1.1 This test method determines the quasi-static ultimate strength of fiber-reinforced polymer (FRP) composite bent bars commonly used as anchorages for stirrups in reinforced, prestressed, or post-tensioned concrete structures. This test method only applies to bars with a solid cross section. 1.2 FRP bent bars are often used in reinforced concrete applications to shorten the development length of the bar or act as a tie or a stirrup to resist shear forces. Bent bars can be produced with varying angles of bend to fit their intended purpose. 1.3 For this test method, the FRP bars are bent at a 90 angle. In general, bars have a regular pattern of surface undulations or a coating of bonded particles or both that promote mechanical interlock between the bar and concrete. 1.4 The strength values provided by this test method are short-term quasi-static strengths that do not account for sustained static or cyclic loading. Additional material characterization may be required, especially for bars that are to be used under high levels of sustained or repeated loading. 1.5 The characteristic values obtained from this test method are intended to represent the quasi-static ultimate strength of FRP bent bars with a tail length of twelve bar diameters. 1.6 The values stated in either SI or inch-pound units shall be regarded separately as the standard. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of each other. Combining values from the two systems may result in nonconformance with the standard. 1.6.1 Within the text, the inch-pound units are shown in brackets. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Need to transition American Concrete Institute Test Method B.5 to ASTM D30 per agreement between ACI and ASTM.
Keywordsbend strength; fiber-reinforced polymer; FRP; stirrup; bent bar; concrete reinforcement
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top