Volume 10, No. 4, 2016
Received: 2016/09/05, Accepted:
Authors:
Qasim M. Shakir;
Abstract:
In the present work, a non-linear finite element (FEM) analysis has been conducted in order to investigate the performance of high strength R.C. beams including large openings. Seven beams have been considered with different opening sizes (max. size of 120*480). Further, a beam of (120*600) mm opening has been studied to investigate the behavior of beams with larger openings.
To improve the performance of beams with large openings, two of the most commonly used methods in strengthening have been adopted. These are: increasing top and bottom steel ratios and jacketing of openings
with steel plates.
The analysis results showed that when the opening size was increased, the ultimate load capacity decreased gradually following a path very close to parabolic and that adopting high top and bottom steel ratios (about 8%) improved the ultimate load capacity by 59%. Also, it was found that strengthening the opening by a steel jacket of 3mm thickness improved the response of beams by 10% and 29% for cases of partial and full jacketing, respectively, while for a jacket of 5mm thickness, the capacity was improved by 22% and 44% for the two methods of jacketing.
Keywords:
Non-linear analysis, R.C. beams, High strength, Large openings, Cracking, Strengthening, Jacketing