This Standard sets out the method for determining the air content of freshly mixed concrete from observations of the change in volume of the concrete when it is subjected to an increased air pressure (see Note 1).The method provides for compaction of the sample either by rodding or by vibration (see Note 2).NOTES: 1 This method is intended for use with concretes made with relatively dense natural aggregates for which the aggregate correction factor can be determined satisfactorily by the technique described in Clause 10. It is not recommended for use with concretes made with lightweight aggregates, or aggregates of high porosity (see AS 1012.4.3).2 The results obtained will be dependent on the compaction method used.3 This Standard may involve hazardous materials, operations, and equipment. The Standard does not purport to address all of the safety problems associated with its use. The user of this Standard should establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.4 Data on the precision of the test method were not available at the time of publication. This information will be included when available.

First published as part of AS A109-1957.Second edition 1972.Revised and redesignated AS 1012.4-1972.AS A109-1972 withdrawn 1976.Second edition AS 1012.4-1983.Revised and redesignated in part as AS 1012.4.1-1999. First published as part of AS A109-1957. Second edition 1972. Revised and redesignated AS 1012.4-1972. AS A109-1972 withdrawn 1976. Second edition AS 1012.4-1983. Revised and redesignated in part as AS 1012.4.1-1999.