ASTM C31/C31M-18 pdf free.Standard Practice for Making and Curing Concrete Test Specimens in the Field.
This practice covers procedures for making and curing cylinder and beam specimens from representative samples of fresh concrete for a construction project.
4. Significance and Use
4.1 This practice provides standardized requirements for making. curing. protecting, and transporting concrete test specimens under field conditions.
4.2 If the specimens are made and standard cured, as stipulated herein, the resulting strength test data when the specimens are tested are able to be used for the following purposes:
4.2.1 Acceptance testing for specified strength,
4.2.2 Checking adequacy of mixture proportions for strength, and
4.2.3 Quality control.
4.3 If the specimens are made and field cured, as stipulated herein, the resulting strength test data when the specimens are tested are able to be used for the following purposes:
4.3.1 Determination of whether a structure is capable of being put in service,
4.3.2 Comparison with test results of standard cured spedmens or with test results from various in-place test methods.
4.3.3 Adequacy of curing and protection of concrete in the structure, or
4.3.4 Form or shoring removal time requirements.
5. Apparatus
5. 1 Molds. General—Molds for specimens or fastenings thereto in contact with the concrete shall he made of steel, cast iron, or other nonabsorbent material, nonreactive with concrete containing portland or other hydraulic cements. Molds shall hold their dimensions and shape under all conditions of use. Molds shall be watertight during use as judged by their ability to hold water poured into them. Provisions for tests of water leakage arc given in the Test Methods for Elongation. Absorption. and Water Leakage section of Specification C470/ C470M. A suitable sealant, such as heavy grease, modeling clay, or microcrystalline wax shall he used where necessary to prevent leakage through the joints. Positive means shall be provided to hold base plates Iirmly to the molds. Reusable molds shall be lightly coated with mineral oil or a suitable nonreactive form release material before use.
5.2 Cylinder Molds—Molds for casting concrete test specimens shall conform to the requirements of Specification C470/C470M.
7. Sampling Concrete
7.1 The samples used to fabricate test specimens under this standard shall be obtained in accordance with Practice C 172/ Cl72M unless an alternative procedure has been approved.
7.2 Record the identitication of the sample with respect to the location of the concrete represented and the time of casting.
8. Slump Air Content, and Temperature
8.1 Slump—Measure and record the slump of each batch of concrete from which specimens are made immediately after remixing in the receptacle, as required in Test Method C143/C143M.
8.2 Air C’onient—Dcteminc and record the air content in accordance with either Test Method C173/C173M or Test Method C23 1/C23 1M. The concrete used in performing the air content test shall not be used in fabricating test specimens.
8.3 Temperature—Determine and record the temperature in accordance with Test Method C10M/C10MM.ASTM C31/C31M-18 pdf free download.