Effects of embedded reinforcement on measured strength of concrete cylinders

The effects of embedded steel bars on the strength of concrete cylinders as affected by various parameters were investigated. These parameters were the size and the length/diameter ratio of the cylinders, the positioning of the steel bar, the bar size and the cube strength of concrete. For a length/diameter ratio of 1·0, the experimental results differed significantly from the calculated values based on the correction formula recommended in BS 1881, Part 120. The inclusion of steel up to 4% by volume in 100 mm × 100 mm cylinders did not have any detrimental effect, but for deformed high tensile steel bars of 13–20 mm diameter, increases of up to 9% in the measured strengths over those of the control specimens were observed.