The amount of acid-soluble chloride in most hydraulic-cement systems is equal to the total amount of chloride in the system. However, some organic substances that may be introduced into mortar or concrete contain chloride that is initially acid-insoluble that can eventually ionize and thus become acid-soluble or water-soluble after a period of exposure in the very alkaline cement system. Sulfides are known to interfere with the determination of chloride content. Blast-furnace slag aggregates and cements contain sulfide sulfur in concentrations that can cause such interference and produce erroneously high test results. Treatment with hydrogen peroxide is used to eliminate such interference. There are aggregates that contain chloride that is not available for corrosion. Such chloride will be detected by the use of this method.
KeywordsChloride Content - Concrete - Hydraulic Cement - Inorganic Matter Content - Mortars
ICS CODE91.100.10 (Cement. Gypsum. Lime. Mortar.); 91.100.30 (Concrete and concrete products)
UNSPSC CODE30111504 (Mortars); 30111500 (Concrete and mortars)
ASTM C1152 / C1152M-04(2012)e1, Standard Test Method for Acid-Soluble Chloride in Mortar and Concrete, ASTM International, West Conshohocken, PA, 2012, www.astm.org