تاثیر مقاومت بتن و چسبندگی ورقهای CFRP انعطاف پذیر بر مقاومت نهایی تیرهای بتنی

مهندسی عمران فردوسی

مقاله 3، دوره 26، شماره 2، شهریور 1394، صفحه 34-46   

نوع مقاله: پژوهشی

شناسه دیجیتال (DOI): 10.22067/civil.v26i2.18398

نویسندگان

محمود نادری^* ؛ علی خونساری

دانشگاه امام خمینی (ره)

چکیده

در میان روش‌های مختلف مقاوم‌سازی استفاده از ورق‌های پلیمری مسلح به الیاف FRP با استقبال روبه‌رشدی مواجه بوده است. در استفاده از FRP، مقاومت سطحی بتن بستر تأثیر تعیین‌کننده‌ای بر مقاومت چسبندگی بین FRP و بتن دارد. لذا در این تحقیقات، مطالعه‌ی آزمایشگاهی و تحلیلی بر روی بیست نمونه تیر بتنی ساخته شده از پنج مقاومت مختلف بتن به انجام رسیده است. با این‌که نیمی از نمونه‌های یاد شده با ورق‌های CFRP تقویت شده‌اند ولی نیمی دیگر به‌عنوان شاهد مورد مقایسه قرار گرفته‌اند. تقویت تیر ها به‌صورت سه‌وجهی با ورق‌های پلیمری مسلح به الیاف کربنی تک‌سویه CFRP صورت گرفته است. مقاومت چسبندگی CFRP به بستر بتنی با استفاده از روش «پیچش» به‌طور مستقیم اندازه‌گیری گردیده است و نتایج به‌دست آمده با نتایج حاصل از شکست نمونه‌ها در آزمایش استاندارد خمشی مقایسه گردیده‌اند. در نهایت تأثیر مقاومت سطحی بتن و مقاومت چسبندگی CFRP به بتن، بر مقاومت نهایی تیرهای بتنی تقویت شده با ورق‌های CFRP ارائه شده است.

کلیدواژه‌ها

آزمون پیچش؛ مقاومت بتن؛ تیر بتنی؛ چسبندگی

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