پیوندهای مفید
آمار
| تعداد نشریات | 8 |
| تعداد شمارهها | 438 |
| تعداد مقالات | 5,652 |
| تعداد مشاهده مقاله | 7,693,740 |
| تعداد دریافت فایل اصل مقاله | 6,343,950 |
بررسی آزمایشگاهی پارامترهای شکست تیر بتنی ساخته شده از ماده مرکب سیمانی مهندسی شده | ||
| نشریه مهندسی عمران امیرکبیر | ||
| مقاله 23، دوره 54، شماره 8، آبان 1401، صفحه 2877-2894 اصل مقاله (2.33 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22060/ceej.2022.19326.7140 | ||
| نویسندگان | ||
| سید مهدی امیرفخریان؛ محمدرضا اصفهانی* | ||
| دانشکده مهندسی، دانشگاه فردوسی مشهد، مشهد، ایران | ||
| چکیده | ||
| وجود ترک در سازههای بتنی سبب می شود که در بسیاری از موارد معیارهای متداول قادر به پیشبینی صحیح شکست آنها نباشند. با بهره گیری از علم مکانیک شکست و معیارهای موجود آن میتوان رفتار شکست اینگونه سازه ها را به درستی پیش بینی کرد. در این پژوهش آزمایشگاهی با استفاده از روش های مکانیک شکست، پارامترهای شکست تیر خمشی ساخته شده از ماده مرکب سیمانی مهندسی شده (ECC) مورد بررسی قرار می گیرد. 6 نمونه تیر آزمایشگاهی شکافدار با ابعاد 100×100×350 میلیمتر مکعب بر اساس روش کار شکست (WFM) و 18 نمونه تیر آزمایشگاهی شکافدار با ابعاد 70×70×190، 70×140×380 و 70×280×760 میلیمتر مکعب بر اساس روش اثر اندازه بازانت (SEM) ساخته و آزمایش شدند. مواد مورد استفاده برای تهیه ECC شامل الیاف پلیپروپیلن، سیمان، غبار کوره آهن، میکروسیلیس و پودر سنگ بودند. از دو نسبت الیاف (1 و 2 درصد) در مخلوط های مختلف استفاده شد. مشاهده شد که با افزایش الیاف از 1 درصد به 2 درصد مقدار مقاومت خمشی، انرژی شکست در روش WFM(GF)، انرژی شکست در روش SEM (Gf) و چقرمگی شکست (KIC) نمونه ها افزایش مییابند. از طرف دیگر، مقاومت فشاری، طول مشخصه (Lch) و عدد تردی نمونه ها با افزایش الیاف کاهش می یابند. همچنین قانون اثر اندازه بازانت در نمونه های مختلف ساخته شده از ECC مورد بحث و بررسی قرار گرفت. | ||
| کلیدواژهها | ||
| ماده مرکب سیمانی مهندسی شده (ECC)؛ انرژی شکست؛ چقرمگی؛ کار شکست (WFM)؛ اثر اندازه بازانت (SEM) | ||
| موضوعات | ||
| مکانیک شکست | ||
| عنوان مقاله [English] | ||
| An Experimental Investigation on Fracture Parameters of Concrete Beams Made of Engineered Cementitious Composites (ECC) | ||
| نویسندگان [English] | ||
| Seyed Mahdi Amirfakhrian؛ M. R. Esfahani | ||
| Faculty of Engineering, Ferdowsi University of Mashhad | ||
| چکیده [English] | ||
| Due to the existence of cracks in concrete structures, the conventional strength criteria may not be able to predict their failure. It has been shown that the theories of fracture mechanics can predict the behavior of these structures appropriately. In this experimental and analytical study, by using fracture mechanics theories, fracture parameters of flexural different specimens made of Engineered Cementitious Composites (ECC) are investigated. 24 flexural specimens with the notch at their mid-length were manufactured and tested. Six of these specimens with the dimensions of 350×100×100 mm were conducted under Work of Fracture Method (WFM) and other 18 specimens with the dimensions of 190×70×70 mm3, 380×140×70 mm3 and 760×280×70 mm3 were studied under Size Effect Method (SEM). The materials used for ECC included polypropylene fibers, cement, iron furnace slag, silica fume and stone powder. Two ratios of fibers (1% and 2%) were used in different mixtures of ECC. It was observed that by increasing fibers from 1% to 2%, the amount of flexural strength, fracture energy and fracture toughness (KIC) of the specimens increased. On the other hand, compressive strength, characteristic length (Lch) and brittleness number of specimens decreased. The Bažant’s size effect law was also discussed for the ECC specimens. | ||
| کلیدواژهها [English] | ||
| Engineered Cementitious Composite (ECC), Fracture Energy, Toughness, Work of Fracture Method (WFM), Size Effect Method (SEM) | ||
| مراجع | ||
|
[1] S. Wang, Micromechanics based matrix design for engineered cementitious composites, University of Michigan, (2005). [2] A. Kawamata, H. Mihashi, Y. Kaneko, K. Kirikoshi, Controlling fracture toughness of matrix for ductile fiber reinforced cementitious composites, Engineering fracture mechanics, 69(2) (2002) 249-265. [3] J. Zhang, C.K. Leung, Y.N. Cheung, Flexural performance of layered ECC-concrete composite beam, Composites science and technology, 66(11-12) (2006) 1501-1512. [4] V.C. Li, Engineered cementitious composites (ECC) material, structural, and durability performance, in: Concrete Construction Engineering Handbook, CRC Press, (2008). [5] V.C. Li, Integrated structures and materials design, Materials and Structures, 40(4) (2007) 387-396. [6] W. Liu, S. Xu, Q. Li, Experimental study on fracture performance of ultra-high toughness cementitious composites with J-integral, Engineering Fracture Mechanics, 96 (2012) 656-666. [7] V.C. Li, Large volume, high‐performance applications of fibers in civil engineering, Journal of Applied Polymer Science, 83(3) (2002) 660-686. [8] V.C. Li, On engineered cementitious composites (ECC), Journal of advanced concrete technology, 1(3) (2003) 215-230. [9] V.C. Li, S. Wang, Microstructure variability and macroscopic composite