ASTM C900-19 PDF Download

ASTM C900-19 standard provides guidelines for determining the pullout strength of hardened concrete. The test involves measuring the force required to pull an embedded metal insert and the attached concrete fragment from a concrete specimen or structure. The insert can either be cast into fresh concrete or installed in hardened concrete.

The standard emphasizes the importance of establishing strength relationships between pullout strengths and compressive strength test results. These relationships are influenced by factors such as the configuration of the embedded insert, bearing ring dimensions, depth of embedment, and the type of aggregate used. It is recommended to establish these relationships for each test system and concrete mixture by using specimens of similar size, density, and curing conditions.

The pullout test can be used to estimate the in-place strength of concrete, which is crucial for determining if it has reached a specified level of strength. This information is valuable in making decisions such as proceeding with post-tensioning, removing forms and shores, putting the structure into service, or terminating winter protection and curing. Post-installed pullout tests can also be employed to estimate the strength of concrete in existing construction.

Consideration should be given to the expected decrease in concrete strength with increasing height within a structural element when planning pullout tests and analyzing the results. The measured pullout strength represents the strength of concrete within the region defined by the insert head and bearing ring. In surface installations, the pullout strengths can indicate the quality of the outer zone of concrete members and aid in evaluating the cover zone of reinforced concrete members.

The test method is applicable to cast-in-place inserts that need to be planned in advance of concrete placement. However, for post-installed inserts, they can be placed at any desired location in the structure as long as the requirements specified in the standard are met. It is worth noting that this test method is not applicable to other types of post-installed tests that do not involve the same failure mechanism and do not produce the same conic frustum as described in the standard.