EFFECT OF EMBEDDED BAR ON CYLINDER STRENGTH

Abstract

Research which included tests on 174 cylinders an 24 cores, mainly of 100 mm diameter by 100 mm length is described in this report. These tests were made to determine if the inclusion of reinforcement steel (0.3% to 4% by volume of steel) placed in different configurations in moulded concrete cylinders has a measurable effect on the compressive strength. Past research on the influence of steel reinforcement in concrete cores has been carried out with moulded cylinders of length-diameter ratio between 1.5 to 2.0. It was concluded that the presence of steel reinforcement reduces the measured strength. However in this present study, when cylinders of length-diameter ratio of 1.0 were used, results indicated there is no significant difference in measured strength with the presence of steel. On the contrary, an increase in percentage volume of steel causes a very small increase in strength. In the light of this trend, a correction factor for steel inclusion in cores of length-diameter ratio of 1.0 to 1.5 recommended in BS 1881:Part 120 may need to be reviewed.