ASTM C88-2018 pdf free download
ASTM C88-2018 pdf free download.Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate
1. Scope
1.1 This test method covers the testing of aggregates to estimate their soundness when subjected to weathering action in concrete or other applications. This is accomplished by repeated immersion in saturated solutions of sodium or mag- nesium sulfate followed by oven drying to partially or com- pletely dehydrate the salt precipitated in permeable pore spaces. The internal expansive force, derived from the rehy- dration of the salt upon re-immersion, simulates the expansion of water on freezing. This test method furnishes information helpful in judging the soundness of aggregates when adequate information is not available from service records of the material exposed to actual weathering conditions. 1.2 The values stated in SI or inch pound units shall be regarded separately as standard. The inch –pound units are shown in brackets. The values stated are not exact equivalents; therefore each system shall be used independently of the other. Combining values from the two systems may result in noncon- formance. 1.3 Some values have only SI units because the inch-pound equivalents are not used in practice. 1.4 If the results obtained from another standard are not reported in the same system of units as used by this test method, it is permitted to convert those results using the conversion factors found in the SI Quick Reference Guide. N OTE 1—Sieve size is identified by its standard designation in Speci- fication E11. The alternate designation given in parentheses is for information only and does not represent a different standard sieve size. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.20 on Aggregates.
6. Special Solutions Required
6.1 Prepare the solution for immersion of test samples from either sodium or magnesium sulfate in accordance with 6.1.1 or 6.1.2 (Note 4). The volume of the solution shall be at least five times the solid volume of all samples immersed at any one time. NoTE 4- Some aggregates containing carbonates of calcium or mag- nesium are attacked chemically by fresh sulfate solution, resulting in erroneously high measured losses. If this condition is encountered or is suspected，repeat the test using a filtered solution that has been used previously to test the same type of carbonate rock， provided that the solution meets the requirements of 6.1.1 and 6.1.2 for specific gravity. 6.1.1 Sodium Sulfate Solution- Prepare a saturated solution of sodium sulfate by dissolving a USP or equal grade of the salt in water at a temperature of 25 to 30 °C (77 to 86 °F). Add sufficient salt (Note 5), of either the anhydrous (Na2SO4) or the crystalline (Na2 SO4. 10H2O) form,” to ensure not only satura- tion but also the presence of excess crystals when the solution is ready for use in the tests. Thoroughly stir the mixture during the addition of the salt and stir the solution at frequent intervals until used. To reduce evaporation and prevent contamination, keep the solution covered at all times when access is not needed. Allow the solution to cool to 21 6 1 °C (70 6 2 °F). Again stir, and allow the solution to remain at the designated temperature for at least 48 h before use. Prior to each use, break up the salt cake， if any, in the container， stir the solution thoroughly, and determine the specific gravity of the solution. When used, the solution shall have a specific gravity not less than 1.151 nor more than 1.1 74. Discard a discolored solution, or filter it and check for specific gravity.
