بررسی خیز دال‌های بتنی تقویت شده با استفاده از صفحات و میلگردهای پلیمری GFRP وCFRP

نوع مقاله : مقاله پژوهشی

نویسنده

گروه مهندسی عمران، موسسه آموزش عالی مولانا، قزوین، ایران

چکیده

امروزه افزایش انعطاف‌پذیری و مقاوم‌سازی سازه‌ها در برابر انفجار، برخورد و ضربه، یکی از اصلی‌ترین دغدغه‌های سازمان‌های دولتی در سراسر دنیا است. توجه به موضوع خرابی پیش رونده در سال‌های اخیر، باعث پررنگ شدن اهمیت مقاوم‌سازی سازه‌ها در برابر بارهای ناگهانی مانند انفجار شده است. این در حالی است که اکثر سازه‌های موجود، مقاومت و شکل‌پذیری کافی در برابر انفجار و برخورد و ضربه را ندارند. در این پژوهش برای به‌دست آوردن تغییر مکان دال‌ها، رفتار یک دال بتن مسلح یک طرفه در چهار حالت تقویت نشده و تقویت شده با استفاده از صفحات پلیمری از نوع GFRP در سامانه باربر ثقلی ساختمان از رو و زیر دال تحت بار انفجار تماسی به‌صورت یک سازه یک طبقه با یک دهانه در برابر فشار مستقیم ماده منفجره مورد بررسی قرار گرفته است. مدل‌سازی در این پژوهش با خرج انفجاری از جنس TNT و به شکل مکعبی به مقدار 5/0کیلوگرم جهت ارزیابی خیز دال ها با استفاده از نرم افزار اجزاء محدود ANSYS که قابلیت تحلیل سازه تحت بار انفجاری را دارا می‌باشد، انجام گرفته است. شاخص های بارگذاری به‌دست آمده با مدل‌سازی هندسی و دیگر شاخص‌های مورد نیاز سازه در نرم‌افزار به‌صورت ساخت اشیاء سه بعدی کامپیوتری از نرم‌افزار می‌باشد. به‌طور خلاصه نتایج این تحقیق نشان می‌دهد که استفاده از ورق‌های تقویت GFRP و CFRP در کاهش مقدار جابه‌جایی دال بر اثر نیروی حاصل از انفجار، جلوگیری از قلوه‌کنی و فروریزش آوار در دال‌ها موثر بوده و موجب کاهش 62 درصدی تغییر مکان دال خواهد شد. همچنین با افزایش ضخامت دال‌ها و قطر میلگردهای GFRP و تعداد لایه‌های CFRP و درصد پوشش آن بر دال‌ها، خیزی که توسط نمونه‌ها تجربه شده است، به شدت کاهش یافته است.

کلیدواژه‌ها


عنوان مقاله [English]

Investigating the Deflection of Concrete Slabs Reinforced with CFRP and GFRP Plates and Bars

نویسنده [English]

  • S. N. Mirhashemi
چکیده [English]

Today, increasing the flexibility and strength of structures against explosions and impacts is one of the main concerns of governmental organizations across the world. The consideration of progressive destruction has added to the importance of structural strength against explosions and impacts in recent years. In this regard, most of the existing structures do not have adequate resistance and flexibility against explosions and impacts. The present study investigates the behavior of a one-sided concrete slab in four cases, including the reinforced and non-reinforced concrete, using glass-fiber-reinforced plastic (GFRP) plates in a gravity bearing building system on and under the slab explosive-loaded as a one-story structure with a span against direct explosive pressure. A TNT explosion model in the form of a 0.5-kg cube was applied to evaluate the deflection of the slabs in the ANSYS software which is capable of analyzing the explosion-load behavior of the structure. The loading parameters obtained from geometric modeling and other parameters required by the structure were modeled as 3D objects. The results indicated that the use of GFRP and carbon fiber reinforced polymer (CFRP) reinforcement plates were effective in reducing the displacement of the slabs due to the explosion load. They prevented the spalling and collapse of slabs and reduced slab displacement by 62%. In addition, an increase in the thickness of slabs, the diameter of GFRP bars, the number of CFRP layers, and their slab coverage percentage dramatically reduced the deflection of the samples.

کلیدواژه‌ها [English]

