Combined effect of stirrup volumetric ratio with vertical steel bars on the behavior of r. c. columns under axial loads

Abstract EN

Most international codes in the design of R.

C.

columns use only the vertical steel bar effect in determining ultimate load capacity.

No combination effect of stirrup volumetric ratio with vertical steel bar has been taken in design of the R.

C.

column.

The present study deals with an experimental and analytical analysis of the behavior of reinforced concrete columns with different percentage of vertical steel bars (µ) and stirrups volumetric ratio (ρ v).

A total of sixteen R.

C.

columns with cross-section (250x250x1000) mm were tested and divided into four groups and tested until failure under axial load.

Group 1 consisted of four columns with vertical steel bars with (µ) = 0.18% and stirrups (ρ v) = (0.27% , 0.48% , 0.75 and 1.09% ).

Group 2, 3 and 4 having same stirrups (ρ v) % with vertical bars (µ) = (0.32% , 0.50% , 0.75% ) respectively.

The test results showed that increasing in the percentage of vertical steel bars (µ) = (0.18% up to 0.73% ) give an increase of the ultimate failure load up to 9.7% .

Also, increasing percentage of stirrups volumetric ratio (ρ v) = (0.27% up to 1.09 % ) gives an increase of the ultimate failure load up to 12.3% and enhancement in ductility of columns Thus, the increase in the ultimate load of columns due to stirrups effect should be taken into consideration in the design of R.

C columns.

The analytical analysis (FEA) models can be simulate the experimental behavior of tested columns and can be suitable to reduce time and cost.