Hysteretic Behavior of Reinforced Concrete Flexural Members with Special Web Reinforcement,

摘要

This report describes cyclic loading experiments with two reinforced concrete beams having special web reinforcement in the critical regions. The analysis of the effectiveness of the special reinforcement on the hysteretic behavior of these members when subjected to high shear reversals receives the main emphasis. Two 78in. long cantilever beams with 15 x 29in. cross sections and reinforced both top and bottom with six No. 9deformed bars were tested using two different types of web reinforcement. For each of the beams the web reinforcement was designed to resist the full maximum shear force. In one of the beams the web reinforcement consisted of double stirrup-ties which were able to offer by means of their corners good lateral supports to all the main longitudinal bars. In addition,two longitudinal bars were added at mid-depth of the beam,and along its critical region supplementary cross ties were also provided. In this manner an excellent basketing of the concrete in the critical region was achieved. The web reinforcement of the second beam consisted of intersecting 45degrees inclined struts,each fabricated from four No. 6bars assembled together into a rigid cage by means of ties. Detailed descriptions of the specimens,testing procedure,experimental data and results obtained are presented. (Modified author abstract)