A structural drawing shows a beam with the notation '#4 @ 12" O.C.' What does this specify?
Correct Answer
A) Number 4 rebar spaced 12 inches on center
The notation '#4 @ 12" O.C.' specifies Number 4 reinforcement bars (rebar) placed at 12-inch intervals on center. This is standard reinforcement notation used in structural drawings.
Why This Is the Correct Answer
The notation '#4 @ 12" O.C.' is standard reinforcement notation used throughout the construction industry. The '#4' specifically refers to Number 4 rebar, which has a diameter of 1/2 inch. The '@ 12" O.C.' means the rebar is spaced at 12-inch intervals measured from center to center of each bar. This notation system is universally used in structural drawings to specify reinforcement placement in concrete elements.
Why the Other Options Are Wrong
Option B: 4 beams spaced 12 inches apart
The '#' symbol in construction drawings specifically denotes rebar size, not the number of structural members. If the drawing intended to show 4 beams, it would use different notation such as '(4) BEAMS' or show them individually on the plan view.
Option C: Beam size 4 inches by 12 inches
Beam dimensions are shown differently on structural drawings, typically as depth x width (e.g., '12x4' or 'W12x4' for steel beams). The '#' symbol and 'O.C.' notation are exclusive to reinforcement specifications, not member sizing.
Option D: 4 anchor bolts at 12-inch centers
Anchor bolt specifications use different notation, typically showing bolt diameter, length, and spacing (e.g., '1/2" φ x 8" A.B. @ 12" O.C.'). The '#4' designation is exclusively used for rebar sizing in the reinforcement industry standard.
More Project Mgmt Questions
What is the minimum R-value required for wall insulation in Florida Climate Zone 2?
A subcontractor brings a new chemical product to your jobsite. Under the Globally Harmonized System (GHS), what information must be immediately available to workers?
A construction site has a trench that is 8 feet deep in Type B soil. What is the maximum allowable slope ratio for the trench walls without protective systems?
A detail drawing shows a scale of 3/4" = 1'-0". If a dimension measures 2.25 inches on the drawing, what is the actual dimension?
What is the maximum recommended spacing between drywall screws when attaching to wood studs?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Previous Question
A concrete mix design calls for a water-cement ratio of 0.45. If 600 pounds of cement are used, how many gallons of water are needed?
Next Question
A mechanical plan shows a symbol that looks like a rectangle with diagonal lines and the letters 'VAV'. This represents what type of equipment?