This study is part of a larger research work aimed to study the effects of fiber
content, fiber type (corrugated shape and hooked-end), amount of web reinforcement and
axial compression stress, on the shear behavior of high strength fiber reinforced concrete
(HSFRC) beams. To the author’s knowledge, the effect of applying axial compression forces,
to the HSFRC beams, has not yet been studied. Nineteen simply supported HSFRC beams
were subjected to axial compression forces and tested under two-point vertical loading for
three values of shear span to depth ratio. It was found that the shear strength of beams
subjected to axial compression stress level equals 0.1, is higher than that in the literature for
beams tested without applying axial stress by a range of 22% -98%. Increasing the axial
compression stress level to 0.2 led to an increase in the first crack load, ultimate load by 24%
and 10%, a reduction in the deflection by (19-30%), compared with those subjected to axial
compression stress level equals 0.1. In addition, a combination of web reinforcement and
fibers resulted in a significant increase in the cracking and ultimate loads by 123 and 59%,
respectively, over those of the reference beam. A new formula is proposed for predicting the
experimental shear strength of HSFRC beams subjected to axial compression forces. The
results obtained by the proposed formula are in better agreement with the test results when
compared with the predictions based on the empirical equations proposed by other
investigators |
