What is the minimum concrete cover required for #6 rebar in a concrete footing that will be in direct contact with soil?
Correct Answer
C) 3 inches
According to ACI 318, reinforcement in concrete cast against and permanently exposed to earth requires a minimum cover of 3 inches. This protects the rebar from corrosion and ensures proper concrete protection.
Why This Is the Correct Answer
According to ACI 318 building code, reinforcement in concrete that is cast against and permanently exposed to earth requires a minimum cover of 3 inches. This requirement applies to footings in direct contact with soil, regardless of the rebar size. The 3-inch cover provides adequate protection against corrosion from moisture and chemicals in the soil, while ensuring proper bond between the concrete and reinforcement.
Why the Other Options Are Wrong
Option A: 1.5 inches
1.5 inches is insufficient cover for concrete in contact with earth. This cover requirement might apply to interior concrete elements not exposed to weather or soil, but does not provide adequate protection against soil moisture and corrosive elements.
Option B: 2 inches
2 inches is the minimum cover requirement for concrete exposed to weather or earth for bars #5 and smaller, or for concrete not exposed to weather when bar diameter is #6 through #18. Since this footing is in direct contact with soil, the 3-inch requirement applies.
Option D: 4 inches
4 inches exceeds the minimum requirement and would be unnecessarily conservative for this application. While not technically wrong from a protection standpoint, it's not the minimum required by code and would be wasteful of materials.
Memory Technique
Think 'Dirty Concrete = 3' - when concrete touches dirt (soil), you need 3 inches of cover to keep the rebar clean and protected.
Reference Hint
ACI 318 Building Code Requirements for Structural Concrete, Chapter 20 - Reinforcement Details, Table 20.6.1.3.1 for minimum concrete cover requirements
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
An accessible parking space detail shows dimensions of 8 feet wide with a 5-foot access aisle. A van-accessible space is also required. What should be the width of the van-accessible space?
Next Question
You're installing a built-up roof system on a commercial building in Miami. The roof deck is slightly damp from morning dew. What should you do?