Concrete Technology MCQ Questions and Answers in Civil Engineering

Question. The window usualy provided near the main roof of a room and opens above the adjoining verandah, is called ?
a) dormer window
b) corner window
c) bay window
d) clerestorey window

Answer : D

Question. The degree of grinding of cement is called ?
a) fineness
b) soundness
c) impact value
d) bulking

Answer : A

Question. Initial setting time of ordinary Portland cement is ?
a) 15 min
b) 30 min
c) 60 min
d) 10h

Answer : B

Question. The cement concrete prepared by mixing aluminium in it, is called ?
a) air-entrained concrete
b) cellular concrete
c) aerated concrete
d) any one of these

Question. The cement concrete, from which entrained air and excess water are removed after placing it in position, is called ?
a) vacuum concrete
b) light weight concrete
c) prestressed concrete
d) sawdust concrete

Answer : A

Question. Reinforced cement concrete is equally strong in taking ?
a) tensile and compressive stresses
b) compressive and shear stresses
c) tensile, compressive and shear stresses
d) tensile and shear stresses

Answer : C

Question. Too much fineness of cement ?
a) results cracks in concrete
b) generates greater heat
c) develops early strength
d) both (a) and (b)

Answer : D

Question. The sound absorption coefficient of light weight concrete is nearly ........... than that of ordinary concrete ?
a) twice
b) three times
c) four times
d) six times

Answer : A

Question. More water should not be added in the concrete mix, as to increase ?
a) strength
b) durability
c) water-cement ratio
d) all of these

Answer : C

Question. If 30% excess water is added, the strength of concrete is reduced by ?
a) 30%
b) 40%
c) 50%
d) 60%

Answer : C

Question. In the manufacture of cement, the dry or wet mixture of calcareous and argillaceous materials burnt in a ?
a) country kiln
b) continuous flare kiln
c) rotary kiln
d) all of these

Answer : C

Question. The levelling operation that removes humps and hollows and give a true, uniform concrete surface is called ?
a) screeding
b) floating
c) trowelling
d) compacting

Answer : A

Question. The phenomenon by virtue of which the cement does not undergo large change in volume treated with water, is known as ?
a) fineness
b) soundness
c) setting time
d) none of these

Answer : B

Question. For high degree of workability, the slump value should vary between ?
a) 0 to 25 mm
b) 25 to 50 mm
c) 50 to 80 mm
d) 80 to 100 mm

Answer : D

Question. According to the rule of water cement ratio, the strength of concrete wholly depends upon ?
a) the quality of cement
b) the quality of cement mixed with aggregate
c) the amount of water used in preparation of concrete mix
d) all of the above

Answer : C

Question. If the water cement ratio is more, then the ?
a) strength of concrete will be less
b) durability of concrete will be less
c) capillary voids will be more in the physical structure of hydrated cement
d) all of the above

Answer : D

Question. The standard sand now used in India is obtained from ?
a) Ennore (Chennai)
b) Mumbai
c) Orissa
d) Jaipur

Answer : A

Question. The deleterious materials present in the aggregate ?
a) prevent normal hydration of cement
b) reduce the strength and durability of concrete
c) modify the setting action and cause efflorescence
d) all of the above

Answer : D

Question. Insufficient quantity of water ?
a) makes the concrete mix soft
b) makes the concrete mix unworkable
c) causes segregation in concrete
d) causes bleeding in concrete

Answer : B

Question. The number of bags of cement required per cubic metre of 1:2:4 concrete will be approximately ?
a) 2 to 3
b) 3 to 4
c) 4 to 5
d) 5 to 6

Answer : D

Question. Le-chatelier apparatus is used to perform ?
a) fineness test
b) soundness test
c) consistency test
d) compressive strength test

Answer : B

Question. According to IS: 269-1976, the requirement of an ordinary Portland cement is that ?
a) the residue does not exceed 10% when sieved through IS sieve No. 9
b) its expansion is not more than 10 mm for unrated cement
c) its initial setting time is not less than 30 minutes
d) all of the above

