1.1 This test method covers a procedure for making and curing concrete specimens and for testing them at an early age. The specimens are stored under standard or accelerated curing conditions and the measured temperature history is used to compute a maturity index that is related to strength gain.
1.2 This test method also covers a procedure for using the results of early-age compressive-strength tests to project the potential strength of concrete at later ages.
1.3 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.
1.4 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of 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 skin and tissue upon prolonged exposure.)2
1.6 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.
ASTM C918/C918M-20 Referenced Document
ASTM C1074 Standard Practice for Estimating Concrete Strength by the Maturity Method
ASTM C1231/C1231M Standard Practice for Use of Unbonded Caps in Determination of Compressive Strength of Hardened Cylindrical Concrete Specimens*, 2023-10-20 Update
ASTM C125 Standard Terminology Relating to Concrete and Concrete Aggregates*, 2021-10-01 Update
ASTM C1768/C1768M Standard Practice for Accelerated Curing of Concrete Cylinders
ASTM C192/C192M Standard Practice for Making and Curing Concrete Test Specimens in the Laboratory
ASTM C31/C31M Standard Practice for Making and Curing Concrete Test Specimens in the Field*, 2024-04-01 Update
ASTM C39/C39M Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
ASTM C470/C470M Standard Specification for Molds for Forming Concrete Test Cylinders Vertically
ASTM C617/C617M Standard Practice for Capping Cylindrical Concrete Specimens*, 2023-10-20 Update
ASTM C670 Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
ASTM C918/C918M-20 history
2020ASTM C918/C918M-20 Standard Test Method for Measuring Early-Age Compressive Strength and Projecting Later-Age Strength
2013ASTM C918/C918M-13 Standard Test Method for Measuring Early-Age Compressive Strength and Projecting Later-Age Strength
2007ASTM C918/C918M-07 Standard Test Method for Measuring Early-Age Compressive Strength and Projecting Later-Age Strength
2002ASTM C918-02 Standard Test Method for Measuring Early-Age Compressive Strength and Projecting Later-Age Strength
1997ASTM C918-97e1 Standard Test Method for Measuring Early-Age Compressive Strength and Projecting Later-Age Strength