| Abstrakt: |
Reinforced concrete deep beams are commonly used in high-rise structures to withstand heavy loads. In the construction of deep beams, openings are often enclosed for accessibility and to allow access to necessary services like power, ventilation, and network systems. However, Deep beam openings can cause several problems with performance, such as decreased beam strength, significant cracking, and deflection. As a result, this study was carried out to investigate the performance of self-compacting concrete deep beams with longitudinal openings reinforced by steel tubes. The behavior of five specimens have been studied in this research; different longitudinal square and rectangular openings (square openings in a tension zone with dimensions (4in, 3in) and rectangular openings with sizes (3 in*1.5in) were used in this study. All specimens have the same dimensions (1600mm length, 425mm total height, and (250mm) width, for comparison purposes, one of these specimens was cast with a solid section (without longitudinal opening). The main problems included in this research are the presence of longitudinal openings, size of openings, voiding ratio, and opening reinforcement. The cracks pattern, deflection, and load capacity were all measured and discussed. The experimental study reveals that longitudinal openings reduce the loading capacity of self-compacting (SCC) reinforced deep concrete beams; moreover, Increasing the opening size also lowers the load capacity. The structural performance of small openings was similar to that of the reference specimen. The results showed that the reduction in ultimate and cracking load of beams with square openings was (21.57 to 24.31) percent and (17.65 to 26.47) percent, while the reduction in ultimate load and cracking load in beams rectangular openings was(20.59 to 31.37) percent and (11.18 to 34.71)percent compared with the reference specimen, due to the sharp edges in rectangular, which led to stresses concentration in the corners and large failure in the specimens. Using steel pipes to strengthen the longitudinal opening effectively increased stiffness and load carrying capacity of deep beams. [ABSTRACT FROM AUTHOR] |