Answer : D

Question. For compacting large sections of mass concrete in structures, the type of vibrator used is ?
a) internal vibrator
b) screed vibrator
c) form vibrator
d) all of these

Answer : A

Question. During field test, the cement is said to be pure and of good quality when ?
a) the colour of cement is uniformly greenish grey
b) a handful of cement, thrown into a bucket of water, floats
c) hand is thrusted into a bag of cement, it feels cool
d) all of the above

Answer : D

Question. The resistance of an aggregate to the effect of hydration of cement and weather is called ?
a) crushing value
b) impact value
c) abrasion value
d) soundness

Answer : D

Question. The proportion of lime, silica, alumina and iron oxide in a good Portland cement should be ?
a) 63:22: 6:3
b) 63:22:3:6
c) 22:63:6:3
d) 22:63:3:6

Answer : A

Question. Rolled steel T-sections are used ?
a) to transmit bracket loads to the columns
b) with flat strips to connect plates in the steel rectangular tanks
c) in both (a) and (b)
d) none of these

Answer : C

Question. The presence of ............. in water has an adverse effect on the setting time of cement ?
a) sodium carbonate and bicarbonate
b) calcium chloride
c) sodium chloride
d) sodium sulphate

Answer : A

Question. In transportation of concrete by pumps ?
a) the slump should not be less than 50 mm and more than 80 mm
b) the water cement ratio should remain between 0.5 to 0.65
c) the number of bends in a pipe line should be as small as possible
d) all of the above

Answer : D

Question. As per IS: 459-1978, the concrete mixes are designated into ?
a) 4 grades
b) 5 grades
c) 6 grades
d) 7 grades

Answer : D

Question. The workability of concrete is defined as the ?
a) ease with which it can be mixed, transported and placed in position in a homogenous state
b) breaking up of cohesion in a mass of concrete
c) separation of water or water-cement mixture from the freshly mixed concrete
d) none of the above

Answer : A

Question. In Vicat's apparatus, the diameter of Vicat plunger is ?
a) 5 mm
b) 10 mm
c) 15 mm
d) 20 mm

Answer : B

Question. The material having particle size varying from 0.002 to 0.06 mm is termed as ?
a) silt
b) clay
c) sand
d) none of these

Answer : A

Question. For the improvement of workability of concrete, the shape of aggregate recommended is ?
a) irregular
b) angular
c) round
d) flaky

Answer : C

Question. The minimum particle size of fine aggregate is ?
a) 0.0075 mm
b) 0.075 mm
c) 0.75 mm
d) 0.95 mm

Answer : B

Question. Blast furnace slag cement ?
a) develops low heat of hydration
b) Don’t have early strength
c) develops high heat of hydration
d) has high early strength

Answer : C

Question. Which of the following statement is wrong ?
a) The coarse sand produces a harsh and unworkable mix
b) An admixture cannot increase the workability of concrete without increasing water content
c) Salts of manganese cause a considerable reduction in the strength of concrete
d) all of the above

Answer : B

Question. The term 'ware-house pack' means ?
a) the total capacity of ware-house
b) packing of ware-house
c) pressure compaction of bags on lower layers
d) pressure exertion of bags on upper layers

Answer : C

Question. The water used for ordinary concrete is equal to 5% by weight of aggregate plus ....... by weight of cement ?
a) 10%
b) 20%
c) 30%
d) 40%

Answer : C

Question. Bulk specific gravity of an aggregate is defined as ?
a) the weight of oven dry aggregate divided by its absolute volume, excluding the natural pores in the aggregate particle
b) the weight of oven dry aggregate divided by its absolute volume, including the natural pores in the aggregate particles
c) the weight of aggregate required to fill a container of unit volume
d) the difference in weight of the aggregate in saturated surface dry condition and in moist condition

