Recently, the ASTM committee changed the F1869 Calcium Chloride standard to specifically disallow Calcium Chloride testing for all lightweight aggregate concrete.
Going as far back as the 1940s, Calcium Chloride testing has been used to determine the suitable moisture content of poured concrete slabs when applying resilient floor coverings. The standard for performing the Calcium Chloride test has seen many changes over the years, but both the science supporting Calcium Chloride as a test method and the reliability of the test method have remained problematic. Since 2002, ASTM-F2170 In-Situ Relative Humidity testing has been replacing Calcium Chloride as the preferred method for concrete moisture determination.
ASTM changes F1869 testing protocol
November 17, 2010