Discussion of “Comparison of Roles of FRP Sheets, Stirrups, and Steel Fibers in Confining Bond Critical Regions” by Bilal S. Hamad and Ahmad A. Rteil

Abstract

Studies on confinement of tension lap splices and comparison of confinement provided by various techniques such as FRP wrapping, the use of fiber-reinforced concrete and the use of transverse steel have been very meticulously done by the authors. The authors are to be commended for their contribution to the understanding of bond performance with various levels of confinement. The discusser would like to highlight the effect of the size of the specimen on the results reported by the authors. The following points may be taken for discussion. 1. The length of the splice is fixed as 300 mm irrespective of the diameter of the bar. However, the amount of transverse reinforcement needed to provide adequate ductility depends on the splice length Azizinamani et al. 1999 . Because the length of the splice depends on the bar diameter, testing the confinement with a fixed splice length of 300 mm may not give the required results. 2. When the diameter of the bar being tested is varied, the size of the specimen tested must be proportional to the bar diameter Azizinamini et al. 1993 . In the investigations done by the authors, the depth of the beam is kept constant for all the specimens with different bar diameters. This makes the sec-