This method provides a means of obtaining compressive strength values from the same specimens previously used for flexural strength determinations by Test Method C 348. The compressive strength values are for reference purposes, and not as substitutes for values (using 50-mm (2-in.) cubes) obtained by Test Method C 109/C 109M for cement acceptance.³

1.1 This test method covers the determination of the compressive strength of hydraulic-cement mortars, using for the test specimens portions of prisms made and broken in flexure in accordance with Test Method C 348.

1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.

1.3 Values in SI units shall be obtained by measurement in SI units or by appropriate conversion, using the Rules for Conversion and rounding given in Standard IEEE/ASTM SI 10, of measurements made in other units.

1.4 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 and health 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.)