ASTM C88/C88M-18 PDF Download

The ASTM C88/C88M-18 standard is titled "Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate". This test method is used to estimate the soundness of aggregates for use in concrete and other applications by subjecting them to weathering action. It involves immersing the aggregates in saturated solutions of sodium or magnesium sulfate and then drying them to remove the salt precipitated in permeable pore spaces. Upon re-immersion, the rehydration of the salt creates an internal expansive force that simulates the expansion of water on freezing. This test method provides information on the soundness of aggregates in the absence of service records of exposure to actual weathering conditions.

The standard highlights the fact that the precision of this test method is poor and therefore it may not be suitable for outright rejection of aggregates without confirmation from other tests. It also mentions that the permitted-loss percentage values obtained from this test method are usually different for fine and coarse aggregates. It cautions that test results using sodium sulfate and magnesium sulfate differ considerably, and careful consideration is needed when setting proper limits in specifications that include requirements for these tests. Limits for percent loss allowed are normally higher when magnesium sulfate is used.

The standard also provides information on the units of measurement. It states that the values can be reported in either SI (International System of Units) or inch-pound units, with the inch-pound units shown in brackets. The values are not exact equivalents, so each system should be used independently. If results obtained from another standard are reported in a different system of units, conversion factors from the SI Quick Reference Guide can be used.