What devices are used to maintain concrete cover and spacing from forms and other bars?

• A. Welding rods
• B. Cover blocks or spacers
• C. Tape measures
• D. Tie wires

Answer: (B)

Maintaining proper concrete cover and spacing from forms and other bars is achieved with cover blocks and spacers. These devices sit around the reinforcing bars to hold them at the correct distance from the form face and from nearby bars, ensuring there is enough concrete around the steel for protection, bonding, and fire resistance. They keep everything in the right position during placement so the concrete pours evenly and the reinforcement remains properly positioned. Welding rods are for welding, not for positioning; tape measures are tools for measuring, not for actual placement; and tie wires are used to bundle and hold bars together, not to maintain the required cover and spacing.