Document Type : Research Paper


Civil Engineering Department,University of Technology-Iraq, Alsina’a street, P.O BOX 10066 Baghdad, Iraq.


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.


  • The inclination effect on the concrete column decrease confinement.
  • There are certain angles that we can adopt in the design of inclined columns to avoid reducing confinement.
  • The use of high strength concrete contributes greatly to avoiding the reduction of confinement in the inclined columns.


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