Though appropriate for its time, the Standard Test Method for Water Loss Through Liquid Membrane-Forming Curing Compounds for Concrete – or ASTM C309 – was developed when finishing techniques had not yet progressed to the effectiveness of contemporary practices. Wood float finishes, as required by ASTM C309 in accordance with ASTM C156, create a more porous surface than steel-bladed power trowel techniques commonly used today. Steel troweled finishes result in a harder, tighter surface that reduces moisture loss, aiding cement hydration.
The Standard for measuring the effectiveness of curing compounds has historically been ASTM C 309, “Standard Specification for Liquid Membrane-Forming Compounds for Curing Concrete.” The test procedure for this specification measures the moisture loss of a test specimen that has a wood float finish and utilizes a liquid membrane-forming compound. While this Standard has proven to be an effective measure to gage acceptable curing products for concrete, developments in the placement/finish of concrete and advancing technologies of concrete chemicals have paved the way for innovative perspectives on curing of concrete, particularly as it pertains to industrial floors.