Civil Engineering Drawing Multiple Choice Questions on “Structural Designing and Thumb Rules”.
1. The maximum area of tension reinforcement in beams shall not exceed?
a) 1.5%
b) 4%
c) 7%
d) 0.5%
Answer: b
Clarification: If tensile reinforcement of beam should exceed 4% of total gross area then some crack will be developed in concrete.
2. The diameter of longitudinal bars of a column should never be less than?
a) 12 mm
b) 6 mm
c) 10 mm
d) 8 mm
Answer: a
Clarification: Minimum diameter of longitudinal bar in RCC column shall not be less than 12mm (IS456:2000, cl 26.5.3.1 d). Indian standards specify 12mm as the least diameter of a vertical bar and 5mm as the least diameter of lateral bar or stirrup.
3. The number of treads in a flight is equal to _________
a) risers in the flight
b) risers plus one
c) risers minus one
d) risers plus three
Answer: c
Clarification: It is often not simply the sum of the individual tread lengths due to the nosing overlapping between treads. If there are N steps, the total run equals N-1 times the going: the tread of the last step is part of a landing and is not counted.
4. A foundation rests on __________
a) base of the foundation
b) foundation soil
c) subgrade
d) foundation soil and subgrade
Answer: d
Clarification: A foundation (or, more commonly, base) is the element of an architectural structure which connects it to the ground, and transfers loads from the structure to the ground. Foundations are generally considered either shallow or deep. Foundation engineering is the application of soil mechanics and rock mechanics (Geotechnical engineering) in the design of foundation elements of structures.
5. For initial estimate for a beam design, the width is assumed?
a) 1/10th of span
b) 1/30th of span
c) 1/15th of span
d) 1/5th of span
Answer: b
Clarification: Design codes prescribe beam width limitations to minimise the shear lag effect on the formation of full-width plastic hinges and achieving the expected capacity. However, owing to insufficient experimental and analytical studies, empirical design formulas for the beam width limitation, with remarkably different results, have been implemented in different design codes. In this paper, parametric studies of the influence of key parameters on the behaviour of wide beam–column connections are conducted based on available test results. An effective beam-width model is analytically developed using the equivalent-frame representation, where the effects of torsion of transverse beams and flexure around the joint core are considered. The validity of the model is verified using flexural strengths of test specimens, covering a wide range of design parameters.
6. Design of R.C.C. simply supported beams carrying U.D.L. is based on the resultant B.M. at ____________
a) mid span
b) supports
c) every section
d) quarter span
Answer: a
Clarification: Since BM is maximum at midspan, design should be done for maximum bending moment so that it will take care for other section. Moment formula we are using is (wl2/8) which mid span moment.
7. High strength concrete is used in prestressed member?
a) To ovecome bursting stresses at the ends
b) To provide high bond stresses
c) To overcome cracks due to shrinkage
d) To overcome bursting stresses, provide high bond stresses and overcome cracks
Answer: d
Clarification: The primary difference between high-strength concrete and normal-strength concrete relates to the compressive strength that refers to the maximum resistance of a concrete sample to applied pressure. Although there is no precise point of separation between high-strength concrete and normal-strength concrete, the American Concrete Institute defines high-strength concrete as concrete with a compressive strength greater than 6,000 psi.
8. The advantage of reinforced concrete is due to ___________
a) monolithic character
b) moulding in any desired shape
c) fire-resisting and durability
d) monolithic character, moulding any shape and fire-resisting
Answer: d
Clarification: Reinforced concrete (RC) is a composite material in which concrete’s relatively low tensile strength and ductility are counteracted by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (rebar) and is usually embedded passively in the concrete before the concrete sets. Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with rebar or not. Reinforced concrete may also be permanently stressed (in tension), so as to improve the behaviour of the final structure under working loads.
9. Cracking of the concrete section is nearly impossible to prevent.
a) True
b) False
Answer: a
Clarification: However, the size and location of cracks can be limited and controlled by appropriate reinforcement, control joints, curing methodology and concrete mix design. Cracking can allow moisture to penetrate and corrode the reinforcement. This is a serviceability failure in limit state design. Cracking is normally the result of an inadequate quantity of rebar, or rebar spaced at too great a distance. The concrete then cracks either under excess loading, or due to internal effects such as early thermal shrinkage while it cures.
Ultimate failure leading to collapse can be caused by crushing the concrete, which occurs when compressive stresses exceed its strength, by yielding or failure of the rebar when bending or shear stresses exceed the strength of the reinforcement, or by bond failure between the concrete and the rebar.
10. The architect is usually the lead designer on buildings, with a structural engineer employed as a sub-consultant.
a) False
b) True
Answer: b
Clarification: The degree to which each discipline actually leads the design depends heavily on the type of structure. Many structures are structurally simple and led by architecture, such as multi-storey office buildings and housing, while other structures, such as tensile structures, shells and gridshells are heavily dependent on their form for their strength, and the engineer may have a more significant influence on the form, and hence much of the aesthetic, than the architect.