2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference

A Comparison of Plain and Deformed Hooked Bars in Concrete

Mr. Bjorn Vors, University of Saskatchewan
Dr. Lisa Feldman, University of Saskatchewan (Presenter)

Hooks are provided on reinforcing bars when the straight length between the bar and the point at which full development is required is insufficient to allow for the necessary force transfer with the surrounding concrete.  Hooks, when properly detailed, therefore enhance bar development and minimize bar slip, and are even more critical for the plain (i.e. undeformed) bars that were used reinforcement in Canada until about the mid-1950s.

An experimental investigation is therefore underway at the University of Saskatchewan to assess the effectiveness of hooked plain bars, as compared to modern deformed bars, in exterior beam-column joint specimens.  Both 90° and 180° hook geometries are being evaluated for both bar types.  Hook capacity, bar slip, and observations of the resulting failure modes are being recorded for all specimens.

This paper presents the experimental design of the overall program and presents the findings of the initial phase of specimen testing.