Building Engineering Building Civil Engineering 3 — Questions and Answers
Question 1: What does the 'slump test' measure for freshly mixed concrete?
- Compressive strength
- Workability (consistency) (Correct answer)
- Air content
- Setting time
Correct answer: Workability (consistency)
The slump test measures the consistency and workability of fresh concrete by recording how much a cone of concrete settles.
Question 2: Which load combination typically governs the design of a building foundation according to ASCE 7?
- D only
- D + L
- 1.2D + 1.6L (Correct answer)
- 0.9D + 1.0W
Correct answer: 1.2D + 1.6L
The combination 1.2D + 1.6L (dead load + live load) is typically the controlling factored load for foundation design under gravity conditions.
Question 3: What is the function of a moment frame in a structural building system?
- Resist axial column loads only
- Resist lateral loads through rigid beam-column connections (Correct answer)
- Transfer shear along diaphragms
- Distribute wind pressure to cladding
Correct answer: Resist lateral loads through rigid beam-column connections
A moment frame resists lateral loads through the rigidity of beam-to-column connections, allowing the frame to develop bending moments.
Question 4: In soil mechanics, what is the 'angle of internal friction' (φ) a measure of?
- Soil cohesion under saturated conditions
- Shear strength from particle interlocking (Correct answer)
- Permeability of granular soils
- Soil compressibility under load
Correct answer: Shear strength from particle interlocking
The angle of internal friction represents the shear strength contribution from inter-particle friction and interlocking in granular soils.
Question 5: Which type of pile transfers load primarily through friction along its shaft rather than end bearing?
- End-bearing pile
- Friction (floating) pile (Correct answer)
- Belled pier
- Caisson pile
Correct answer: Friction (floating) pile
Friction piles transfer structural loads to the soil through skin friction along the pile shaft when competent bearing strata are too deep.
Question 6: What is 'elastic shortening' in prestressed concrete construction?
- Concrete shrinkage over time due to drying
- Immediate shortening of concrete when prestress force is applied (Correct answer)
- Creep deformation under sustained load
- Thermal expansion under temperature change
Correct answer: Immediate shortening of concrete when prestress force is applied
Elastic shortening occurs immediately when the prestressing force is transferred to the concrete, causing an instantaneous compressive strain.
Question 7: According to IBC, what minimum live load is typically required for office floors?
- 25 psf
- 40 psf
- 50 psf (Correct answer)
- 100 psf
Correct answer: 50 psf
The IBC requires a minimum uniform live load of 50 psf for office occupancies.
Building Engineering Building Civil Engineering 3
What does the 'slump test' measure for freshly mixed concrete?