MCQ  CONCRTE TECHNOLOGY

  1. The strength and durability of concrete depends on

(a)Size of aggregate(Ans)

(b)Grading of aggregate

(c)Moisture content of aggregate

(d)All of these

2.The breaking up of cohesion in a mass of concrete is called

(a)Workability

(b)Bleeding

(c)Segregation(Ans)

(d)Creep

3.The continuous strain, which the concrete undergoes due to application of external loads, is called

(a)Workability

(b)Bleeding

(c)Segregation

(d)Creep(Ans)

4.Harshness in concrete appears due to excess of

(a)Water

(b)Finer particle

(c)Middle size particle(Ans)

(d)Coarser particles

5.In case of lime concrete lime is used as

(a)Coarser aggregate

(b)Fine aggregate

(c)Binding material(Ans)

(d)admixture

6. In lime concrete the type of lime used is

(a)Fat lime

(b)Poor lime

(c)Slaked lime

(d)Hydraulic lime(Ans)

7.Ferro-concrete is another name given to

(a)Plain cement concrete

(b)Reinforced cement concrete(Ans)

(c)Prestressed cement concrete

(d)None of these

8. Reinforced cement concrete is equally strong in taking

(a)Tensile and compressive stress

(b)Compressive and shear stress

(c)Tensile ,compressive and shear stress(Ans)

(d)Tensile and shear stress

9. Plain cement concrete is strong for

(a)Tensile

(b)Compressive

(c)Shear

(d)All of these

10. In case of cement concrete in which high compressive stresses are artificially induced before its actual use

(a)Plain cement concrete

(b)Reinforced cement concrete

(c)Prestressed cement concrete(Ans)

(d)Lime concrete

11. For heat and sound insulation purpose, we will use

(a)Vacuum concrete

(b)Air entrained concrete(Ans)

(c)Saw dust concrete(Ans)

(d)Both a and b

12.The cement concrete from which entrained air and excess water are removed after placing it in position is called

(a)Vacuum concrete(Ans)

(b)Light weight concrete

(c)Prestressed concrete

(d)Sawdust concrete

13.The removal of excess air after placing concrete helps in increasing the strength of concrete by

(a)15 to 20%Ans)

(b)20 to 30%

(c)30 to 50%

(d)50 to 70%

14.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(Ans)

15.Light weight concrete is prepared by

(a)Mixing Portland cement with sawdust in specified proportion in the concrete

(b(Using coke breeze, cinder or slag as aggregate in the concrete(Ans)

(c)Mixing aluminium in the concrete

(d)None of the above

16.Construction of precast structural units for partition and wall lining purposes, the concrete should be

(a)Sawdust concrete

(b)Air entrained concrete

(c)Light weight concrete(Ans)

(d)Vacuum concrete

17.A suitable admixture added at the time of preparing the concrete mix , makes the concrete

(a)Water proof

(b)Acid proof

(c)Highly strong

(d)All of these(Ans)

18.The function of aggregate in concrete is to serve as

(a)Binding material

(b)Filler(Ans)

(c)Catalyst

(d)All of these

19.Calcareous material used in the manufacture of cement consists of

(a)Lime stone

(b)Chalk

(c)Shells

(d)All of these(Ans)

20.In the manufacture of concrete, the dry or wet mixture of calcareous argillaceous materials is burnt and in a

(a)Country kiln

(b)Continuous flare kiln

(c)Rotary kiln (Ans)

(d)All of these

  1. In the manufacture of concrete, the dry or wet mixture of calcareous argillaceous materials is burnt at a temperature between

(a)900oC to 1000oC

(b)1000oC to 1200oC

(c)1200oC to 1500oC (Ans)

(d)1500oC to 1600oC (Ans)

 

  1. Argillaceous materials contain……..as their major constituent.

(a)Calcium

(b)Lime

(c)Alumina (Ans)

  1. Hydration of cement evolves heat.

(a)True (Ans)

(b)False

  1. The proportion of lime, silica, alumina and iron oxide in a good Portland cement should be

(a)63 : 22 : 6 : 3 (Ans)

(b)63 : 22 : 3 : 6

(c)22 : 63 : 6 : 3

(d)63 : 22 : 3 : 6

  1. The chemical ingredient of cement which provides quick setting property to the cement is

(a)Lime (Ans)

(b)Silica

(c)Alumina

(d)Iron oxide

26.The presence of lime in cement

(a)Makes the cement sound (Ans)

(b)Provides strength to the cement (Ans)

