This specification covers the performance requirements for membrane-forming liquids suitable for use as curing compounds and sealers for fresh and hardened concrete. Each membrane should have good alkali resistance, acid resistance, adhesion-promoting qualities, and resistance to degradation by UV light. The materials are limited to clear or translucent and white pigmented materials, all of which are classified into non-yellowing, moderately yellowing, or yellows or darkens unrestrictedly.

1.1 This specification provides requirements for membrane-forming liquids suitable for use as curing compounds and sealers on freshly placed concrete and as sealers on hardened concrete. These membranes have special properties, such as, alkali resistance, acid resistance, adhesion-promoting qualities, and resistance to degradation by UV light.

Note 1: For liquid membrane-forming curing compounds specified primarily by their ability to retain water in newly placed concrete (and by drying time, and for white pigmented products, reflectance), see Specification C309.

1.2 This is a performance specification. The allowable composition of products covered by this specification is limited by various local, regional, and national regulations. Issues related to air quality (solvent emission), worker exposure, and other hazards are not addressed here. It is the responsibility of the producers and users of these materials to comply with pertinent regulations.

Warning—Some VOC exempt solvents used to meet the regulations are extremely flammable with low auto ignition temperatures and rapid evaporation rates. Consult the manufacturer's product information sheet for important application and safety information.

1.3 The values stated in SI units are to be regarded as the standard. (Inch pound units are shown in parentheses).

1.4 The following precautionary caveat pertains only to the test methods portion, Section 9, of this specification. 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.