پیوندهای مفید
آمار
| تعداد نشریات | 8 |
| تعداد شماره‌ها | 417 |
| تعداد مقالات | 5,494 |
| تعداد مشاهده مقاله | 6,135,783 |
| تعداد دریافت فایل اصل مقاله | 5,380,584 |
بررسی اثر افزودنی کاهنده جمع‌شدگی در بتن مورد استفاده در روسازیهای بتنی | ||
| نشریه مهندسی عمران امیرکبیر | ||
| مقاله 12، دوره 53، شماره 7، مهر 1400، صفحه 2921-2936 اصل مقاله (2.28 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22060/ceej.2020.17542.6600 | ||
| نویسندگان | ||
| مسعود غلامی1؛ فریدون مقدس نژاد* 2؛ علی اکبر رمضانیان پور3؛ امیرمحمد رمضانیان پور4 | ||
| 1گروه راه و ترابری، دانشکده مهندسی عمران و محیط زیست، دانشگاه صنعتی امیرکبیر | ||
| 2دانشگاه صنعتی امیر کبیر، تهران، ایران | ||
| 3دانشگاه صنعتی امیرکبیر، تهران، ایران | ||
| 4دانشگاه تهران، تهران، ایران | ||
| چکیده | ||
| کاهش منابع نفتی و طول عمر نه چندان بالای روسازیهای آسفالتی، استفاده از روسازی بتنی را در جهان، مورد توجه قرار داده است. یکی از مشکلات اصلی روسازیهای بتنی، پدیده جمع‌شدگی (مخصوصاً ناشی از خشک شدن) است که در اثر از دست رفتن آب موجود در ساختار بتن ایجاد و سبب ایجاد تنش کششی در سطح المان‌های آن می‌گردد که اگر تنش ایجاد شده از مقاومت کششی بتن بیشتر باشد، ترک‌هایی در سطح بتن پدیدار می‌شود. افزودنی کاهنده جمع‌شدگی از جمله موادی است که به واسطه کاهش کشش سطحی و فشار جداکننده، سبب کاهش تنش کششی ایجاد شده در بتن می‌شود. هدف از انجام این پژوهش، بررسی اثر افزودنی کاهنده جمع‌شدگی بر مشخصات فیزیکی و مکانیکی بتن مورد استفاده در روسازیهای بتنی می‌باشد. آزمایش‌های اسلامپ، مقاومت فشاری، خمشی، الکتریکی، اصطکاک سطحی، جمع‌شدگی‌های آزاد و مقید بر روی بتن شاهد و بتن حاوی ماده کاهنده جمع‌شدگی (2 درصد وزن سیمان) در دو نسبت آب به سیمان 0/35 و 0/4 انجام شد. نتایج نشان‌دهنده آن است که استفاده از ماده کاهنده جمع‌شدگی تأثیر چندانی بر کارایی بتن نگذاشته است. کاربرد این ماده در بتن سبب کاهش حدود 10 درصدی مقاومت فشاری، خمشی و الکتریکی می‌شود. به علاوه این ماده میزان جمع‌شدگی آزاد، مقید و عرض ترک‌های ایجاد شده را به ترتیب حدود 10، 20 و 40 درصد کاهش می‌دهد و سن ترک‌خوردگی را حدود 7 روز به تأخیر می‌اندازد. با این حال تأثیر این افزودنی بر روی اصطکاک سطحی واضح و مشخص نمی‌باشد. | ||
| کلیدواژه‌ها | ||
| روسازی بتنی؛ جمع‌شدگی ناشی از خشک شدن؛ تنشهای کششی؛ ترک در بتن؛ افزودنی کاهنده جمع‌شدگی | ||
| موضوعات | ||
| تکنولوژی بتن؛ راه و ترابری و حمل و نقل - روسازی صلب بتنی | ||
| عنوان مقاله [English] | ||
| The Effect of Shrinkage Reducing Admixture on the Behavior of Concrete used in Concrete Pavements | ||
| نویسندگان [English] | ||
| masood gholami1؛ Fereidoon Moghadas Nejad2؛ Aliakbar Ramezanianpor3؛ Amir mohammad Ramezanianpour4 | ||
| 1highway and transportation engineering, department of civil and environmental engineering, amirkabir university of technology | ||
| 2Dep. of Civil Engineering, Amirkabir University of Technology, tehran, iran | ||
| 3department of civil and environmental engineering, amirkabir university of technology, tehran, iran | ||
| 4Tehran university, tehran, iran | ||
| چکیده [English] | ||
| Concrete pavements are widely used by pavement engineers due to their advantages over flexible pavements such as long lifetime, good performance and durability, etc. However, concrete pavements represent some drawbacks such as shrinkage that increases the tensile stress in concrete, which may lead to cracking, warping, etc. Drying shrinkage is the most important type of shrinkage in concrete pavements. To prevent or reduce the amount of cracking, shrinkage reducing admixture (SRA) can be used. This admixture controls shrinkage by reducing water surface tensile in capillary tubes. In