ASTM C900-15 pdf free download.Standard Test Method for Pullout Strength of Hardened Concrete.
ASTM C900-15 method covers determination of the pullout strength of hardened concrete by measuring the force required to pull an embedded metal insert and the attached concrete fragment from a concrete test specimen or structure. The insert is either cast into fresh concrete or installed in hardened concrete.
ASTM C900-15 does not provide statistical procedures to estimate other strength properties.
4. Summary of Test Method
4.1 A metal insert is either cast into fresh concrete or installed into hardened concrete. When a measure of the in-place pullout strength is desired, the insert is pulled by means of a jack reacting against a bearing ring. The pullout strength is determined by measuring the maximum force required to pull the insert from the concrete mass. Alternatively, the insert is loaded to a specified load to verify whether a minimum level of in-place pullout strength has been attained.
5. Significance and Use
5.1 For a given concrete and a given test apparatus. pullout strengths can be related to compressive strength test results. Such strength relationships are affected by the configuration of the embedded insert, bearing ring dimensions, depth of embedment, and the type of aggregate (lightweight or normal weight). Before use, the relationships must be established for each test system and each new concrete mixture. Such relationships are more reliable if both pullout test specimens and compressive strength test specimens arc of similar size, consolidatcd to similar density, and cured under similar conditions.
In addition, post-installed pullout tests may be used to estimate the strength of concrete in existing construction.
5.3 When planning pullout tests and analyzing test results, consideration should be given to the normally expected decrease of concrete strength with increasing height within a given concrete placement in a structural element.
5.4 The measured pullout strength is indicative of the strength of concrete within the region represented by the conic frustum defined by the insert head and bearing ring. For typical surface installations, pullout strengths are indicative of the quality of the outer zone of concrete members and can be of benefit in evaluating the cover zone of reinforced concrete members.
5.5 Cast-in-place inserts require that their locations in the structure he planned in advance of concrete placement. Postinstalled inserts can he placed at any desired location in the structure provided the requirements of 7.1 are satisfied.
5.6 This test method is not applicable to other types of post-installed tests that, if tested to failure, do not involve the same failure mechanism and do not produce the same conic frustum as for the cast-in-place test described in this test method (16).