Answer : B

Question. If 50 kg of fine aggregates and 100 kg of coarse aggregates are mixed in a concrete whose water-cement ratio is 0.6, the weight of water required for harsh mix is ?
a) 8 kg
b) 10 kg
c) 12 kg
d) 14 kg

Answer : C

Question. For batching 1: 2: 4 concrete mix by volume, the ingredients required per bag of cement are ?
a) 50 kg of cement: 70 kg of fine aggregate: 140 kg of coarse aggregate
b) 50 kg of cement : 70 litres of fine aggregate: 140 litres of coarse aggregate
c) 50 kg of cement: 100 kg of fine aggregate: 200 kg of coarse aggregate
d) 50 kg of cement: 100 litres of fine aggregate: 140 litres of coarse aggregate

Answer : B

Question. To perform the initial setting time test, the water is added to the cement at the rate of .............. by weight of cement ?
a) 0.72 P
b) 0.78 P
c) 0.85 P
d) 0.95 P

Answer : C

Question. The addition surfactants in the concrete mix results in ?
a) decrease in the water cement ratio
b) increase in the strength of concrete
c) increase in the density of concrete
d) all of these

Answer : D

Question. The gypsum is added to the cement for ?
a) providing high strength to the cement
b) controlling the initial setting time of cement
c) lowering the clinkering temperature
d) all of the above

Answer : B

Question. Efflorescence in cement is caused due to the excess of ?
a) silica
b) lime
c) alkalies
d) iron oxide

Answer : C

Question. The Indian standard code specifies that the crushing strength for which the mix should be designed in the laboratory should be ................... the strength actually required ?
a) 1.25
b) 1.5
c) 2
d) 2.5

Answer : A

Question. Hydration of cement is due to the chemical action of water with ?
a) dicalcium silicate
b) tricalcium silicate
c) tricalcium aluminate
d) all of these

Answer : D

Question. The aggregates of .......... shape have maximum voids ?
a) irregular
b) angular
c) rounded
d) flaky

Answer : B

Question. The value of bulk density for angular and flaky aggregates is ............ as compared to graded aggregates ?
a) same
b) less
c) more
d) none

Answer : B

Question. For highly loaded columns, the concrete mix used is of proportion ?
a) 1:1:2
b) 1:1.5:3
c) 1:2:4
d) 1:3:6

Answer : A

Question. The slump test of concrete is used to measure ?
a) consistency
b) mobility
c) homogeneity
d) all of these

Answer : A

Question. The factor which effects the design of concrete mix is ?
a) fineness modulus
b) water-cement ratio
c) slump
d) all of these

Answer : D

Question. The test conducted in the laboratory on the specimen made out of trial ?
a) preliminary test
b) slump test
c) works test
d) none of these

Answer : A

Question. The object of compaction is to ?
a) eradicate air holes
b) give maximum density
c) ensure intimate contact between the concrete and the surface of reinforcement
d) all of the above

Answer : D

Question. The workability of concrete by slump test is expressed as ?
a) minutes
b) mm/h
c) mm²/h
d) mm

Answer : D

Question. When the walls are subjected to heavy loading and the bearing capacity of the soil is very low, then the wall is constructed on ?
a) reinforced concrete footing
b) column footing
c) lean concrete footing
d) none of these

Answer : A

Question. The type of lime used in lime concrete is ?
a) fat lime
b) poor lime
c) slaked lime
d) hydraulic lime

Answer : D

Question. The hardening is the phenomenon by virtue of which ?
a) the cement does not undergo large change in volume when treated with water
b) the plastic cement paste changes into hard mass
c) the cement paste sets and develops strength
d) none of the above

Answer : C

Question. In the manufacture of cement, the dry or wet mixture of calcareous and argillaceous materials burnt at a temperature between ?
a) 900°C to 1000°C
b) 1000°C to 1200°C
c) 1200°C to 1500°C
d) 1500°C to 1600°C

