ASTM C1218/C1218M-20

4.1 Water-soluble chloride, if present in sufficient amount, is capable of initiating or accelerating the corrosion of some metallic materials embedded in or contacting cementitious mixtures such as mortar and concrete. Chloride content, along with other factors, can be indicators for the possibility of corrosion of embedded metallic materials. This test method is used to determine the water-soluble chloride content in cementitious mixtures, either in new construction or existing structures.

4.2 Sulfides are known to interfere with the determination of chloride content. Blast-furnace slag aggregates and cements contain sulfide sulfur in concentrations that are capable of such interference and produce erroneously high test results. Treatment with hydrogen peroxide, as discussed in Test Methods C114, is used to eliminate such interference.

4.3 There are aggregates that contain chloride that is not available for corrosion. Such chloride will be detected by use of this test method.3

1.1 This test method provides procedures for the sampling and analysis of hydraulic-cement mortar or concrete for chloride that is water soluble under the conditions of test.

1.2 The text of this standard references notes and footnotes that provide explanatory information. These notes and footnotes shall not be considered as requirements of this standard.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as a standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.