This set of Building Construction Multiple Choice Questions & Answers (MCQs) focuses on “Types of Upper Floors – 1”.
1. R.S.J. stands for _________
a) Reinforced steel joists
b) Reinforced stone joists
c) Rolled steel joists
d) Rolled stone joists
Explanation: The full form of R.S.J is rolled steel joists. The cross-section of an R.S.J. beam is usually I or H shaped. It is generally made of mild steel but aluminium and some other materials can also be used.
2. The bearing of joists on the wall should not be less than half of the width of the wall.
Explanation: The bearing of joists on the wall should not be less than half of the width of the wall. It is generally kept equal to the width of the wall in order to eliminate the eccentric load of the wall. The bearing of joists should also be at least equal to the depth of the joist.
3. In steel joist and stone floors, the clear span of the joists is equal to the ___________ of the room.
Explanation: In steel joist and stone floors, the clear span of the joists is equal to the width of the room. Length of available stone slabs is a factor on which the spacing of the rolled steel joists depends.
4. In jack arch floors, the rise of the arch is equal to ________ of the span.
Explanation: In jack arch floors, the rise of the arch is equal to 1/12 of the span. Jack arch is an arch made of either concrete or brick. In this, the spacing between the joists is 1-1.5 m placed center to center.
5. The minimum depth of concrete at the crown in jack arch floors is _________
a) 5 cm
b) 10 cm
c) 15 cm
d) 20 cm
Explanation: The minimum depth of concrete at the crown in jack arch floors is 15 cm. In this type of floors, steel ties rods are also provided at the end span generally spaced at 1.8-2.4 m c/c. These are provided because of the tension developed at the end span.
6. Which of the following precautions is not correct while constructing brick jack arch floors?
a) Key brick should be properly secured in mortar
b) R.S.J should be properly secured in position
c) Only first class bricks are used
d) Any class of bricks can be used
Explanation: Proper precautions must be taken while constructing brick jack arch floors. These are – key brick should be properly secured in the mortar, R.S.J should be properly secured in position and only first class bricks should be used.
7. ___________ is a curved-triangular space formed between the outer curve of an arch and a horizontal line through the crown.
Explanation: The curved-triangular space formed between the outer curve of an arch and a horizontal line through the crown is known as spandrel. The outer curve of the arch is known as extrados.
8. In brick jack arch flooring, joists are encased in ___________ mortar, for preventing their rusting from _________ mortar.
a) Lime, cement
b) Cement, lime
c) Mud, cement
d) Mud, lime
Explanation: In brick jack arch flooring, joists are encased in cement mortar, for preventing their rusting from the lime mortar. In this type of flooring, only well-burnt bricks should be used for construction and they are saturated with water before using them.
9. Arch in cement concrete jack flooring is made of __________ cement concrete.
Explanation: Arch in cement concrete jack flooring is made of 1:2:4 cement concrete. The arches are supported on the lower flanges of mild steel joists. The method of construction of cement concrete jack floors is comparatively easy.
10. The thickness of the mild steel plates provided in the centring of cement concrete jack floors is ________
a) 1 mm
b) 3 mm
c) 5 mm
d) 7 mm
Explanation: The thickness of the mild steel plates provided in the centring of cement concrete jack floors is 3 mm. The centring has a pair of holes at the ends which are spaced at 75 cm c/c. The steel plate is bent in the shape of the arch soffit.
11. Which of the following is not a type of R.C.C. floor?
a) Simple slab flooring
b) Reinforced slab flooring
c) Curved slab flooring
d) Flat slab flooring
Explanation: There are various types of R.C.C. floors. These are simple slab flooring, reinforced slab flooring, flat slab flooring, beam slab flooring and ribbed flooring.
12. R.C.C stands for ___________
a) Rolled cement concrete
b) Reinforced cement concrete
c) Rolled concrete cement
d) Reinforced concrete cement
Explanation: Reinforced cement concrete is the full form of R.C.C. It is extensively used for the construction of floors of modern buildings. R.C.C. floors are relatively fireproof and damp proof and have many other advantages over other types of floors.
13. R.C.C is strong in tension and weak in compression.
Explanation: Reinforced cement concrete is strong in compression and weak in tension. Due to this property, it is usually reinforced with the help of steel bars. The entire bending tension is taken by these steel bars. It also results in R.C.C. floors having a comparatively smaller thickness.
14. ____________ reinforcement is known as temperature reinforcement.
Explanation: Nominal reinforcement is known as temperature reinforcement. It is also known as distribution reinforcement. In simple reinforced cement concrete flooring, nominal reinforcement is provided in a perpendicular direction.
Explanation: The above figure shows a filler joist floor. In this figure, A represents flooring, B represents filler joist and C represents concrete fill. In this type of flooring, the filler joists either rest on walls or on longitudinal steel beams.
Sanfoundry Global Education & Learning Series – Building Construction.
To practice all areas of Building Construction, here is complete set of 1000+ Multiple Choice Questions and Answers.