ASTM C109/C109M-13e1 pdf free.Standard Test Method for Compressive Strength of Hydraulic Cement Mortars.
3. Summary of Test Method
3.1 The mortar used consists of I part cement and 2.75 parts of sand proportioned by mass. Portland or air-entraining portland cements are mixed at specified water/cement ratios. Water content for other cements is that sufficient to obtain a flow of 110 ± 5 in 25 drops of the flow table. Two-inch or 150-mini test cubes are compacted by taniping in two layers.
The cubes are cured one day in the molds and stripped and immersed in lime water until tested.
4. Significance and Use
4.1 ASTM C109 provides a means of determining the compressive strength of hydraulic cement and other mortars and results may be used to determine compliance with specifications. Further, this test method is referenced by numerous other specifications and test methods. Caution must be exercised in using the results of this test method to predict the strength of concretes.
5. Apparatus
5. 1 Weighis and Weighing Devices, shall conform to the requirements of Specification C1005. The weighing device shall he evaluated for precision and accuracy at a total load ot 2000 g.
9. Preparation of Specimen Molds
9.1 Apply a thin coating of release agent to the inicrior faces of the mold and non-absorptive base plates. Apply oils and greases using an impregnated cloth or other suitable means. Wipe the mold faces and the base plate with a cloth as necessary to remove any excess release agent and to achieve a thin, even coating on the interior surfaces. When using an aerosol lubricant, spray the release agent directly onto the mold faces and base plate from a distance of 6 to 8 in. or [150 to 200 mm] to achieve complete coverage. After spraying. wipe the surface with a cloth as necessary to remove any excess aerosol lubricant. The residue coating should be just sufficient to allow a distinct finger print to remain following light linger pressure (Note 5).
9.2 Seal the surfaces where the halves of the mold join by applying a coating of light cup grease such as petrolatum. The amount should be sufficient to extrude slightly when the two halves are tightened together. Remove any excess grease with a cloth.