NEW PROPOSED FORMULA FOR R.C. COLUMN SLENDERNESS RATIO LINKED WITH CONCRETE COMPRESSIVE STRENGTH AND STRESSES ON COLUMNS

Many codes for reinforced concrete columns design adopted by various countries are in fact built upon empirical formulae. However, Egyptian code adopted slenderness limit 30 for braced columns and 23 for unbraced columns. The mentioned values in codes do not change with different variables such as concrete compressive strength and stresses on columns as well as increases in column dimensions. This paper aimed to study the influences of parameters that affected slenderness ratio such as concrete compressive strength and stresses on columns. Also, the present study aimed to find a formula for slenderness ratio linked with concrete compressive strength and stresses on column pu/a. (The results of the proposed formula fit very well with ECP 203 code and showed that an increase in slenderness limits with increase compressive concrete strength (f cu) as well as decrease stresses on columns. Thus, the effect of compressive concrete strength and stresses on columns should be taken into consideration in calculating the slenderness limits.