The Magnesium Sulfate Soundness Hydrometer measures specific gravity of sulfate solution to ±0.001 SG.
Soundness testing of aggregate requires repeated immersion cycles in sodium sulfate or magnesium sulfate solution, followed by drying. Rehydration of the salts simulates expansion of freezing water. Samples are then washed, dried and sieved to determine percentage of loss from original sample.
Sample Sieves holding aggregate specimens are stacked into Sieve Holders. The Holders are then immersed in Solution Buckets containing sulfate solution. The Refrigerated Circulator and Water Bath Tank need only be used if the temperature of the sulfate solution cannot be maintained at the specified 70°F (21°C).
Meets Test Methods:
ASTM C 88