ASTM C31 – Standard Practice for Making and Curing Concrete Test Specimens in the Field
Description:
Significance and Use
4.1 This practice provides standardized requirements for making, and curing test specimens in the field. This practice also provides requirements for transporting test specimens to the laboratory, and for curing test specimens in the laboratory. Depending on their purpose, test specimens are either standard-cured, or field-cured.
4.2 Uses of the test results of standard-cured test specimens include the following purposes:
4.2.1 Acceptance testing for specified concrete strength,
NOTE 2: Specification C94/C94M requires compressive-strength test specimens for acceptance to be standard-cured.
4.2.2 Checking adequacy of mixture proportions for concrete strength, and
4.2.3 Quality control.
4.3 Uses of test results of field-cured test specimens include:
4.3.1 Estimation of the in place concrete strength,
4.3.2 Comparison with test results of standard cured specimens or with test results from various in-place test methods,
4.3.3 Adequacy of curing and protection of concrete in the structure,
4.3.4 Form or shoring removal time requirements, or
4.3.5 Post-tensioning.
Scope
1.1 This practice covers procedures for making and curing cylinder and beam specimens from representative samples of fresh concrete for a construction project.
1.2 This practice is not intended for making specimens from concrete not having measurable slump or requiring other sizes or shapes of specimens.
1.3 This practice is not applicable to lightweight insulating concrete or controlled low strength material (CLSM).
NOTE 1: Test Method C495/C495M covers the preparation of specimens and the determination of the compressive strength of lightweight insulating concrete. Test Method D4832 covers procedures for the preparation, curing, transporting and testing of cylindrical test specimens of CLSM.
1.4 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. Combining values from the two systems may result in non-conformance with the standard.
ASTM C308