EVALUATING THE EFFECT OF CROSS SECTIONAL STEEL RATIOS ON CONCRETE DENSITY AND ITS DESIGN IMPLICATION

In this paper, a case study has been taken from construction industry of Pakistan to evaluate the effect of using different percentages of steel rebar's in cross section of structural members. Four different construction sites from Karachi city were surveyed and their heaviest column cross sections were observed for estimating the concrete density. In total sixteen concrete columns are studied in this research and their respective densities calculations were made. Columns are selected in such a way that all have different cross section and different areas of steel in it. From each cross section, the volume of concrete and steel were determined and used to estimate the density of reinforced concrete. The current design density and estimated density is compared and increment in density is calculated. Using the analytical results, a dead load factor for design of structural members is suggested to overcome the effect of increased density of RC members and overall factor of safety were calculated using different ratio of live and dead load at different strength reduction factors.