Abstract:
Many structural elements found in the structural system subjected to significant torsional moments that will alter the design values in reinforced concrete members. Torsional failure of structures is sudden and it needs to be prevented. Nowadays, different building codes in practice have no common provisions on torsion design. Some building codes account for concrete contributions in torsion resistance but others ignore it. On the other hand arrangement of shear reinforcement affects the shear capacity, but not much studied the effect of shear reinforcement arrangement on the torsional capacity of the reinforced concrete beams. In this study, the effect of shear reinforcement configuration with different concrete compressive strength on the torsional resistance of reinforced concrete beams was investigated both experimentally and analytically. From the experimental study, the ductile behavior, ultimate torsional strength, torque-rotation behavior and comparison of torque resistance with plain and reinforced concrete beams with and without stirrups, vertical and inclined shear reinforcement, longitudinal and inclined shear reinforcements and crack pattern or failure mode for concrete compressive strength (25Mpa & 45Mpa) of the tested beams. In addition to this compare the experimental test result with the analytical calculation of the test specimens. An experimental program investigating thirty types of specimens has carried out. The experimental results show that the torsional resistance of reinforced concrete beams is dependent on the orientation of stirrups and concrete compressive strength. The test results showed that the torsional resistance increased by 18.51% as the arrangement of stirrup changes from conventional vertical stirrup arrangement to the 450 inclined stirrup arrangements of RC beams. However, the concrete compressive strength increases the torsional resistance of concrete by 17.99%. In addition to the experimental test, the reinforced concrete beams with only vertical stirrup arrangement were analyzed by using the two codes, ACI318-19 and EN-2. The results obtained by experimental tests are compared to analytically calculated values by using the torsional provisions of ACI 318-19 and EN- 2. The comparison showed that both ACI and EN- 2 are conservative in predicting torsional resistance of RC beams which are examined in this study.