Experimental study of seismic torsional behavior of reinforced concrete walls

In this paper, the seismic torsional behavior of reinforced concrete walls has been studied experimentally. Reinforced concrete walls having 7, 6, and 5 aspect ratios have been produced on a 1/2 scale. Three specimens have been produced from each aspect ratio. In addition to these specimens, a reference specimen having a 6 aspect ratio has been produced. The reference specimen test has been used for determining the loading protocol. It has been tried to determine optimum load increase by changing load increments in the reference specimen test. Thus, ten seismic torsion tests have been carried out by using these specimens. The main purpose of the tests is to experimentally investigate the pure seismic torsional behavior of reinforced concrete walls which are under axial load. Moreover, it has been aimed to investigate the effects of the aspect ratio on torsional behavior using the tests. As a result of the study; cracking and maximum torsional moments, torque-twist angle curves, torsional stiffnesses, energy consumptions, damage patterns of the reinforced concrete walls have been obtained. It is observed from the results that the reinforced concrete walls having large cross-sections have greater torsional strengths and torsional stiffnesses. The average cracking and maximum torsional moments have increased 65.7% and 45.5% as the aspect ratio increased from 5 to 7. Furthermore, a significant decrease of torsional stiffness of the reinforced concrete walls has occurred with the occurrence of torsional cracking. The average ratios of post-cracking torsional stiffness to pre-cracking torsional stiffness have been calculated as 0.0781, 0.0922, and 0.0843 for the walls with 5, 6, and 7 aspect ratios, respectively. It has been concluded to study that choosing the aspect ratio of 5 or 6 would be appropriate in terms of torsional behavior.