Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Confinement


Effect of Inclination of Rectangular Reinforced Concrete Short Columns on the Confinement

Eyad K. Sayhood; Bassman R. Muhammed; Ahmed A. Hatem

Engineering and Technology Journal, 2021, Volume 39, Issue 12, Pages 1821-1827
DOI: 10.30684/etj.v39i12.437

The main objective of this paper is to study the confinement of the rectangular reinforced concrete short inclined columns. This paper was based on theoretical analysis using the MATLAB program according to Universal Codes, and variables that were carefully selected to be the most influential factor. The angle of the inclination (α) was taken as a major variable in the paper, in addition other variables which in turn affect directly on the behavior of inclined columns such as the percentage of reinforcing steel in the concrete section of the column (ρ), the compressive strength of the concrete (fʹc), yield strength of steel bars (fy) and effective depth ratio (γ). The results show that best ratio of reinforcing steel that improves the value of the confinement ranges from 0.4 - 0.6 which leads to an increase in the confinement of (60 – 100) %, and these rates increase with increasing α, and the increase in fʹc leads to a significant increase in the confinement, especially when HSC is used..On the other hand, decreasing  fy leads to increase in confinement, and the value of the γ had a considerable effect on the confinement that was decreased by about 11% when γ equals 0.9, compared with the corresponding γ equals 0.6.

Bond Strength-Splice Length in Concrete Beams Confined by Transverse Reinforcement

Sameh Badry Tobeia Shuker

Engineering and Technology Journal, 2010, Volume 28, Issue 2, Pages 322-339

This work aim to study the effect of transverse reinforcement , area of splice
bar, concrete cover thickness , rib area and the increasing in concrete strength (highstrength
concrete) on bond strength between concrete and reinforcing spliced bars .
Therefore, a new simple equation is derived for beams with spliced bars and
confined by transverse reinforcement to calculate bond strength and reflects the
effects of these factors .Where many of existing codes and provisions used to
calculate the spliced strength do not include or reflect the influencing of these factors
in bond strength estimation . Based on experimental results from previous works ,
(116) confined beams with spliced bars are investigated in this study , where
concrete compressive strength ( c f ¢
) ranging from 25 MPa to 113.793 MPa ,amount
of transverse reinforcement vary in a wide range and , conventional and high
relative rib area of deformed bars are present in these beams . The proposed method
exceed the limitation of ( f MPa c ¢ £ 69 ) that given by ACI code .Where the
proposed method is examined and applicable for concrete compressive strength up
to 113 MPa . Also, in this work the second root of c f ¢
is examined , as concrete
strength increased with high-strength concrete , to reach a suitable value for both
normal and high- strength concrete and to be more appropriate with the heavy
present of transverse reinforcement . Power of (0.35) is adopted and used in this
work instead of the second root of c f ¢