This method covers the determination of compressive strength of concrete, using portions of beams broken in flexure for test specimens.

Note 1 - This method was originally developed to cover testing portions of beams having a square cross section as "modified cubes" and former versions of this procedure were subtitled "Modified Cube Method." This terminology no longer applies because beams of rectangular cross section may be tested as provided under Section 6.1.

Note 2 - For methods of making flexural test specimens from which the specimens for this test method may be obtained, refer to R 39, T 23, and T 24M/T 24.