properties of high performance fiber reinforced cementitious composites, Probabilistic Engineering Mechanics, 21(3) (2006) 201-206. [10] V.C. Li, T. Hashida, Engineering ductile fracture in brittle-matrix composites, Journal of Materials Science Letters, 12(12) (1993) 898-901. [11] V.C. Li, H. Horii, P. Kabele, T. Kanda, Y. Lim, Repair and retrofit with engineered cementitious composites, Engineering Fracture Mechanics, 65(2-3) (2000) 317-334. [12] S. Xu, Y. Zhu, Experimental determination of fracture parameters for crack propagation in hardening cement paste and mortar, International Journal of Fracture, 157(1-2) (2009) 33-43. [13] S.P. Shah, S.E. Swartz, C. Ouyang, Fracture mechanics of concrete: applications of fracture mechanics to concrete, rock and other quasi-brittle materials, John Wiley & Sons, 1995. [14] A. Hillerborg, M. Modéer, P.-E. Petersson, Analysis of crack formation and crack growth in concrete by means of fracture mechanics and finite elements, Cement and concrete research, 6(6) (1976) 773-781. [15] Z.P. Bažant, B.H. Oh, Crack band theory for fracture of concrete, Material and construction, 16(3) (1983) 155-177. [16] Y. Jenq, S. Shah, A fracture toughness criterion for concrete, Engineering Fracture Mechanics, 21(5) (1985) 1055-1069. [17] Y. Jenq, S.P. Shah, Two parameter fracture model for concrete, Journal of engineering mechanics, 111(10) (1985) 1227-1241. [18] Z. Bažant, M. Kazemi, Determination of fracture energy, process zone longth and brittleness number from size effect, with application to rock and conerete, International Journal of fracture, 44(2) (1990) 111-131. [19] M.F. Marji, Numerical analysis of quasi-static crack branching in brittle solids by a modified displacement discontinuity method, International Journal of Solids and Structures, 51(9) (2014) 1716-1736. [20] RILEM 50-FMC, Determination of the fracture energy of mortar and concrete by means of three-point bend tests on notched beams, Materials and structures, 18(106) (1985) 285-290. [21] RILEM Technical Committee 89-FMT, Size-Effect Method for Determining Fracture Energy and Process Zone Size of Concrete, Materials and Structures, 23(6) (1990) 461-465. [22] A. Hillerborg, The theoretical basis of a method to determine the fracture energyGF of concrete, Materials and structures, 18(4) (1985) 291-296. [23] Z.P. Bažant, P.A. Pfeiffer, Determination of fracture energy from size effect and brittleness number, ACI Materials Journal, 84(6) (1987) 463-480. [24] Q. Yu, J.-L. Le, C.G. Hoover, Z.P. Bažant, Problems with Hu-Duan boundary effect model and its comparison to size-shape effect law for quasi-brittle fracture, Journal of engineering mechanics, 136(1) (2010) 40-50. [25] C.G. Hoover, Z.P. Bažant, Comparison of the Hu-Duan boundary effect model with the size-shape effect law for quasi-brittle fracture based on new comprehensive fracture tests, Journal of Engineering Mechanics, 140(3) (2014) 480-486. [26] ASTM C 1609/C 1609M -07. Standard Test Method for Flexural Performance of Fiber Reinforced Concrete (Using Beam with Third-Point Loading), in, ASTM International, West Conshohoken, PA, (2008). [27] BS EN 12390-3. Testing hardened concrete - Part 3: Compressive strength of test specimens, in: Incorporating corrigendum, (2011). [28] ASTM C 78-08. Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading, in, ASTM International, West Conshohocken, PA, (2008). [29] ASTM 496/C 496M -04. Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens, in, ASTM International, West Conshohocken, PA, (2004). [30] ASTM C 39/C 39M – 03. Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens, in, ASTM International, West Conshohocken, PA, (2005). [31] Y. Murakami, L. Keer, Stress intensity factors handbook, vol. 3, (1993). [32] J. Roesler, G. Paulino, C. Gaedicke, A. Bordelon, K. Park, Fracture behavior of functionally graded concrete materials for rigid pavements, Transportation Research Record, 2037(1) (2007) 40-49. [33] E. Güneyisi, M. Gesoglu, T. Özturan, S. İpek, Fracture behavior and mechanical properties of concrete with artificial lightweight aggregate and steel fiber, Construction and Building Materials, 84 (2015) 156-168. [34] M. Ghasemi, M.R. Ghasemi, S.R. Mousavi, Investigating the effects of maximum aggregate size on self-compacting steel fiber reinforced concrete fracture parameters, Construction and Building Materials, 162 (2018) 674-682. [35] Z.P. Bažant, E. Becq-Giraudon, Statistical prediction of fracture parameters of concrete and implications for choice of testing standard, Cement and concrete research, 32(4) (2002) 529-556. [36] J. Planas, M. Elices, G. Guinea, Measurement of the fracture energy using three-point bend tests: Part 2—Influence of bulk energy dissipation, Materials and Structures, 25(5) (1992) 305-312. [37] R.A. Einsfeld, M.S. Velasco, Fracture parameters for high-performance concrete, Cement and Concrete Research, 36(3) (2006) 576-583. | ||
|
آمار تعداد مشاهده مقاله: 839 تعداد دریافت فایل اصل مقاله: 1,075 |
||