ASTM D7914/D7914M-14
Standard Test Method for Strength of Fiber Reinforced Polymer (FRP) Bent Bars in Bend Locations

Standard No.

ASTM D7914/D7914M-14

Release Date

2014

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM D7914/D7914M-21

Latest

ASTM D7914/D7914M-21

Scope

5.1 This test method is intended to determine the bend strength developed at a standard twelve bar diameters of embedment and the strength reduction factors of FRP bent bars that are typically used as anchorages in concrete. From this test, a variety of data are acquired that are needed for design purposes. Material-related factors that influence the tensile response of bars and should therefore be reported include the following: constituent materials, void content, volume percent reinforcement, methods of fabrication, and fiber reinforcement architecture. Similarly, factors relevant to the measured tensile response of bars include specimen preparation, specimen conditioning, environment of testing, specimen alignment, and speed of testing. Properties, in the test direction, that may be obtained from this test method include:

5.1.1 Ultimate bend strength of the FRP bent bar and

5.1.2 Percentage of the guaranteed tensile strength of the straight portion of the bar that is retained in the bend location.

5.2 The results may be used for material specifications, research and development, and structural design and analysis.

Note 1: Two FRP bends are tested simultaneously in this test method, but in some cases only one bend may rupture. While resulting in a valid failure, notice should be taken that only one bend has been effectively measured and that the final compiled test results using this method could differ from those resulting from single FRP bend testing.

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 to act as a tie or a stirrup to resist shear forces. Bent bars can be produced with varying angles of bend in order to fit their intended purpose.

1.3 For this test method, the FRP bars are bent at a 90 degree angle. In general, bars have a regular pattern of surface undulations, a coating of bonded particles, or both, that promote mechanical interlock between the bar and concrete.

1.4 The strength values provided by this method are short-term, quasi-static tensile strengths that do not account for sustained static or cyclic loading. If bars are to be used under high levels of sustained or repeated loading, additional material characterization may be required.

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 units or inch-pound units are to b......

ASTM D7914/D7914M-14 Referenced Document

• ASTM A615/A615M Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement
• ASTM C143/C143M Standard Test Method for Slump of Hydraulic-Cement Concrete
• ASTM C192/C192M Standard Practice for Making and Curing Concrete Test Specimens in the Laboratory
• ASTM C39/C39M Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• ASTM D3171 Standard Test Methods for Constituent Content of Composite Materials
• ASTM D3878 Standard Terminology Composite Materials
• ASTM D5229/D5229M Standard Test Method for Moisture Absorption Properties and Equilibrium Conditioning of Polymer Matrix Composite Materials
• ASTM D7205/D7205M Standard Test Method for Tensile Properties of Fiber Reinforced Polymer Matrix Composite Bars
• ASTM D792 Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
• ASTM D883 Standard Terminology Relating to Plastics
• ASTM E122 Standard Practice for Calculating Sample Size to Estimate, With a Specified Tolerable Error, the Average for Characteristic of a Lot or Process
• ASTM E4 Standard Practices for Force Verification of Testing Machines
• ASTM E456 Standard Terminology for Relating to Quality and Statistics
• ASTM E6 Standard Terminology Relating to Methods of Mechanical Testing

ASTM D7914/D7914M-14 history

• 2021 ASTM D7914/D7914M-21 Standard Test Method for Strength of Fiber Reinforced Polymer (FRP) Bent Bars in Bend Locations
• 2014 ASTM D7914/D7914M-14 Standard Test Method for Strength of Fiber Reinforced Polymer (FRP) Bent Bars in Bend Locations