Size Effect on Failure of Bond Splices of Steel Bars in Concrete Beams

Abstract

The results of reduced-scale failure tests of simply supported four-point-bend beams of different sizes, containing lapped bond splices of smooth (undeformed) longitudinal reinforcing bars, are reported. The tests consist of two groups, with splices located either in the midspan region with a uniform bending moment, or in one of the end regions with a uniform shear force. The specimens were made of microconcrete with a maximum aggregate size 4.76 mm. Beams of three different heights (50, 100, and 200 mm) were tested. The beams were geometrically similar in three dimensions, and even the bar diameters and cover thicknesses were scaled in proportion. The reinforcement ratio was 0.31%. The results reveal the existence of a significant size effect, which can be approximately described by the size effect law previously proposed by Ba