Bond behaviour of deformed bars in NSC and HSC: Experimental study

In order to derive a general bond stress - slip relationship for deformed bars in concrete, tests have been carried out on bond behaviour of bars in normal strength and high strength concrete, for various confining conditions. This report focuses on a first test series, which was carried out on bars with large embedment lengths, cast into massive concrete specimens. The experimental results of this test series are used to formulate bond stress - slip relation. Proposed model considers the effect of steel yielding and permits optimum utilisation of increased bond strength of high strength concrete. This is an important extension with respect to the bond model formulation given in the CEB-FIP Model Code.