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WorksheetsDay 36-worksheet-Btech-Concrete technology part 2
Total questions: 15
Worksheet time: 15mins
Name
Class
Date
1.
The characteristic compressive strength of concrete is the value below which not more than ____% of test results are expected to fall.
a)
2%
b)
5%
c)
10%
d)
15%
2.
As per IS 456, the modulus of elasticity of concrete Ec is taken as:
a)
5300 √fck
b)
5000 fck
c)
5000 √fck
d)
4400 √fck
3.
Flexural strength of concrete is conventionally expressed as:
a)
Modulus of toughness
b)
Modulus of resilience
c)
Modulus of rupture
d)
Modulus of elasticity
4.
Superplasticizer is MOST suitable when:
a)
Low slump concrete is required
b)
Pumpable concrete over long distance is required
c)
Curing is difficult
d)
Concrete is air-entrained
5.
Minimum grade of concrete for RCC in EXTREME exposure as per IS 456 is:
a)
M20
b)
M25
c)
M30
d)
M40
6.
In mix proportioning, water content is increased by approximately ___% for every additional 25 mm slump (beyond 50 mm).
a)
1%
b)
2%
c)
3%
d)
5%
7.
Shrinkage of concrete is a volumetric change due to loss of moisture and it is time dependent.
a)
True
b)
False
8.
Admixtures improve properties of concrete but they cannot reduce the required water content.
a)
True
b)
False
9.
Assertion (A): Air-entraining admixtures improve workability. Reason (R): They introduce microscopic stable air bubbles that act as ball bearings.
a)
A True, R True, R is correct explanation
b)
A True, R True, but R not the explanation
c)
A True, R False
d)
A False, R True
10.
The…………….is defined as the ratio of ultimate creep strain to elastic strain.
(a)
11.
For RCC under severe exposure, the maximum free water–cement ratio permitted is …….
(a)
12.
A high-range water-reducing admixture is called:
a)
Retarder
b)
Air entrainer
c)
Superplasticizer
d)
none
13.
Choose the correct increasing order of water reduction capacity:
a)
Retarder → Plasticizer → Superplasticizer
b)
Plasticizer → Retarder → Superplasticizer
c)
Superplasticizer → Plasticizer → Retarder
d)
Retarder → Superplasticizer → Plasticizer
14.
Choose the ONLY correct pair:
a)
Shrinkage – sustained loading
b)
Creep – moisture loss
c)
Durability – unrelated to permeability
d)
none
15.
Pick the TRUE statement:
a)
Air entrainment always reduces strength drastically
b)
Flexural strength is tested using cylinders
c)
Creep is independent of duration
d)
Characteristic strength is based on 28‑day cube test
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