What is the purpose of anchor bolts and their relation to reinforcement?

• A. They connect to anchor plates only
• B. They tie into concrete and allow attachment of structural members; embedment and spacing must be coordinated with rebar needs
• C. They replace the need for rebar in foundations
• D. They only hold formwork in place

Answer: (B)

Anchor bolts are used to secure structural members to a concrete foundation and to transfer loads from the steel into the concrete. They are embedded in the concrete so base plates, columns, or equipment can be bolted to the foundation and resist tension and shear forces. The embedment depth and bolt spacing must be coordinated with the reinforcing bars to avoid interfering with rebar, maintain adequate concrete cover, and ensure the bolts can develop their designed strength without compromising the reinforcement. In other words, anchor bolts work together with rebar: rebar provides the main tensile reinforcement in the concrete, while the bolts provide the connection points and anchorage for structural members. They do not replace rebar, nor are they only for holding formwork or connecting to anchor plates alone.