ASTM C39/C39M-21 PDF Download

The ASTM C39/C39M-21 standard is a test method used to determine the compressive strength of cylindrical concrete specimens, including molded cylinders and drilled cores. It is important to exercise caution when interpreting the results of this test method, as compressive strength is not an intrinsic property of concrete but depends on various factors such as specimen size and shape, batching and mixing procedures, sampling methods, curing conditions, and more.

This test method is used to evaluate the compressive strength of concrete specimens prepared and cured in accordance with various practices and test methods specified in the standard. The results obtained from this test are commonly used for quality control purposes, including assessing compliance with specifications, evaluating the effectiveness of admixtures, and controlling concrete proportioning, mixing, and placing operations.

It is important to note that individuals conducting the testing for acceptance purposes must meet the concrete laboratory technician requirements outlined in Practice C1077. This may include certification equivalent to the minimum guidelines for ACI Concrete Laboratory Technician, Level I or ACI Concrete Strength Testing Technician, which are evaluated by an independent examiner.

The standard includes notes that provide additional explanatory material, but these notes are not considered requirements of the standard itself. The test method is specifically applicable to concrete with a density exceeding 800 kg/m³ [50 lb/ft³].