ASTM C309-19 PDF Download

ASTM C309-19 is a standard specification that covers liquid membrane-forming compounds used for curing concrete surfaces. The purpose of these compounds is to reduce the loss of water during the early-hardening period of concrete. The standard specifies that clear or translucent liquid membrane-forming compounds should be used for Type 1 and 1-D applications. On the other hand, Type 2 compounds should consist of finely-divided white pigment and vehicle, ready-mixed for immediate use.

The white-pigmented membrane-forming compounds covered in this specification have the additional benefit of reducing the temperature rise in concrete exposed to sunlight radiation. These compounds can be used as curing media for fresh concrete and can also be applied for further curing after removal of forms or initial moist curing. The standard establishes requirements for water loss restriction, daylight reflectance, and drying time.

It is important to note that this specification only addresses certain properties, and compounds with special properties such as better water retention, resistance to UV radiation, and non-interference with adhesives are covered in Specification C1315. This standard is a performance specification and does not cover issues related to air quality, worker exposure, and other hazards. It is the responsibility of producers and users to comply with relevant regulations.

The standard includes warnings about extremely flammable VOC exempt solvents that may be used in these compounds and emphasizes the need to consult the manufacturer's product information sheet for important application and safety information. Notes and footnotes in the standard provide explanatory material but are not considered requirements.