohammed Matallah. "A simplified approach to assess the size effect on the shear-flexure interaction in RC elements." Engineering Structures 144 (2017): 151-162.
[9] Jin, Liu, Xiuli Du, Dong Li, and Xiao Su. "Seismic behavior of RC cantilever beams under low cyclic loading and size effect on shear strength: An experimental characterization." Engineering Structures 122 (2016): 93-107.
[10] Wang, D. Y., Z. Y. Wang, Scott T. Smith, and Tao Yu. "Size effect on axial stress-strain behavior of CFRP-confined square concrete columns." Construction and Building Materials 118 (2016): 116-126.
[11] Sobhani Kavkani H.R., Mortezaei A., Naghizadeh R. 2016. The effect of metakaolin, silica fume and nanosilica on the mechanical properties and microstructure of cement mortar, Iranian Journal of Materials Science and Engineering, 13(2): 50-61.
[12] Bažant ZP. Size effect. International Journal of Solids and Structures 3 (2000): 69–80.
[13] Bažant ZP. Size effect on structural strength: a review. Archive of Applied Mechanics 69 (1999): 703–25.
[14] Gonnermann HF. Effect of size and shape if test specimen on compressive strength of concrete. Proc ASTM 1925; 25(2):237–50.
[15] The Concrete Society: http://www.concrete.org.uk/fingertips-print.asp?docid=918.
[16] Xincheng P. Super-high-strength high performance concrete. Boca Raton, Florida, USA: CRC Press (2013).
[17] Zhang H. Building materials in civil engineering. Sawston, UK: Woodhead Publishing Limited (2011).
[18] Graybeal B, Davis M. Cylinder and cube: strength testing of 80 to 200 MPa (11.6 to 29 ksi) ultra-high-performance fiber-reinforced concrete. ACI Material Journal November-December (2008): 603–609.
[19] An M, Zhang L, Yi Q. Size effect on compressive strength of reactive powder concrete. Journal of China University of Mining and Technology 18 (2008): 279–82.
[20] Dehestani M, Nikbin IM, Asadollahi S. Effects of specimen shape and size on the compressive strength of self-consolidating concrete (SCC). Construction and Building Materials 66 (2014): 685–691.
[21] Del Viso JR, Carmona JR, Ruiz G. Shape and size effects on the compressive strength of high-strength concrete. Cement and Concrete Research 38 (2008): 386–395.
[22] Yi S-T, Yang E-I, Choi J-C. Effect of specimen sizes, specimen shapes, and placement directions on compressive strength of concrete. Nuclear Engineering and Design 23 (2006): 115–127.
[23] Tokyay M, Özdemir M. Specimen shape and size effect on the compressive strength of higher strength concrete. Cement and Concrete Research 27 (1997): 1281–1289.
[24] Zabihi N, Eren Ö. Compressive strength conversion factors of concrete as affected by specimen shape and size. Research Journal of Applied Sciences, Engineering and Technology 7 (2014): 4251–4257.
[25] Fládr, Josef, and Petr Bílý. "Specimen size effect on compressive and flexural strength of high-strength fibre-reinforced concrete containing coarse aggregate." Composites Part B: Engineering 138 (2018): 77-86.
 [26] Shirin Jafari, mohammadtaghi ahmadi. Effect of Tensile Strength Considering Size Effect and Loading Rate on Optimum Design of Arch Dam. Sharif Journal, 10.24200/J30.2018.1899.2001.
[27] Khaloo, A., Molaei Raisi, E., Hosseini, P., Tahsiri, H. Mechanical performance of self-compacting concrete reinforced with steel fibers, Construction and Building Materials, 51 (2014): 179-186,
[28] Khaloo, A., Afshari, M. Flexural behaviour of small steel fibre reinforced concrete slabs. Cement and concrete composites, 27(1), 2005: 141-149.
 

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سابقه مقاله

  • تاریخ دریافت: 17 اسفند 1399
  • تاریخ بازنگری: 20 بهمن 1400
  • تاریخ پذیرش: 16 تیر 1400

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