PULL-OUT STRENGTH OF BARS EMBEDDED IN HIG H-PERFORMANCE CONCRETE

This paper presents the results of a research program investigating th e bond between steel and high performance concrete using pull-out test s. The characteristics of the specimens were changed by varying the em bedded length, the bar diameter and roughness, and the age and strengt h of the concrete. The relationships between the pull-out load and the bond slip and the variations in the average bond stress with all of t he parameters studied here emphasized the important influence of the e mbedded roughness and concrete strength; the effects of the other para meters are far less important. Based on these results an extension is proposed of the present regulatory expressions for the ultimate bond s trength of concrete up to B60.