ASTM C1857/C1857M-19

5.1 When the test is performed on the repair or overlay material, the result is the bond strength to the concrete panel or the tensile strength of either the overlay or concrete panel, whichever is weaker.

5.2 The measured strength is controlled by the failure mechanism requiring the least stress. Thus, it is not possible to know beforehand which strength will be measured by the test. For this reason, the failure mode has to be reported for each individual test result, and tests results are averaged only if the same failure mode occurs. Alternatively, one can infer that the bond strength is greater than the failure stress if the bond does not fail during the test.

5.3 The method may also be used to evaluate the performance of bonding agents.

5.4 This test method is designed to evaluate bond strengths in the laboratory and to standardize conditions that permit comparison of results between laboratories. It is not intended to determine bond strength for field applications as results obtained are only applicable to the standard substrate.

1.1 This test method is suitable for laboratory use to determine one or more of the following:

1.2 The 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. Some values have only SI units because the inch-pound equivalents are not used in practice.