Which ASTM standard specifies sheet materials used for curing concrete?

The correct answer, ASTM C171, specifies the requirements for sheet materials used for curing concrete. Proper curing of concrete is essential for ensuring that it achieves its desired strength and durability, and the standard outlines the performance characteristics, such as moisture retention and temperature control, which are critical for effective curing. ASTM C171 provides guidelines on the types of materials that can be used, ensuring they contribute positively to the curing process by retaining moisture for the required duration while also being durable enough to withstand environmental conditions.

The other standards listed focus on different aspects of concrete and construction materials. ASTM C494, for example, pertains to chemical admixtures for concrete, while ASTM C1621 deals with the performance of self-consolidating concrete. ASTM C979 relates to the color of concrete by specifying the use of pigments. Each of these standards serves a specific purpose in the broader context of construction and concrete work, but ASTM C171 uniquely addresses the crucial aspect of curing concrete effectively through the use of appropriate sheet materials.