ASTM C1152

Acid-Soluble Chloride in Mortar and Concrete

Applicability: Applies to fresh and hardened mortar and concrete, including samples taken during construction, from existing structures, or from laboratory-prepared specimens. Used to assess chloride content as a risk indicator for reinforcement corrosion in reinforced and prestressed concrete structures, particularly in marine environments, bridge decks, parking structures, and other applications where chloride exposure is a durability concern.

Purpose: Determines the acid-soluble chloride ion content of mortar and concrete samples by dissolving a powdered sample in nitric acid and quantifying chloride by potentiometric titration with silver nitrate. Acid-soluble chloride represents the fraction of total chloride that is available to participate in corrosion reactions at the steel reinforcement surface. Results are compared against threshold limits in ACI 318 and other structural design standards to evaluate corrosion risk and inform decisions regarding concrete mix design, protective coatings, or remediation.