What is the maximum spacing for rebar placement in reinforced concrete walls thicker than 8 inches?

The maximum spacing for rebar placement in reinforced concrete walls thicker than 8 inches is set at 12 inches on center because this distance helps ensure adequate support and structural integrity. Reinforced concrete relies on the tensile strength of the rebar to resist bending and shear forces, especially in thicker walls where the stresses can be more significant.

By maintaining a maximum spacing of 12 inches, the design ensures that the rebar effectively distributes the loads throughout the wall. This spacing also helps mitigate issues such as cracking or unexpected failure that could arise from excessive spacing. If rebar were spaced further apart, there would be an increased risk of structural weakness, which could compromise the wall's performance under load or during seismic events.

The other options for maximum spacing—16, 24, or 30 inches—would exceed the recommended parameters, especially for concrete walls thicker than 8 inches, potentially leading to inadequate reinforcement and increased vulnerability to structural failure. Keeping the spacing at a maximum of 12 inches on center is a standard practice rooted in engineering principles and codes that ensure safe and effective design in construction.