Answer : D

Question. Low percentage of tricalcium silicate and high percentage of dicalcium silicate in cement salts in ?
a) rapid hardening
b) high early strength
c) high heat generation
d) none of these

Answer : D

Question. The removal of excess air after placing concrete helps in increasing the strength of concrete by ?
a) 15 to 20%
b) 20 to 30%
c) 30 to 50%
d) 50 to 70%

Answer : A

Question. The aggregate which pass through 4.75 mm IS sieve and entirely retain on 75 micron IS sieve called ?
a) cyclopean aggregate
b) coarse aggregate
c) fine aggregate
d) all in aggregate

Answer : C

Question. The correct proportioning various ingredients of concrete largely depends upon ?
a) bulking of sand
b) water content
c) absorption
d) all of these

Answer : D

Question. The maximum particle size of fine aggregate is ?
a) 2.5 mm
b) 4.75 mm
c) 5.85 mm
d) 6.5 mm

Answer : B

Question. The aggregates of ............... shape have minimum voids ?
a) irregular
b) angular
c) rounded
d) flaky

Answer : D

Question. Plain cement concrete is strong in taking ?
a) tensile stress
b) compressive stress
c) shear stress
d) all of these

Answer : B

Question. PERT stands for ?
a) Programme Estimation and Reporting Technique
b) Process Estimation and Review Technique
c) Programme Evaluation and Review Technique
d) Planning Estimation and Resulting Technique

Answer : C

Question. Argillaceous materials contain ............ as their major constituent ?
a) calcium
b) lime
c) alumina
d) none

Answer : C

Question. If the slump of concrete mix is 70 mm, its workability is considered to be ?
a) very low
b) low
c) medium
d) high

Answer : C

Question. The admixtures are added in concrete to ?
a) accelerate the rate of setting and hardening of cement
b) make the concrete water proof, acid proof etc.
c) reduce the bleeding and segregation of concrete mix
d) all of the above

Answer : D

Question. Proper curing of cement concrete, is good for its ?
a) volume stability
b) strength
c) wear resistance
d) all of these

Answer : D

Question. With the moisture content of 5 to 10% by weight, the bulking of sand is increased by ?
a) 20%
b) 30%
c) 40%
d) 50%

Answer : D

Question. When the sand is fully saturated, its volume is ........ the volume of dry and loose sand ?
a) equal to
b) less than
c) more than
d) none of these

Answer : A

Question. After the final grinding, the cement is sieved through IS sieve number ?
a) 9
b) 12
c) 24
d) 48

Answer : A

Question. The main requirement, which a ware-house should fulfil is that ?
a) its walls should be water proof masonry construction
b) its roof should be leak
c) it must have large number of windows
d) its plinth should be very high

Answer : A

Question. The most useless aggregate is, whose surface texture is ?
a) smooth
b) glossy
c) granular
d) porous

Answer : B

Question. The apparent specific gravity of an aggregate is defined as ?
a) the weight of oven dry aggregate divided by its absolute volume, excluding the natural pores in the aggregate particles
b) the weight of oven dry aggregate divided by its absolute volume, including the natural pores in the aggregate particles
c) the weight of aggregate required to fill a container of unit volume
d) the difference in weight of the aggregate in saturated surface dry condition and in moist condition

Answer : A

Question. When the batching of material is done by weight ?
a) the bucket in which the material is to be weighed should be cleaned thoroughly
b) the weighing machine should be levelled before placing the material
c) the chart should be prepared indicating the weight of each material used for different strengths of concrete
d) all of the above

Answer : D

Question. Vertical sides of columns may be stripped after ?
a) 1 to 2 days
b) 7 days
c) 14 days
d) 21 days

Answer : A

Question. To perform the compressive strength test of cement, water is added at the rate of ?
a) 0.72 P+ 3% of water
b) 0.85 P+ 4% of water
c) P+ 3% of water
d) P+ 4% of water

Answer : C