DIYALA JOURNAL OF ENGINEERING SCIENCES

Abstract

This paper is an experimental study to investigate the effect of concrete compressive strength on the structural behavior of continuous reinforced concrete deep beams to utilize the results on the piles caps works. Three nominal concrete compressive strengths 50, 60 and 70 MPa obtained by self-compacting concrete were frequently used with four groups of shear span-to-depth ratios 5.71, 1.25, 1.08 and 0.95 to produce twelve continuous beams; three of them are shallow and the rest are deep. The comparisons were designed to reveal the variation in the structural behaviors among the shallow and deep specimens from a side, and among the deep specimen from another side.
The experimental program concentrated on the ultimate strength, load-deflection curve, cracking and failure mode of the specimens. The results revealed that the concrete compressive strength is an effective factor on the behavior of the deep beam and when its value increased the ultimate strength and the serviceability of specimen can be improved about 48% whilst the enhancement achieved in shallow beams about 9%. The percentage of the obtained improvement for a specimen can be increased by decreasing its shear span-to-depth ratio.