Which ASTM standard covers carbon-steel reinforcing bars commonly used in structural concrete?

• A. ASTM A500
• B. ASTM C150
• C. ASTM A615
• D. ASTM A1035

Answer: (C)

ASTM A615 is the standard that defines carbon-steel reinforcing bars used in structural concrete. It covers both plain and deformed bars, which are the typical forms you’ll see in reinforced concrete, and it specifies the mechanical properties, sizes, tolerances, and grades (like 40 and 60) that determine how much strength and how easily the bars will bond with concrete. This standard ensures that the rebar provides the intended tensile strength and anchorage in concrete members, with ribbed or deformed surfaces that improve grip within the concrete matrix. The other options pertain to different materials or applications (for example, sections for hollow structural shapes or cement specifications) and do not define the common carbon-steel reinforcing bars used in structural concrete. So, the reinforcement standard used for this purpose is ASTM A615.