بررسی آزمایشگاهی رفتار دال های بتن آرمه دوطرفه تقویت شده با روکش های پیش ساخته کامپوزیت سیمانی الیافی توانمند (HPFRCC)

نوع مقاله : علمی - پژوهشی

نویسندگان

1 دانشگاه سمنان

2 دانشیار، دانشکده مهندسی عمران، دانشگاه سمنان، سمنان، ایران

3 استاد، دانشکده مهندسی عمران، دانشگاه سمنان، سمنان، ایران

چکیده

سازه‌های بتن آرمه به دلایل مختلفی از جمله خطاهای حین طراحی و یا ساخت، نیاز به تقویت و بهسازی داشته و تقویت اعضای سازه‌ای در اغلب موارد بسیار اقتصادی تر از ساخت مجدد سازه می‌باشد. استفاده از کامپوزیت‌های سیمانی مسلح شده با الیاف دارای عملکرد بالا(HPFRCC) که دارای رفتار سخت شدگی کششی هستند در مقاو‌م‌سازی ساز‌ه‌های بتنی طی چند سال اخیر توسعه بسیاری یافته‌است. در این مقاله امکان استفاده از HPFRCC برای تقویت دال‌های بتن آرمه دوطرفه بررسی شده‌است. در مجموع پنج دال دوطرفه ساخته شده و تا رسیدن به مرحله گسیختگی آزمایش شده‌است که یکی از دال‌های تقویت نشده به عنوان دال کنترل و بقیه دال‌ها به شکل‌های مختلفی تقویت شدند. تقویت‌ها در دو روش، یکبار نصب روکش در ناحیه کششی و یکبار نصب روکش هم در ناحیه کششی و هم در ناحیه فشاری، هر دفعه هم با درصدهای مختلف الیاف صورت گرفته‌است. رفتار خمشی و حالات ترک‌خوردگی، تسلیم و گسیختگی مربوطه نمونه دال‌های آزمایشگاهی مورد ارزیابی قرار گرفتند. نتایج نشان داد که نصب روکش‌های پیش‌ساخته HPFRCC بطور قابل ملاحظه‌ای باعث بهبود عملکرد خمشی دال‌های تقویت شده گردیده‌است، به طوری-که شکل‌پذیری، میزان جذب انرژی، مقاومت در برابر ترک‌خوردگی و سختی اولیه دال‌ها افزایش و عرض ترک کاهش یافته‌است. بنابراین از آنها می‌توان برای تقویت دال‌های ضعیف استفاده کرد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Study of the Performance of Two-way RC Slabs Retrofitted with High Performance Fibre Reinforced Cement Composite (HPFRCC) prefabricated laminates

نویسندگان [English]

  • M. Mahdi Fallah Bafghi 1
  • Mohammad Kazem Sharbatdar 2
  • Ali Kheyroddin 3
1 Semnan University
2 Associate Professor, Civil Engineering Faculty, Semnan University, Semnan, Iran
3 Professor, Faculty of Civil Engineering, Semnan University, Semnan, Iran
چکیده [English]

Reinforced concrete structures need to be strengthened and retrofitted for various reasons, including errors during design and/or construction, and in most cases reinforcement of structural elements is much more economical than rebuilding the structure. Using HPFRCC with tensile stiffening behaviour has been developed to reinforce the concrete structures over the recent few years. In this paper, the usage possibility of HPFRCC for reinforcing two-way reinforced concrete slabs has been studied. .A total of five two-way slabs were constructed and tested to reach the rupture stage , that one of not reinforced slabs as control slab, and the rest of the slabs were reinforced in various forms. The reinforcements were carried out in two ways, once by installing veneer in the tensile area and once by installing veneer in both tensile area and compression area each time with different percentages of the fibres.
The behaviour of bending and cracking, yielding and rupture of the laboratory samples were evaluated. The results revealed that the installation of pre-fabricated laminates of HPFRCC significantly improved the bending performance of reinforced slabs, so that the deformability, energy absorbance value, resistance to cracking and initial hardness of the slabs was increased and the crack width decreased. Therefore, they can be used to reinforce the weak slabs.

کلیدواژه‌ها [English]

  • "Two-way slab"
  • "PPS fibres"
  • "Reinforcement"
  • "HPFRCC"
  • "Bending performance"
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