ASTM D8337/D8337M-21

5.1?This test method is intended for use in a laboratory setting.

5.2?This test method is used to evaluate the plateau force P_pl that an FRP composite can bear before complete debonding from a concrete prism.

5.3?The evaluation of the plateau force is intended to be made under consistent environmental conditioning and the tests conducted in ambient laboratory or otherwise consistent environmental conditions.

5.4?This test can be used to determine the effective bond length 5.5?This test can be used to determine the variation of the bond capacity with the bonded width b_f if different bonded widths are tested while the bonded length is constant and greater than the effective bond length l_eff.

5.6?This test is used to obtain the plot of the applied force versus loaded end (or global) slip of the composite with respect to the substrate. The loaded end slip is the average of two linear variable differential transformer (LVDT) readings, as described in 7.6. The plot obtained is used to determine the bond properties of the system.

5.7?This test method can also serve as a means for uniformly preparing and testing standard specimens suitable for being subject to environmental conditioning and subsequently used to evaluate FRP-bonded-to-concrete system performance, and evaluating and reporting the results. The comparison of results from this test method conducted on identical specimens subject to different environmental conditioning protocols can be used to evaluate the effects of environmental exposure on the bond performance of FRP systems.

1.1?This test method describes the apparatus and procedure to evaluate the lap shear bond properties of wet lay-up or shop-fabricated (for example, pultruded) fiber-reinforced polymer (FRP) composite systems adhesively applied to a flat concrete substrate. The test determines the plateau force that an FRP system can bear before complete debonding from a concrete prism tested using a direct single-lap shear test. This plateau force is reported as bond capacity and may be different from the maximum applied force. The plateau force is then used to determine the interfacial fracture energy and the cohesive material law.

1.2?This test method is not intended for job approval or for product qualification purposes unless an external agency adopts the test method for those purposes.

1.3?This test method is intended for use with adhesive-applied or wet lay-up FRP systems and is appropriate for use with FRP systems having any ?ber orientation or combination of ply orientations comprising the FRP composite, although the test condition only considers forces in the direction parallel to the prism longitudinal axis.

1.4?UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.5?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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.