this study, the effect of shrinkage reducing admixture on the behavior of concrete used in concrete pavements was investigated. Slump, compressive strength, third-point flexural strength, electrical resistance, skid resistance, free shrinkage, and restrained shrinkage by ring test were performed. Two water-cement ratios of 0.35 & 0.4 were used for mix design and the percentage of shrinkage reducing admixture used in mixtures was 2% by weight of cement. The results showed that the use of SRA had a negligible effect on workability. Also, the use of SRA caused about a 10% reduction in compressive and flexural strength and electrical resistance. Furthermore, a reduction of 10% and 20% was observed in free and restrained shrinkages, respectively, followed by a 40% reduction in crack width and more than one-week delay in the occurrence of the first crack. Finally, no certain relationship was observed between the usage of SRA and variations of the skid resistance of concrete pavements. | ||
| کلیدواژه‌ها [English] | ||
| Concrete pavement, Drying shrinkage, Tensile stress, Shrinkage cracks, Shrinkage reducing admixture | ||
| مراجع | ||
|
[1] R.A. Embacher, M.B. Snyder, Life-cycle cost comparison of asphalt and concrete pavements on low-volume roads; case study comparisons, Transportation research record, 1749(1) (2001) 28-37. [2] UoS (University of Sheffield), Thin wire reinforcement for concrete, Br Patent Application, No 0130852.7 & 0511012.7 (2005). [3] D. Mostofinejad, Reinforced Concrete Structure, Arkan-e Danesh publication, Volume 1 (2017) (in Persian). [4] Committee of concrete chemical additives, iran concrete Institute, the application of chemical additives in concrete, yazda publication (2014) (in Persian). [5] J. Zhang, V.C. Li, Influences of fibers on drying shrinkage of fiber-reinforced cementitious composite, Journal of engineering mechanics, 127(1) (2001) 37-44. [6] S.H. Kwon, S.P. Shah, Prediction of early-age cracking of fiber-reinforced concrete due to restrained shrinkage, ACI Materials Journal, 105(4) (2008) 381. [7] Y.H. Huang, Pavement Analysis and Design, second ed., Pearson Prentice Hall, 2004. [8] .M. Ruiz, R.O. Rasmussen, G.K. Chang, J.C. Dick, P.K. Nelson, Computer-based guidelines for concrete pavements, volume II: design and construction guidelines and HIPERPAVE II user’s manual, Federal Highway Administration, FHWA–HRT–04–122 (2005). [9] C.J. Lee, D.A. Lange, Y.S. Liu, Prediction of moisture curling of concrete slab, Materials and structures, 44(4) (2011) 787-803. [10] Y. Jane Jiang, S.D. Tayabji, Mechanistic evaluation of test data from long-term pavement performance jointed plain concrete pavement test sections, Transportation research record, 1629(1) (1998) 32-40. [11] P.K. Mehta, P.J. Monteiro, Concrete microstructure, properties and materials, third ed., McGraw-Hill, 2017. [12] M.J. Rosen, J.T. Kunjappu, Surfactants and Interfacial Phenomena, John Wiley & Sons, Inc., Hoboken, New Jersey, (2012). [13] L. Maia, H. Figueiras, S. Nunes, M. Azenha, J. Figueiras, Influence of shrinkage reducing admixtures on distinct SCC mix compositions, Construction and Building Materials, 35 (2012) 304-312. [14] J. Mora-Ruacho, R. Gettu, A. Aguado, Influence of shrinkage-reducing admixtures on the reduction of plastic shrinkage cracking in concrete, Cement and Concrete Research, 39(3) (2009) 141-146. [15] .J. Lee, Y.Y. Kim, Durability of latex modified concrete mixed with a shrinkage reducing