ASTM C31/C31M-19a - 15.12.2019
 
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 specimens 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.

 
1. 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 The concrete used to make the molded specimens shall be sampled after all on-site adjustments have been made to the mixture proportions, including the addition of mix water and admixtures. This practice is not intended for making specimens from concrete not having measurable slump or requiring other sizes or shapes of specimens.

1.3 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.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to exposed skin and tissue upon prolonged exposure.2)

1.6 The text of this standard references notes which provide explanatory material. These notes shall not be considered as requirements of the standard.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

 
2. Referenced Documents

C231/C231M-26

Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method

C330/C330M-23

Standard Specification for Lightweight Aggregates for Structural Concrete

C1077-26a

Standard Practice for Agencies Testing Concrete and Concrete Aggregates for Use in Construction and Criteria for Testing Agency Evaluation (Includes all amendments and changes 8/17/2026).

C403/C403M-23

Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance

C511-21

Standard Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic Cements and Concretes

C617/C617M-23

Standard Practice for Capping Cylindrical Concrete Specimens

C1064/C1064M-23

Standard Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete

C470/C470M-23

Standard Specification for Molds for Forming Concrete Test Cylinders Vertically

309R

Guide for Consolidation of Concrete

C125-26

Standard Terminology Relating to Concrete and Concrete Aggregates

C138/C138M-24a

Standard Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete (Includes all amendments and changes 8/6/2024).

C143/C143M-26b

Standard Test Method for Slump of Concrete (Includes all amendments and changes 8/6/2026).

C172/C172M-25

Standard Practice for Sampling Freshly Mixed Concrete

C173/C173M-26

Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method