Answer :
Final answer:
The question asks about the standard to which measures other than air meter bowls used for concrete air content tests must conform. The correct standard is ASTM C231, which concerns the pressure method for determining air content in freshly mixed concrete. This standard is critical for quality and durability in concrete construction. Therefore the correct answer is b).
Explanation:
The ASTM C231 standard is specifically designed for testing air content in freshly mixed concrete using the pressure method. This standard is essential for ensuring the quality and durability of concrete, as the air content affects both the concrete's resistance to freeze-thaw cycles and its workability. ASTM, the American Society for Testing and Materials, sets guidelines for various materials testing procedures.
ASTM standards like ASTM C231 are critical in the field of construction and civil engineering, providing guidelines that assure materials meet specific requirements for their intended use. ASTM D143 pertains to tests for small clear specimens of timber, ASTM E329 deals with standards for agencies engaged in construction inspection, testing, or Special Inspection, and ASTM A36 is a specification for carbon structural steel. Thus, ASTM C231 is the specific standard relevant for air content testing in concrete.