What is the required concrete strength for foundation walls in seismic design category D according to CBC?
Correct Answer
B) 3,000 psi
CBC requires minimum 3,000 psi concrete strength for foundation walls in high seismic zones (SDC D) to ensure adequate structural performance during seismic events.
Why This Is the Correct Answer
CBC and ACI 318 require a minimum compressive strength of 3,000 psi (f'c = 3,000 psi) for concrete in foundation walls located in Seismic Design Category D. This minimum ensures the concrete can withstand the cyclic loading, shear forces, and ductility demands imposed during a significant seismic event.
Why the Other Options Are Wrong
Option A: 4,000 psi
4,000 psi exceeds the CBC minimum requirement and is often used in higher-performance or commercial applications, but it is not the required minimum for residential foundation walls in SDC D. Specifying 4,000 psi is not wrong from a quality standpoint, but it does not answer the question of what the code requires.
Option C: 2,500 psi
2,500 psi was a common historical minimum but is no longer sufficient for seismic design categories. Modern CBC requirements in high-seismic zones (SDC D and above) mandate at least 3,000 psi to provide adequate structural performance.
Option D: 3,500 psi
3,500 psi is above the minimum requirement and would satisfy the code, but it is not the specified minimum. The question asks for the required (minimum) strength, not an acceptable strength — an important distinction on licensing exams.
Memory Technique
SDC D = 3,000 psi minimum. Think 'D for Demanding — demands 3,000.' The step up from 2,500 to 3,000 happens when you enter seismic design categories that require special structural performance.
More California Questions
A contractor is installing shear walls in a residence located in Seismic Design Category D. The engineer's plans call for 15/32-inch structural sheathing with 8d nails at 6 inches on center at panel edges. The contractor wants to substitute 7/16-inch OSB with the same nailing. Is this substitution acceptable?
You are reviewing plans for a mixed-use building where the ground floor will house a restaurant with commercial kitchen equipment. The architect has specified standard residential electrical requirements throughout. What Title 24 compliance issue should you identify?
According to CBC seismic provisions, what is the concept behind the 'strong column, weak beam' design philosophy?
A residence in California has 2,800 sq ft of conditioned space. The HVAC system efficiency is 16 SEER. What is the approximate Title 24 compliance margin compared to the minimum 14 SEER requirement?
You're constructing a foundation on liquefiable soils identified in a California coastal area. The geotechnical report recommends deep foundations. Which option is most commonly specified?
A contractor is installing a heat recovery ventilation (HRV) system to comply with Title 24. The system serves a 2,000 sq ft house with 3 bedrooms. What is the minimum required ventilation rate?
During construction of a basement in sandy soil conditions, you encounter groundwater at 4 feet below grade. The basement extends 8 feet below grade. What is the critical design consideration per CBC?
During a seismic retrofit project, you discover that existing concrete has a compressive strength of 2,200 psi. The engineer specifies new anchor bolts that require 2,500 psi minimum concrete strength. What is the most appropriate action?
What is the maximum allowable notch depth in a 2x10 floor joist per CBC requirements?
You're reviewing plans for a wood-framed structure in seismic design category D. The project calls for a shear wall with 15/32-inch structural sheathing and 8d nails spaced 6 inches on center at panel edges. What is the allowable shear value per the CBC?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass
Related Study Resources
Previous Question
Title 24 requires fenestration products to meet specific performance criteria. What does the Solar Heat Gain Coefficient (SHGC) measure?
Next Question
Under Title 24, a new home's HVAC system must meet specific duct sealing requirements. What is the maximum allowable duct leakage rate for new construction?