ASTM C143/C143M-20 PDF Download

The ASTM C143/C143M-20 standard is a test method used to determine the slump of hydraulic-cement concrete. The purpose of this test method is to provide users with a procedure to measure the consistency of plastic concrete. This test method was originally developed to monitor the consistency of unhardened concrete, but it is important to note that the relationship between slump and concrete strength may vary under field conditions. Therefore, caution should be exercised when relating slump results obtained in the field to concrete strength.

This test method is applicable to plastic concrete containing coarse aggregate up to 1.5 inches (37.5 mm) in size. If the coarse aggregate is larger than 1.5 inches (37.5 mm), the test method can still be applied by performing the test on the fraction of concrete that passes a 1.5-inch (37.5 mm) sieve, with the larger aggregate being removed.

However, it is important to note that this test method is not suitable for non-plastic and non-cohesive concrete. Concretes with slumps less than 0.5 inches (15 mm) may not be sufficiently plastic, and concretes with slumps greater than 9 inches (230 mm) may not have sufficient cohesion for this test to have significance. Therefore, interpretation of results should be done with caution in such cases.