مطالعه ی رفتار آزمایشگاهی تیربتن مسلح تقویت شده با میلگرد GFRP، ورق‌ های CFRP و فولادی تحت خمش خالص

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی مقطع دکتری، گروه مهندسی عمران واحد مرودشت دانشگاه آزاد اسلامی، ایران

2 استادیار گروه مهندسی عمران، واحد مرودشت، دانشگاه آزاد اسلامی، مرودشت، ایران.

3 اسنادیار گروه مهندسی عمران واحد مرودشت دانشگاه آزاد اسلامی مرودشت ایران

چکیده

متداول ترین روش مقاوم سازی تیرهای بتن مسلح، تقویت خمشی این تیرها با مصالح کامپوزیت می باشد. در مقاله حاضر چهار تیر با مقیاس واقعی به ابعاد 4200*250*250 میلیمتر ساخته شده است. ابتدا یک تیرتقویت نشده در آزمایشگاه تحت بارگذاری چهارنقطه ای قرار گرفت. سپس برای تقویت تیر در ناحیه ی خمشی، از سه تیر مشابه با استفاده از یک لایه ورق CFRP، یک لایه ورق فولادی ومیلگرد GFRP در ناحیه ی خمش تقویت و مقاوم سازی شد. تقویت تیرها در محدوده‌ی میانی صورت گرفته که بعد از بارگذاری در همه ی تیرها شکست خمشی اتفاق می‌افتد. نتایج نشان داد که تقویت تیربتن مسلح به صورت موضعی در ناحیه ی خمشی تاثیر چندانی برظرفیت باربری تیر نداشته اما باعث خارج شدن خرابی از محدوده‌ی خمشی محض تیر می شود. همچنین نتایج نشان می‌دهد با انجام تقویت موضعی در ناحیه خمشی، در بعضی از تیرها پیدایش اولین ترک ها در خارج از محدوده خمشی اتفاق می افتد در حالیکه شکست خمشی نهایی در محدوده میانی تیر اتفاق می افتد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Investigation of the Behaviour of Concrete Beams Reinforced by GFRP Bars and Strengthened by CFRP and Steel Sheets Under Pure Bending Moment

نویسندگان [English]

  • BABAK MANSORI 1
  • Ashkan Torabi 2
  • ARASH totonchi 3
1 PhD Student, Department of Civil Engineering, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran
2 2. Assistant Professor, Department of Civil Engineering, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran
3 اسنادیار گروه مهندسی عمران واحد مرودشت دانشگاه آزاد اسلامی مرودشت ایران
چکیده [English]

One of the conventional retrofitting methods for reinforced concrete beams is flexural strengthening of beams with CFRP materials. In this study, a full scale reinforced concrete beam is constructed and evaluated under four-point flexural test. Afterward, a same beam is retrofitted in flexural region by monolayer of CFRP. These experimental tests are carried out to be the basis of verification for numerical specimens. The first, an unreinforced beam is subjected to four-point loading in the laboratory. Then, to strengthen the beam in the flexural zone, three similar beams is reinforced and reinforced in the flexural zone using a layer of CFRP sheet, a layer of steel sheet and GFRP rebar. The reinforcement of the beams is done in the middle range, and after loading, bending failure occurred in all the beams. The results show that the reinforced concrete beam has much impact on carrying capacity, but would crash out of the range of the bending beam will be soon. The results also show that by performing local reinforcement in the flexural zone, in some beams, the first cracks occur outside the flexural range, while the final flexural failure occurs in the middle range of the beam.

کلیدواژه‌ها [English]

  • Retrofit
  • Reinforced Concrete Beam
  • CFRP Sheet
  • GFRP Bar
  • Steel Sheet
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