What is the primary purpose of grouting the cores around vertical reinforcement in CMU walls?

• A. It secures reinforcement and ensures load transfer.
• B. It increases wall color uniformity.
• C. It reduces reinforcement corrosion without affecting load.
• D. It eliminates the need for reinforcing bars.

Answer: (A)

Grouting the cores around vertical reinforcement creates composite action between the masonry and the steel, locking the bars in place and forming a continuous structural element. When the grout fills the cores, it bonds with both the masonry units and the steel, so loads carried by the wall—compression, shear, and bending—are shared between the grout, brick or block, and rebar. This transfer of load improves the wall’s stiffness and strength and helps prevent movement of the reinforcement, which could weaken the wall if the bars could slip or buckle.

Cosmetic color variation is not the goal of grouting, and while grout can offer some protection to the bars, the primary purpose is to secure the reinforcement and ensure proper load transfer. Grouting does not eliminate the need for reinforcing bars; in fact, it relies on them to develop the wall’s strength.