ASTM C109/C109M-21 Compressive Strength of Hydraulic Cement Mortars

Scope:

ASTM C109/C109M-21 test method determines the compressive strength of hydraulic cement and other mortars. This helps specify their application and determine their reliability. The results obtained from this method help in quality control, research, and performance evaluation of hydraulic apparatus.

Procedure:

In ASTM C109/C109M-21 the specimen mold is prepared as per the requirements. The mortar tested in this method consists of 1 part cement and 2.75 parts of sand proportioned by mass. Portland, air-entraining portland, portland-limestone, or air-entraining portland limestone cement are mixed at a specified water content. Water content for other cement is sufficient to obtain a flow of 110 ± 5 in 25 drops of the flow table. Two-inch or (50 mm) test cubes are compacted by tamping in two layers. The cubes are cured one day in the molds and stripped and immersed in lime water until tested.

Specimen Size:

Specimen size should be as per the requirements. In this case, the size of the specimen should be 2 inches or 50 mm.

Data:

The method covers the certification, sampling, testing, and inspection of the specimen within the set limits.  The compressive strength is determined by applying a formula where fm indicates compressive strength, P is the maximum load, and A is the area.

Conclusion:

ASTM C109/C109M-21 test method is specifically important for the quality assurance and compressive strength determination of hydraulic apparatus.