  • Explosion
  • Concrete Slab
  • Reinforcement
  • Ansys Autodyn Software
[1]     Road, “Housing and Urban Development Research Center, Department of Rules and Regulations Compilation,” Iranian National Building Code 21: Passive Defense, 1398. (In Persian)##
 [2]     U. S. Army, U. S. Navy, and U. S. A. Force, “DoD Minimum Antiterrorism Standards For Buildings,” U. S. Army Corps of Engineers, 2018.##
[3]     A. Vatani Oskouei, “Concrete Structure, reinforced with FRP rebar,” Tehran, Shahid Rajaee Teacher Training University, 2017. (In Persian)##
[4]     S. Kalavagunta, S. Naganathan, and K. N. Bin Mustapha, “Proposal for Design Rules of Axially Loaded CFRP Strengthened Cold Formed Lipped Channel Steel Sections,” J.  Th-Wall. Stru., vol. 72, pp. 14-19, Spring, 2013.##
[5]     A.‎ M.‎ El-Nemr, ‎“Serviceability of Concrete Members Reinforced with FRP Bars,” Ph.D. Dissertation, Sherbrooke University of Technology, Canada, pp. 1-36, 2013.##
[6]     A. Arabzadeh, A. Amani Dashlejeh, and I. Mahmoudzadeh Kani, “Experimental Study of Prestressed RC Deep Beams Retrofitted by CFRP,” IQBQ, vol. 115, pp. 117-126, 2015.##
[7]     M. Bazli, H. Ashrafi, and A.Vatani Oskouei, “Experiments and Probabilistic Models of Bond Strength Between GFRP Bar and Different Types of Concrete Under Aggressive Environments,” Constr. Build. Mater., vol. 148, pp. 429-443, 2017.##
[8]     A. S. Khshain, M. Alyaa, A. M. Riadh, and S. Jay, “A state-of-the-art review: Near-surface mounted FRP composites for reinforced concrete structures,” Constr. Build. Mater., vol. 209, pp. 748-769, 2019.##
[9]     H. Lamb, “Hydrodynamics,” Cambridge University Press, Cambridge Press, 2010.##
[10] P. A. Buchan and J. F. Chen, “Blast Resistance of FRP Composits and Polymer Strengthened Concrete and Masonary Structures-A State-of-the-Art Review,” J. Comp., vol. 38, pp. 509-522, 2007.##
[11]  G. Abhiroop and A. Satadru Das, “Retrofitting Materials for Enhanced Blast Performance of Structures: Recent advancement and challenges ahead,” Constr. Build. Mater., vol. 204, pp. 224-243, 2019.##
[12] M. Moarefzadeh, “Reliability Analysis of Reinforced Concrete Slabs Subjected to Blast Loads and their Economic Assessment,” Advanced Defense Sci. & Tech., vol. 9(4), pp. 379-392, 1397. (In Persian)##
[13]  Z. Xin, D. Xiuli, C. Zhen, and Z. Fanna, “Possible Collapse Mode for Slender Reinforced Concrete Plates Subjected to Blast Load,” J. Mech. Eng., pp. 500-510, 2008.##
[14]  M. J. Karimloo, M. R. Sohrabi, and M. Ajdari Moghaddam, “An investigation of Concrete Dalle in Chain Conditions and Their Hardening by FRP Fibers,” Passive Defense Quarterly, vol. 2(3), pp. 1-7, 1389. (In Persian)##
[15] A. Esmaeili, S. Sh. Emamzadeh, and M. Aamini Mazrea No, “The Study of CFRP Sheet Arrangement in Reinforcing Unarmed Masonry Walls Against Blast Load,” Passive Defense Quarterly, vol. 5 (4), pp. 1-7, 1393. (In Persian)##
[16] M. Gordan and M. E. Nia omran, “Numerical Evaluation of the Retrofit Effectiveness for Fiber Reinforced Polymers (FRPS) Retrofitted Concrete Slab Subjected to Blast Loading,” IQBQ, vol. 15, pp. 19-30, 1394. (In Persian)##
[17] S. Yao, D. Zhang, X. Chen, F. Lu, and W. Wang, “Experimental and numerical study on the dynamic response of RC slabs under blast loading,” Eng. Fail. Anal., vol. 66, pp. 120-129, 2016.##
[18] K. Nasserasadi, A. tajvar, and J. moradlou, “Analytical Study of Reinforced Concrete Slabs with Ferrocement Under Blast Load,” IQBQ, vol. 18(1), pp. 31-42, 1397. (In Persian)##
[19]  H. Gokkaya and M. Karatasa, “A Review on Machinability of Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP) Composite Materials,” J. Def. & Tech., vol. 14(4), pp. 318-326, 2018.##
[20] Road, “Housing and Urban Development Research Center, Department of Rules and Regulations Compilation,” Iranian National Building Code 9: Design and Execution of Reinforced Concrete Structures, 1399. (In Persian)##
[21] A. Ghani Razaqpur and A. Tolba, “Blast Loading Response of Reinforced Cocrete Panels Reinforced With Externally Bonded GFRP Laminates,” J. Els. Comp., vol. 38, pp. 535 – 546, 2007.##
[22]  A. Tolba, “Response of FRP-Retrofitted Reinforced Concrete Panels to Blast loading,” Ph.D. Dissertation, Carleton University, Ottawa, Cannada, 2001.##
[23] C. Y. Tham, “Reinforced Concrete Perforation and Penetration Simulation Using AUTODYN-3D,” Finite. Elem. Anal. Des., vol. 41, pp. 1401-1410, 2005.## 
[24] M. Shahbazi and H. R. Karami, “Order a Book to Simulate the Phenomena of Impact, Explosion, Formation and Penetration with the Help of Autodyn Software,” Tehran, Sarvnagar, 1393. (In Persian)##