Book Description

Beams were designed to include two reinforcing bars in tension, spliced at the center of the span. The splice length was selected so that the bars would fail in bond, splitting the concrete cover in the splice region, before reaching the yield point. The bars were plain round Grade 60 bars with the splice length machined to simulate #6 (20 mm) deformed bars with parallel deformation pattern and different deformation geometries. No transverse reinforcement was provided in the splice region. The beam was loaded in positive bending and designed with constant moment region at the center of the beam. At each load increment, the deflection at the center of the beam was recorded and flexural cracks were marked and their widths measured. The variables were the bar rib face angle, rib spacing, and rib height. The results of this study were combined with results of previous investigations by Prof. Hamad to come up with recommendations concerning optimum rib geometries of deformed bars with superior bond-slip characteristics.