If you are currently using the D4546-14 (or older) PDF, be aware that the update introduced significant clarifications. The ASTM committee (D18 on Soil and Rock) focused heavily on strain-controlled procedures .
: Updated formulas for calculating percent swell and swell pressure to reduce interpretation errors.
Purchase the official ASTM D4546-21 PDF today to ensure your geotechnical data is defensible in court and accurate in the field.
The percentage of expansion that occurs under a very low nominal pressure (