Majid M. Kharnoob, Ali A. Abdulhameed, Zinah W. Abbas
Abstract
Torsion rarely occurs by itself only. It is usually combined with other
actions such as flexure and shear. Even-though, the performance of high
strength reinforced concrete continuous beams under pure torsion is
investigated in this study. Torsional moments were acted at the external
supports via applying external loads far away from the vertical plane of
bending at various eccentricities from the axis of the RC beams until failure.
Variables considered in this study are absolute vertical displacement of the
external supports, torsional moment’s capacity, and angle of twist and initial
cracking stages of loading. Four increments of 10 cm in each of loading
eccentricity started from 30 cm arm of loading were investigated.
According to experimental results; when applied load eccentricity increased
from 30cm to 60cm, the absolute vertical displacement increased about
56.315% and the angle of twist increased about 55.44% at failure while the
generated twisting moments increased about 25.58% . It has been also found
that the ultimate failure loading capacity of beams decreased about 37.21%
when the load eccentricity increased from 30cm to 60cm. Furthermore, the
initial cracking was monitored; it was found that cracking occurs at higher
stages of loading with low loading eccentricity. The initial cracking records
appeared at 79.07%, 77.78%, 74.3% and 66.67% of loading when loads arm
were 30, 40, 50 and 60cm, respectively.
زينة وليد عباس | zinah waleed Abass | 13746