250+ TOP MCQs on Cement Concrete Construction – Proportioning Concrete and Answers

Construction and Building Materials Multiple Choice Questions & Answers (MCQs) on “Cement Concrete Construction – Proportioning Concrete”.

1. The process of selection of relative proportions of cement, sand, course aggregate and water, so as to obtain a concrete of desired quantity is known as the ________
a) Proportioning of reinforcement
b) Proportioning of concrete
c) Proportioning of cement
d) Proportioning of water
Answer: b
Clarification: Proportioning of concrete result is independent of the size of stones. It is interesting to note that if sand is taken in place of stones, the same result will be obtained. The result can be verified by pouring water in the vessel, it is just full.

2. The theory of formation of __________ is based on the phenomenon of the formation of voids.
a) Concrete
b) Cement
c) Water-cement
d) Slurry
Answer: a
Clarification: In this theory, when coarse aggregate is placed, voids are formed. When fine aggregates i.e. sand is added, it occupies these voids. Further, when finely powdered cement is added, it occupies the voids of sand particles.

3. In _______ method of volumetric proportions, the proportions of cement, sand and coarse aggregate are fixed or beta really such as 1:2:4 or 1:3:6 etc.
a) Minimum void method
b) Maximum void method
c) Water-cement ratio method
d) Arbitrary method
Answer: d
Clarification: In Arbitrary method, there is no rigid control over the strength of the concrete mix. However, this method is widely used for all works of small magnitude because of its simplicity in the design.

4. 1:2:4, 1:3:6, etc. Are used in which method of volumetric proposition.
a) Minimum void method
b) Water-cement ratio method
c) Arbitrary method
d) Finesse modulus method
Answer: c
Clarification: In Arbitrary method of volumetric proportions, the proportions of cement are depending on the nature of work for which concrete is required. Thus the general expression for proportions of cement, sand and coarse aggregate is 1:n:2n by volume.

5. For lean concrete bases and simple foundation for masonry walls ________ grades of concrete may be used.
a) M40 and M35
b) M5 and M7.5
c) M10 and M20
d) M1.5 and M2.5
Answer: b
Clarification: The letter M refers to the mix and the number indicates the specified concrete compressive strength of that makes at 28 days expressed in Newton per mm square. The grades of concrete lower than M15 are not to be used in RCC work.

6. In ________ method, the fineness modulus of sand and aggregate is determined by the standard tests.
a) Fineness modulus method
b) Minimum void method
c) Arbitrary method
d) Maximum void method
Answer: a
Clarification: The Tom fineness modulus is used to indicate an index number which is roughly proportional to the average size of the particle in the enter quantity of aggregates. The number of the BIS sieves used are from 80 mm to number 15, which are used to determine the fineness modulus.

7. In ________ Method, the voids of coarse aggregate and fine aggregate are determined separately.
a) Arbitrary method
b) Minimum void method
c) Maximum void method
d) Optimum void method
Answer: b
Clarification: In Minimum void method, the quantity of fine aggregate used in the mix is about 10% more than the voids in the coarse aggregate and the quantity of cement is kept at about 15% more than the voids in the fine aggregate.

8. ________ method is based on the principle that the densest concrete is achieved by proportioning its aggregate in such a manner that the heaviest weight of concrete for same volume is obtained.
a) Minimum void method
b) Arbitrary method
c) Water-cement ratio method
d) Maximum void method
Answer: d
Clarification: In Maximum void method, a box is filled with varying proportions of fine and coarse aggregate. The proportion which give the heaviest weight is then adopted. The method of maximum density is not very popular because the grades cannot be accurately achieved.

9. The strength of well compacted concrete with good workability is depended only on the _________
a) Water content
b) Cement content
c) Water-cement ratio
d) Water-soaked ratio
Answer: c
Clarification: Similarly the higher water content increases the workability. But it is not useful for chemical action. The excess water evaporates living pores in the concrete. Thus the increase water cement ratio lowers the strength of concrete.

10. According to the __________ law given by Abram as a result of many experiments, the strength of well compacted concrete with good workability is dependent only on the water cement ratio.
a) Water content law
b) Water-cement ratio law
c) Water-sand ratio law
d) Cement content law
Answer: b
Clarification: It is noted that to apply Water-cement ratio law, the concrete is assumed to be fully compacted. The lower water content produces stiff paste having greater binding property and hence the lowering of water cement ratio within certain elements results in the increase strength.