بررسی عددی تاثیر شکل مقطع ستون، مقاومت ملات و تعداد لایه‌های trc بر رفتار لرزه‌ای ستون‌های بتنی مسلح

استفاده از بتن مسلح شده با منسوج t‌r‌c از روش‌های نوین تقویت سازه‌های بتنی است که به دلیل وزن کم، مقاومت بالا، عدم تغییر در ابعاد المان‌های تقویت شده و سهولت در اجرا در سال‌های اخیر به آن توجه شده است. هدف از مطالعه‌ی حاضر، بررسی کارایی استفاده از روش اخیر برای مقاوم‌سازی ستون‌های بتنی با درصد آرماتور پایین است که نیازمند تقویت هستند. در مطالعه‌ی حاضر، پس از صحت‌سنجی مدل‌های ساخته شده در نرم‌افزار اجزاء محدود آباکوس با آزمایش‌های انجام شده، نسبت به بررسی و مقایسه‌ی اثر پارامترهای مختلف موثر در تقویت ستون‌های بتنی اقدام شده است. در مطالعه‌ی حاضر، پارامترهای مختلفی، مانند: شکل هندسی مقطع، مقاومت ملات، تعداد لایه‌های منسوج بررسی شده و ظرفیت نیروی جانبی، الگوی ترک و تنش در سطح بتن و ملات و تسلیم میلگردها در ستون‌های بتنی تقویت شده مقایسه و ارزیابی شده است.

Numerical investigation of the effect of crosssection shape, mortar strength, and number of textile layers on the cyclic behavior of RC columns

Repairing and strengthening of structures are unavoidable. The main reasons for repairing and strengthening concrete structures are improper design or construction, weakness of the structural elements, changing the usage of the building and damages that happen in structural elements. There are various ways for strengthening the vulnerable structures. In recent years, usage of high strength concrete reinforced with textile meshes (Textile Reinforced Concrete (TRC)) for strengthening the concrete structures has become a proper alternative for retrofitting the buildings. Using reinforced concrete with TRC is one of the new methods for strengthening the concrete structures. This method has become popular in recent years due to its light weight, high strength, no changes in the dimensions of reinforced concrete elements, and ease of use. The aim of this study was to evaluate the efficiency of this method in strengthening concrete columns with a low reinforcement ratio that need reinforcement. In this investigation, after verifying two models simulated by finite element software (ABAQUS) with experimental results, eight models were studied numerically. The models consisted of columns and supporting beams and they were categorized into four groups by different parameters which are effective in strengthening the concrete columns. In this paper, various parameters such as geometry of crosssection, mortar strength, and number of textile layers were investigated. The columns and their connections to supporting beams were strengthened with TRC. Models strengthening were carried out using vertical layers plus horizontal layers of textile meshes in cement mortar. Lateral force capacity, crack, and stress pattern on concrete and mortar surfaces and yielding of rebars in reinforced concrete columns were compared and evaluated. The cyclic behaviors of all TRC strengthened models were improved compared to nonstrengthened ones.