Ductility demand of compression yielding fiber-reinforced polymer-reinforced concrete beams

The ductility of fiber-reinforced polymer (FRP) reinforced concrete (RC) members has been a major concern. Although significant efforts have been made in this research area, a general and effective way of increasing ductility has not been found. A new structural scheme of providing ductility to RC numbers through the compressive yielding (CY) instead of the tensile yielding has recently been developed by the author. The CY beams rely on the compressive deformation of the plastic hinge to achieve ductility. Therefore, adequate ductility of the RC members can be achieved without ductility demand on the tensile reinforcement. Because ductility of the CY beams comesfrom a small CY zone, the ductility demand on the material is excessive, which cannot be achieved by using conventional construction materials or structural measures. To study the ductility demand of the CY zone for the design of the CY beams, basic theory that relates the ductility demand of the CY zone to the design ductility of the member is developed in this work. A very effective CY mechanism of perforated block (P-block) that can satisfy the ductility demand of the CY zone is also developed and introduced. Copyright © 2008, American Concrete Institute. All rights reserved.