ASCE Structural Engineering and Materials 4 — Questions and Answers
Question 1: Which expression gives the Euler critical buckling load of a column?
- π²EI/(KL)² (Correct answer)
- πEI/(KL)
- EI/(KL)²
- π²EA/(KL)
Correct answer: π²EI/(KL)²
The Euler load is Pcr = π²EI/(KL)².
Question 2: What is the specified minimum yield strength of ASTM A992 steel, the standard for W-shapes?
- 36 ksi
- 50 ksi (Correct answer)
- 65 ksi
- 100 ksi
Correct answer: 50 ksi
A992 has Fy = 50 ksi and Fu = 65 ksi.
Question 3: Lateral-torsional buckling capacity of a steel W-beam depends most directly on which parameter?
- Web thickness only
- Unbraced length of the compression flange (Lb) (Correct answer)
- Bolt diameter
- Concrete cover
Correct answer: Unbraced length of the compression flange (Lb)
AISC F2 lowers flexural strength as Lb grows past Lp and again past Lr.
Question 4: What is the fixed-end moment at each support of a fixed-fixed beam under uniform load w over span L?
- wL²/8
- wL²/24
- wL²/12 (Correct answer)
- wL²/16
Correct answer: wL²/12
Each fixed-end moment is wL²/12, and the midspan moment is wL²/24.
Question 5: In the moment distribution method, what is the carry-over factor to a far end that is fixed (prismatic member)?
- 0
- 0.5 (Correct answer)
- 0.75
- 1.0
Correct answer: 0.5
For a prismatic member, half of the moment applied at the near end carries over to a fixed far end.
Question 6: Which prestress loss is instantaneous rather than time-dependent?
- Creep of concrete
- Shrinkage of concrete
- Relaxation of tendons
- Elastic shortening of concrete (Correct answer)
Correct answer: Elastic shortening of concrete
Elastic shortening happens the moment prestress is transferred; creep, shrinkage, and relaxation build up over time.
Question 7: Class F fly ash, used as a supplementary cementitious material, is best described as:
- High-calcium and self-cementing
- Low-calcium pozzolan (Correct answer)
- An air-entraining admixture
- A set accelerator
Correct answer: Low-calcium pozzolan
Class F fly ash is a low-calcium pozzolan that reacts with calcium hydroxide and has little self-cementing ability.
ASCE Structural Engineering and Materials 4
Which expression gives the Euler critical buckling load of a column?