ASTM C97-15 pdf download.Standard Test Methods for Absorption and Bulk Specific Gravity of Dimension Stone.
5. Sampling
5.1 The sample shall be selected to represent a true average of the type or grade of stone under consideration and shall be ofthe quality supplied to the market under the type designation to be tested. The sample may be selected by the purchaser or his authorized representative from the quarried stone or taken from the natural ledge and shall be of adequate size to permit the preparation of at least five test specimens. When percep- tible variations occur, the purchaser may select as many samples as are necessary for determining the range in proper- ties. N OTE 1—Refer to Guide C1799 for additional information on selecting, preparing, and conditioning test specimens.
6. Test Specimens
6.1 The specimens may be cubes, prisms, cylinders, or any regular form with least dimension not under 2 in. [50 mm] and greatest dimension not over 3 in. [75 mm] but the ratio of volume to surface area shall not be less than 0.3 nor greater than 0.5 when measuring in inches [8 and 12.5 when measuring in millimetres]. All surfaces shall be reasonably smooth. Saw or core drill surfaces are considered satisfactory, but rougher surfaces shall be finished with No. 80 abrasive. No chisels or similar tools shall be used at any stage of preparing the specimens.
6.2 Prepare at least five specimens from each sample.
6.3 The same specimens may be used to determine both water absorption and bulk specific gravity. In this case, follow the procedures in 7.1 – 7.3 and 10.1, and issue a single report containing all information required in 9 and 13. Alternatively, separate specimens may be prepared from the same or different samples. In this case, follow the applicable procedure for separate determination and reporting of water absorption or bulk specific gravity, or both.
7. Procedure
7.1 Dry the specimens for 48 h in a ventilated oven at a temperature of 140 6 4°F [60 6 2°C]. At the 46th, 47th, and 48th hour, weigh the specimens to ensure that the weight is the same. If the weight continues to drop, continue to dry the specimens until there are three successive hourly readings with the same weight.ASTM C97 pdf download.