Q.1) A structural member is generally designed so that the material is stressed up to :
A) Breaking stress
B) Yield stress
C) Ultimate stress
D) Working stress
Breaking stress : Breaking stress is the maximum stress that a material can withstand before breaking or fracturing. It is also known as the tensile strength or ultimate tensile strength.
Yield stress : Yield stress is the maximum stress at which a material undergoes plastic deformation i.e. it will deform permanently without returning to its original shape when the stress is removed. It is the point at which a material no longer behaves elastically and will continue to deform under a constant load.
Ultimate stress : The highest stress that a material can withstand before failing, usually by fracture or extreme deformation, is known as ultimate stress. It is also known as the ultimate strength or the ultimate load. A material can typically withstand this amount of tension before breaking.
Working stress : Working stress, sometimes referred to as allowable stress or design stress, is the highest amount of stress that a material can withstand without permanent deformation or failure while operating normally. When safety considerations and other aspects for the particular application are taken into account, working stress is often a small portion of the material’s yield stress or ultimate stress.
Q.2) As per IS : 456 – 2000, when HYSD bars are used, the minimum reinforcement in either direction of slabs is :
A) 0.12% of total c/s area
B) 0.35% of total c/s area
C) 0.80% of total c/s area
D) 0.25% of total c/s area
Minimum reinforcement for slab –
- Ast(min) = 0.15% * Gross sectional area [Fe 250 bar]
- Ast(min) = 0.12% * Gross sectional area [HYSD bar]
Q.3) A concrete mix of grade M40 is to be used for pavements using paver machine. The recommended slump range as per IS:456-2000 is :
A) 25 – 75 mm
B) 75 – 100 mm
C) 100 – 150 mm
D) 50 – 100 mm
Slump values for different types of structures as per IS:456-2000 :
- Road pavement = 25 – 75 mm
- Under water concrete work = 100 -150 mm
- Column and foundation = 25 – 75 mm
- Mass concrete work = 25 – 50 mm
- Dense concrete work = 50 – 100 mm
Q.4) As per IS:456-2000, normally structures are designed with one or more expansion joints exceeding :
A) 60 m in length
B) 80 m in length
C) 45 m in length
D) 75 m in length
Q.5) In R.C.C., steel is used because it can provide good :
A) Bond strength
B) Tensile strength
C) Compressive strength
D) Shear strength
Concrete is good in compression whereas Steel is good in tension. Thus, combination of both makes strong and reliable structure.
Q.6) The permissible stress to which a structural member can be subjected is known as :
A) Tensile stress
B) Working stress
C) Bearing stress
D) Compressive stress
Working stress is the stress lower than the maximum or ultimate stress at which failure of the material takes place .
Q.7) The short term static modulus of elasticity for concrete of grade M25 is –
A) 250 MPa
B) 25 MPa
C) 25 GPa
D) 2500 MPa
Short term static modulus of elasticity,
Ec = 5000√fck = 5000 √25 = 25000 N/mm2 = 25 GPa
Q.8) Lap length of reinforcement in compression shall not be less than :
Lap length for different conditions :
- In compression : ≤ 24 Φ.
- In flexible tension : Ld or 35 Φ (greater of both).
- In direct tension : 2Ld or 35Φ (greater of both).
where, Ld is development length.
Q.9) The maximum spacing of shear reinforcement should not exceed 0.75d subjected to a minimum of :
A) 450 mm
B) 300 mm
C) 400 mm
D) 350 mm
Q.10) The maximum area of tension steel in a beam shall not exceed –
A) 0.12 bD
B) 1.15 bD
C) 0.15 bD
D) 0.04 bD
Maximum tension steel that can be provided in a beam is 4% of gross cross sectional area i.e. (4/100)*bD = 0.04 bD.
Q.11) The shear reinforcement in a RCC beam is provided to resist :
A) Punching shear
B) Diagonal tension
C) Shear in concrete
D) Flexural shear
Q.12) The load-carrying capacity of a helically reinforced column as compared to that of a tied column is about –
A) 10% less
B) 10% more
C) 5% less
D) 5% more
Q.13) The maximum permissible final deflection of a beam should not exceed :
Q.14) Maximum spacing of vertical stirrups permitted in RC beam having depth D is _____.
A) 0.5 D
B) 0.75 D
C) 0.25 D
D) 2.5 D
Maximum of shear reinforcement shall be minimum of :
- 0.75 d (vertical stirrups)
- d (inclined stirrups)
- 300 mm
Q.15) Doubly reinforced beam is recommended when :
A) both depth and width are restricted
B) the shear is high
C) the width of the beam is restricted
D) the depth of the beam is restricted
If load condition is such that depth of singly reinforced beam becomes very large, instead of designing singly reinforced beam we go for doubly reinforced beam.
Q.16) The minimum HYSD reinforcement in a slab :
Q.17) Which of the following properties is not required for concrete mix design, as per the guidelines given by the Indian Standard?
A) Density of aggregate
B) Specific gravity of cement
C) Characteristic strength of concrete
D) Maximum size of aggregate
Mix design involves choosing the ideal blend of raw materials in precise ratios to create concrete that possesses the necessary characteristics for specific purposes in both its fresh and solidified states.
Q.18) As per IS – 456:2000, the total thickness of flat slab should not be less than :
A) 1.5 m
B) 2 m
C) 1 m
D) 2.5 m
Q.19) The effective depth of a T-beam for heavy loads is taken as –
A) 1/15th of the span
B) 1/12th of the span
C) 1/18th of the span
D) 1/10th of the span
Q.20) In reinforced concrete footing on soils, the minimum thickness at the edge should not be less than –
A) 200 mm
B) 100 mm
C) 150 mm
D) 250 mm