What does ASTM C578 specify?

ASTM C578 specifically outlines the specifications for rigid cellular polystyrene thermal insulation. This standard provides criteria for physical properties, manufacturing processes, and acceptable variations that ensure the insulation materials perform effectively in their intended applications, particularly in terms of thermal resistance and durability. By focusing on rigid cellular polystyrene, ASTM C578 addresses the unique characteristics of this type of insulation, making it a crucial resource for engineers, architects, and manufacturers looking to ensure that their insulation products comply with recognized standards.

The other options pertain to different materials and standards which do not relate to thermal insulation. For example, specifications for concrete mixes focus on the composition and qualities of concrete, while prestressing steel specifications deal with the requirements for steel used in construction for added strength. Specifications for aggregates refer to the standards concerning the materials that make up concrete mixtures. Each of these serves a different purpose in the construction and materials engineering fields, which clarifies why only the option regarding thermal insulation aligns with ASTM C578.