مقاوم‌سازی آزمایشگاهی تیرهای بتن مسلح ضعیف با فناوری لایه‌های کامپوزیت سیمانی الیافی مسلح توانمند HPFRCC

نوع مقاله : مقاله کامل پژوهشی

نویسندگان

دانشکده مهندسی عمران، دانشگاه سمنان

چکیده

وجود سازه ­های قدیمی، ضعف­ های موجود در طراحی و اجرای سازه­ ها، استفاده از مصالح کامپوزیت سیمانی الیافی مسلح توانمند HPFRCC با عملکرد بالا در جهت مقاوم ­سازی، مورد توجه واقع شده است. در این مقاله تأثیر این مصالح بر عملکرد سازه­ای پنج تیر بتن مسلح تقویت شده با این مصالح به ­صورت آزمایشگاهی بررسی گردید. یک تیر مرجع و چهار تیر مقاوم­ سازی شده با یک لایه نازک HPFRCC با الیاف پلی­ پروپیلن با دو نوع مصالح و دو شیوه اجرای متفاوت، تحت آزمایش چهارنقطه­ ای خمش خالص قرار گرفت. نتایج نشان داد که تأثیر مقاوم­ سازی با HPFRCC در شکل ­پذیری نمونه­ ها بیش از تأثیرشان در ظرفیت خمشی تیرها بود و حداکثر افزایش در ضریب شکل ­پذیری و ظرفیت خمشی ناشی از مقاوم ­سازی برابر 64 و 31 درصد بود و سخت­ شوندگی ناشی از پل زدن الیاف در نمودار بار- تغییر مکان نمونه ­های تقویت شده مشهودتر است. میزان جذب انرژی در بهترین نمونه تقویت­ شده با این مصالح تا 90 درصد نسبت به نمونه مرجع افزایش یافت و نتایج آزمایشگاهی تا حدود 11 درصد بیش از مقادیر به ­دست آمده از فرمول­ های تحلیلی بود.

کلیدواژه‌ها


عنوان مقاله [English]

Experimental Strengthening of Deficient RC Beams with Advanced HPFRCC Composite Layers Reinforced with PP Fibers

نویسندگان [English]

  • Mohammad Kazem Sharbatdar
  • Mehdi Ahmadpanahi
Faculty of Civil Engineering, Semnan University, Semnan, Iran
چکیده [English]

The old existing structures and design and construction deficiency are the main to concentrated on using high performance fiber composite HPFRCC for strengthening, Nowadays. Because of increasing demands at the construction industry, it is required to using new material with high quality in this regards. Therefore based on necessities in our country for having high performance composite materials such as HPFRCC, this material are spreadly using as strengthening materials. The main research issues in this regards is on composite ingredients and design mixes, stress-strain curves and material behavior. Even though some structural application are conducted on HPFRCC material (Alwan, 1994; Naaman, 2005), it is required to performing new experimental and analytical researches on material mixes with different fibers and percentages and flexural behavior of reinforced concrete specimens strengthened with this material and their durable performance (Hemmati, 2016; Ehsani, 2019). The effect of structural performance and different arrangements of new material layers of this advanced material on five strengthened reinforced concrete beams was experimentally investigated in this paper and their results were compared to each other’s.

کلیدواژه‌ها [English]

