بررسی رفتار ستون های بتن مسلح ساخته شده از بتن با مقاومت بالا و محصور شده با غلاف GRP و دورپیچ FRPC

ساجدی, سیدفتح اله; شفیعی نیا, محسن; رضوی طوسی, وحید

doi:10.22065/jsce.2018.138470.1602

بررسی رفتار ستون های بتن مسلح ساخته شده از بتن با مقاومت بالا و محصور شده با غلاف GRP و دورپیچ FRPC

نوع مقاله : علمی - پژوهشی

نویسندگان

¹ دانشیار، گروه مهندسی عمران، واحد اهواز، دانشگاه آزاد اسلامی، اهواز، ایران

² گروه عمران دانشگاه آزاد اسلامی اهواز

³ گروه عمران دانشگاه جندی شاپور دزفول

10.22065/jsce.2018.138470.1602

چکیده

این مقاله نتایج انجام آزمایش فشار محوری بر ستون‌های بتن‌مسلح ساخته شده از بتن با مقاومت بالا که با استفاده از غلاف لوله‌های پلاستیکی تقویت‌شده با الیاف شیشه و هم‌چنین دورپیچ کامپوزیت‌های الیاف پلیمری تقویتی ، محصور شده‌اند، را ارائه می‌کند. هدف این مطالعه، بررسی رفتار و ظرفیت باربری ستون‌های بتن‌مسلح محصور شده با غلاف GRP و دورپیچ ورق‌های CFRP زیر بارهای فشاری است. در این تحقیق تأثیر استفاده از غلاف GRP، دورپیچ CFRP و هم‌چنین تعداد لایه‌های CFRP بررسی شده است. در این تحقیق 6 ستون بتن‌مسلح استوانه‌ای از بتن با مقاومت بالا تهیه شدند، نصف ستون‌ها (گروه1) دارای غلاف GRP و نصف دیگر (گروه2) فاقد غلاف بودند. از هر گروه، یک ستون هیچ‌گونه لایه تقویتی CFRP نداشت، یک ستون با یک لایه و ستون دیگر با دو لایه ورق تقویتی دورپیچ شدند. تمام ستون‌ها تحت نیروی فشاری متمرکز آزمایش شدند. نتایج نشان داد که استفاده از دورپیچ CFRP و غلاف GRP باعث بهبود مقاومت فشاری و شکل-پذیری ستون‌های بتن‌مسلح می‌شود. افزودن یک لایه و دو لایه دورپیچ CFRP به طور میانگین باعث افزایش %2/10 و %8/24 مقاومت فشاری ‌گردیدند، درحالی که استفاده از غلاف GRP به طور میانگین باعث افزایش 38/3 برابری مقاومت فشاری ستون‌ها شده است. نتایج حاکی از آن است که گرچه دورپیچ CFRP و غلاف GRP هر دو ایجاد محصوریت می-کنند، ولی غلاف GRP به خاطر محصوریت بیش‌تر، تاثیر بسیار افزون‌تری بر افزایش مقاومت فشاری و همین‌طور شکل‌پذیری ستون‌های بتن‌مسلح دارد.

کلیدواژه‌ها

موضوعات

مرمت و مقاوم سازی سازه ها

عنوان مقاله [English]

Investigation on the behaviour of reinforced concrete columns made of high-strength concrete, enclosed with GRP casing and CFRP sheets

نویسندگان [English]

Fathollah Sajedi ¹
Mohsen Shafieinia ²
Vahid Razavi Toosi ³

¹ Associate Professor, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran

² Department of Civil Engineering, IAU of Ahvaz

³ Department of Civil Engineering, Jundi Shapur University of Technology

چکیده [English]

This paper presents the results of an axial pressure test on reinforced concrete columns made of high-strength concrete, which are encapsulated using a glass-fiber reinforced plastic pipes (GRP) and also with fiber reinforced polymer (FRP). The purpose of this study was to investigate the load bearing behavior of concrete columns enclosed with GRP casings and CFRP composites under compressive loads. In this research, the effect of using the GRP casings, CFRP sheets, and also the number of CFRP layers has been investigated. In this research, six circular reinforced concrete columns were manufactured from high-strength concrete, half of columns (group 1) had a GRP casing and the other half (group 2) without casing. From each group, a column had no CFRP reinforcement layer, a column with one layer and another column with two layers of CFRP reinforcement. All columns were tested under concentrated compressive force. The results showed that the use of CFRP sheets and GRP casings improved the compressive strength and durability of the reinforced columns. The addition of a layer and two layers of CFRP increased an average of 10.2% and 24.8% in compressive strength, while the use of a GRP casing increased averagely 3.83 times in compressive strength of the columns. The results indicate that although the CFRP sheets and the GRP casings are both enclosed, the GRP casings, due to their greater enclosure, have a much greater effect on the compressive strength and the ductility of the reinforced concrete columns.

کلیدواژه‌ها [English]

Reinforced concrete column
High-strength concrete
GRP casing
CFRP sheet
Axial force
Ductility

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