ASTM C172/C172M-14a pdf free.Standard Practice for Sampling Freshly Mixed Concrete.
1.1 This practice covers procedures for obtaining represen- tative samples of fresh concrete as delivered to the project site on which tests are to be performed to determine compliance with quality requirements of the specifications under which the concrete is furnished (Note 1)。 The practice includes sampling from stationary, paving and truck mixers, and from agitating and nonagitating equipment used to transport central-mixed concrete and from continuous mixing equipment as described in Specification 685/C685M.
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 may not be exact equivalents; therefore, each system shall be used independently of the other. Combinin values from the two systems may result in non-conformance with the standard.
1.3 This practice also covers the procedures to be used for
preparing a sample of concrete for further testing where it is desirable or necessary to remove the aggregate larger than a designated size. This removal of larger aggregate particles is preferably accomplished by wet-sievinG.
1.4 The text of this standard references notes and footnotes
which provide explanatory material and shall not be considered as requirements of the practice.
Significance and Use
3.1 This practice is intended to provide standard require- ments and procedures for sampling freshly mixed conerete from different containers used in the production or transporta tion of concrete. The detailed requirements as to materials. mixtures, air content, temperature, number of specimens. slump, interpretation of results, and precision and bias are in specific test methods.
4.1 The elapsed time shall not exceed 15 min. between Obtaining the first and final portions of the composite sample.
4. 1.1 Transport the individual samples to the place where fresh concrete tests are to be performed or where test speci- mens are to be molded. They shall be combined and remixed with a shovel the minimum amount necessary to ensure uniformity and compliance with the maximum time limits specified in 4.1.2.
4.1.2 Start tests for slump, temperature, and air content within 5 min after obtaining the final portion of the composite sample. Complete these tests expeditiously. Start molin specimens for strength tests within 15 min after fabricating the composite sample. Expeditiously obtain and use the sampl and protect the sample from the sun, wind, and other sources of apid evaporation, and from contamination.ASTM C172/C172M-14a pdf free download.