  • Strengthening
  • Experimental investigation
  • Flexural Behavior
  • Ductility
  • HPFRCC
Abbaszadeh MA, Sharbatdar MK, Kheyroddin A, “Performance of Two-way RC Slabs Retrofitted by Different Configurations of High Performance Fibre Reinforced Cementitous Composite Strips”, The Open Civil Engineering Journal, 11, 650-663, 2017.
Al.Chaar Gh K, Lamb GE, “Design of Fiber-Reinforced Polymer Materials for Seismic Rehabilitation of Infilled Concrete Structures”, US Army Corps of Engineering, 2002.
Alwan J, Naaman AE, “New formulation for the elastic modulus of fiber reinforced quasi brittle matrices”, ASCE Journal of Engineering Mechanics, 120 (11), 2443-2460, 1994.
Bai JW, “Seismic Retrofit for Reinforced Concrete Building Structures”, Consequence- Based Engineering (CEB), Institute Final Report- Texas University- August, 2003.
Dehghan M, “Experimental and analytical investigation of reinforment details in couple RC beams cast with HPFRCC”, Master Thesis, Semnan University, 1390.
Ehsani R, Sharbatdar MK, Kheyroddin A, “Ductility and moment redistribution capacity of two-span RC beams, Magazine of Civil Engineering”, 90 (6), 104-118, 2019.
Fallah MM, Sharbatdar MK, Kheyroddin A, “Experimental Strengthening of the Two-way RC Slabs with High Performance Fiber Reinforced Cement Composites Prefabricated sheets”, Journal of Rehabilitation in Civil Engineering, DOI: 10.22075/jrce.2018.14532.1266, 2017.
Ferrari VJ, Hanai JB, De Souza RA, “Flexural strengthening of reinforcement concrete beams using high performance fiber reinforcement cement- based composite (HPFRCC) and carbon fiber reinforced polymers (CFRP)”, Construction and Building Materials 2013, 48, 485-498.
Fischer G, Li VC, “Effect of matrix ductility on deformation behavior of steel reinforced ECC flexural members under reversed cyclic loading conditions”, ACI Structural Journal, 2002, 99 (6), 781-790.
Habel H, Gauvreau P, “Response of UHPFRC to impact and static loading”, Cement and Concrete Composites, 2008, 938-946.
Hemmati A, Kheyroddin A, Sharbatdar MK, “Plastic Hinge Rotation Capacity of Reinforced HPFRCC Beams, ASCE's Journal of Structural Engineering, 2015, 141(2).
Hemmati A, Kheyroddin A, Sharbatdar MK, Park Y, Abolmaali A, “Ductile behavior of high performance fiber reinforced cementitious composite (HPFRCC) frames. Constr Build Mater”, 115, 681-9. doi:10.1016/j.conbuildmat.2016.04.078, 2016.
Jeyasehar AC, Balamuralikrishnan R, “Strengthening of structures by HPFRCC laminates”, Asian Journal of Civil Engineering, 2012, 13 (1), 29-42.
Kanakubo T, Shimizu K, Kanda T, Nagai S, “Evaluation of bending and shear capacities of HPFRCC members toward the structural applications”, Proceedings of the Hokkaido University COE Workshop on High Performance Fiber Reinforced Composites for Sustainable Infrastructure System– material modeling, structural design and application, Japan, 2007.
Krenchel H, Stang H, “Stable microcracking in cementitious materials”, In Brittle Matrix Composites 2. A.M. Brandt and J.H. Marshall, eds., 1989, 20-33.
Liu J, “Rehabilitation of Seismically Deficient Reinforced Concrete Structures-State of the art”, University of Alberta; An Interdisciplinary Journal, 2006.
Li VC, “Engineered cementitious composites (ECC) -material, structural, and durability performance”, University of Michigan, Ann Arbor, 2007, MI 48109.
Majumdar A J, Ryder J R, “Glass fiber reinforcement of cement products”, Glass Technol, 1968, 9 (3), 78-84.
Mishra D, Li VC, “Performance of ductile plastic hinge designed with ECC”, UMCEE Rep. No. 9506, University of Michigan, 1995.
Miyazato Sh, Hiraishi Y, “Durability against Steel Corrosion of HPFRCC with Bending Cracks”, Journal of Advanced Concrete Technology, 2013, 11 (4), 135.
Naaman AE, Reinhardt HW, “Setting the stage: toward performance-based classification of FRC composites”, In High Performance Fiber Reinforced Cement Composites (HPFRCC-4), Proc. of the 4th Int’l RILEM Workshop, A.E. Naaman and H.W. Reinhardt, 2003.
Naaman AE, Reinhardt HW, “High performance fiber reinforced cement composites”, HPFRCC- 4, International RILEM Report. Materials and Structures, 2004, 36, 710-712.
Naaman AE, Reinhardt HW, “Proposed classification of FRC composites based on their tensile response”, Proceeding of symposium honoring S. Mindess, N. Banthia, Editor, University of British Columbia, Canada, 2005.
Naaman AE, “Rotation capacity of high performance fiber reinforced cement composite beams”, CONSEC 07, 2007.
Obaidat YT, Heyden S, Dahlblom O, Abu-Farsakh G, Abdel-Jawad Y, “Retrofitting of reinforced concrete beams using composite laminates”, Construction and Building Material, 2011, 25 (2), 591-7.
Parra-Montesinos GJ, Peterfreund SW, Chao SH, “Highly damage-tolerant beam-column joints through use of high-performance fiber-reinforced cement composites”, ACI Structural Journal, 2005.
Parra-Montesinos G, “Proposed addition to ACI Code 318-05 on shear design provisions for fiber reinforced concrete members”, 2006.
Ferreira D, Bairán J, Marí A, “Numerical simulation of shear-strengthened RC beams”, Engineering Structure, 2013, 46, 359-374.
Stang H, Li VC, “Classification of fiber reinforced cementitious materials for structural applications”, in Fiber-Reinforced Concretes, Proc, BEFIB 2004, Ed. M.di Prisco, R. Felicetti and G.A. Plizzari, 2004, 197-218.
Suwannakarn SW, “Post-cracking characteristics of high performance fiber reinforced cementitious composites”, PhD Dissertation, Michigan University, 2009.
Suwannakarn SW, Post-cracking characteristics of high performance fiber reinforced cementitious composites: PhD Thesis, University of Michigan, 2009.
Vandewalle L, “RILEM TC 162-TDF: Test and design methods for steel fibre reinforced concrete”, Sigma-epsilon-design method- Final Recommendation. Materials and Structures 2003, 36 (262), 560-567.
Wang S, “Micromechanics based matrix design for engineered cementitious composites”, PhD Thesis, University of Michigan, 2005.
Yang EH, Yang Y, Li VC, “Use of high volumes of fly ash to improve ECC mechanical properties and material greenness”, ACI Materials Journal, 2007.