agent for bridge deck pavement, International Journal of Concrete Structures and Materials, 12(1) (2018) 23. [16] T. Deboodt, T. Fu, J.H. Ideker, Evaluation of FLWA and SRAs on autogenous deformation and long-term drying shrinkage of high performance concrete, Construction and Building Materials, 119 (2016) 53-60. [17] Y. Wehbe, A. Ghahremaninezhad, Combined effect of shrinkage reducing admixtures (SRA) and superabsorbent polymers (SAP) on the autogenous shrinkage, hydration and properties of cementitious materials, Construction and Building Materials, 138 (2017) 151-162. [18] W. Zuo, P. Feng, P. Zhong, Q. Tian, J. Liu, W. She, Effects of a novel polymer-type shrinkage-reducing admixture on early age microstructure evolution and transport properties of cement pastes, Cement and Concrete Composites, 95 (2019) 33-41. [19] C. Qiao, W. Ni, J. Weiss, Transport due to diffusion, drying, and wicking in concrete containing a shrinkage-reducing admixture, Journal of Materials in Civil Engineering, 29(9) (2017) 04017146. [20] B. Hatami, A.M. Ramezanianpour, A.S. Daryan, Investigation on the Effect of Shrinkage Reducing Admixtures on Shrinkage and Durability of High-Performance Concrete, Journal of Testing and Evaluation, 46(1) (2017) 141-150. [21] A. Bagheri, A. Jamali, M. Pourmir, H. Zanganeh, The Influence of Curing Time on Restrained Shrinkage Cracking of Concrete with Shrinkage Reducing Admixture, Advances in Civil Engineering Materials, 8(1) (2019) 596-610. [22] S. Chen, H. Zhao, Y. Chen, D. Huang, Y. Chen, X. Chen, Experimental study on interior relative humidity development in early-age concrete mixed with shrinkage-reducing and expansive admixtures, Construction and Building Materials, 232 (2020) 117204. [23] Building and housing research center, The national Method for concrete mix design, BHRC Publication, No. S-479 (2008) (in Persian). [24] ISIRI 3206, Concrete-Determination of compressive strength of test specimens, Institute of standards and Industrial research of Iran (1992) (in Persian). [25] ASTM C293, Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Center-Point Loading), ASTM international, (2016). [26] FM5-578, Florida Method of Test for Concrete Resistivity as an Electrical Indicator of its Permeability, Florida Department of Transportation, (2004). [27] BS-EN 13036-4, Road and airfield surface characteristics. Test methods. Method for measurement of slip/skid resistance of a surface: The pendulum test, Slovak: Povrchové vlastnosti vozoviek. Skúšobné metódy. Časť, 4, (2011). [28] ASTM C157, Standard Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete, ASTM international, (2014). [29] ASTM C1581, Standard Test Method for Determining Age at Cracking and Induced Tensile Stress Characteristics of Mortar and Concrete under Restrained Shrinkage, ASTM international, (2016). [30] J. Saliba, E. Rozière, F. Grondin, A. Loukili, Influence of shrinkage-reducing admixtures on plastic and long-term shrinkage, Cement and Concrete Composites, 33(2) (2011) 209-217. [31] P. Lura, B. Pease, G.B. Mazzotta, F. Rajabipour, J. Weiss, Influence of shrinkage-reducing admixtures on development of plastic shrinkage cracks, ACI materials journal, 104(2) (2007) 187. [32] T.F. Yuan, S.K. Kim, K.T. Koh, Y.S. Yoon, Synergistic benefits of using expansive and shrinkage reducing admixture on high-performance concrete, Materials, 11(12) (2018) 2514. | ||
|
آمار تعداد مشاهده مقاله: 958 تعداد دریافت فایل اصل مقاله: 1,096 |
||