(c)Lowers the clinkering temperature

(d)All of these

  1. Which of the following ingredient of cement when added in excess quantity, causes the cement to set slowly ?

(a)Lime

(b)Silica (Ans)

(c)Alumina

(d)Iron oxide

  1. In order to provide colour, hardness and strength to the cement, the ingredient used is

(a)Lime

(b)Silica

(c)Alumina

(d)Iron oxide (Ans)

  1. After the final grinding, the cement is sieved through IS sieve number

(a)9

(b)12

(c)24

(d)48

  1. Efflorescence in cement is caused due to the excess of

(a)Silica

(b)Lime

(c)Alkalies (Ans)

(d)Iron oxide

  1. The presence of tricalcium silicate in cement

(a)Hydrates the cement rapidly (Ans)

(b)Generates less heat of hydration

(c)Offers high resistance to sulphate attack

(d)All of these

  1. The presence of tricalcium silicate in cement

(a)Hydrates the cement rapidly (Ans)

(b)Generates less heat of hydration

(c)Offers high resistance to sulphate attack

(d)All of these (Ans)

  1. The tricalcium aluminate in cement has the property of

(a)Reacting fast with water

(b)Causing initial setting of cement

(c)Generating large amount of heat hydration

(d)All of these (Ans)

  1. High percentage of tricalcium silicate and low percentage of dicalcium silicate in cement results in

(a)Rapid hardening

(b)High early strength

(c)Highheat generation

(d)All of these (Ans)

  1. Low percentage of tricalcium silicate and high percentage of dicalcium silicate in cement results in

(a) Rapid hardening

(b)High early strength

(c)  Highheat generation

(d)none of these (Ans)

  1. The sum of percentage of tricalcium silicate and dicalcium silicate for Portland cement varies from

(a)50 to 60 %

(b)60 to 70 %

(c)70 to 80 % (Ans)

(d)80 to 90 %

  1. Rapid hardening cement is used

(a)Where high early strength is desired

(b)Where form work is to be removed as early as possible

(c)For constructing road pavements

(d)All of the above (Ans)

  1. Low heat cement is used in………………structures.

(a)Thin

(b)Thick (Ans)

  1. The cement, widely used in retaining walls, is

(a)Rapid hardening cement

(b)Low heat cement (Ans)

(c)Sulphate resisting cement

(d)Ordinary Portland cement

  1. Blast furnace slag cement is used for

(a)Dams

(b)Bridge abutments

(c)Retaining walls

(d)All of these (Ans)

  1. Blast furnace slag cement concrete requires…………………..time for shuttering and curing.

(a)Less

(b)More (Ans)

42.Blast furnace slag cement concrete

(a)Develops low heat of hydration (Ans)

(b)Has less early strength (Ans)

(c)Develops high heat of hydration

(d)Has high early strength

  1. Which of the following cements is expected to have the highest compressive strength after 3 days ?

(a)Ordinary Portland cement

(b)Rapid hardening cement

(c)High alumina cement (Ans)

(d)Sulphate resisting cement

  1. For a structure subjected to the action of sea water, the cement used is

(a)     Rapid hardening cement

(b)     low heat cement

(c)      high alumina cement (Ans)

(d)        Sulphate resisting cement

45.The strength of concrete using air entraining cement gets reduced by

 

(a)5 to 10 %

(b)10 to 15 % (Ans)

(c)15 to 20 %

(d)20 to 25 %

46.“Colocrete” is the commercial term for

(a)High alumina cement

(b)Coloured cement (Ans)

(c)Low heat cemenet

(d)Rapid hardening cement

47.Pozzolana is essentially a silicious material containing clay upto

(a)20 %

(b)40 %

(c)60 %

(d)80 % (Ans)

48.In the manufacture of pozzolana cement, the amount of pozzolana material added to ordinary Portland cement clinkers is about

(a)20 %

(b)30 % (Ans)

(c)40 %

(d)50 %

49.The degree of grinding of cement is called

(a)Fineness (Ans)

(b)Soundness

(c)Impact value

(d)Bulking

50.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 (Ans)

(d)None of the above

51.The phenomenon by virtue of which the cement does not undergo large change in volume when treated with water, is known as

(a)Fineness

(b)Soundness (Ans)

(c)Setting time

(d)None of these

52.Too much fineness of cement

(a)Results cracks in concrete

(b)Generates greater heat

(c)Develops early strength

(d)Both (a) and (b) (Ans)

53.The setting time of cement is the governing factor for

(a)Mixing of concrete

(b)Placing of concrete

(c)Compacting of concrete

(d)All of these (Ans)

54.Vicat apparatus is used to perform

(a)Fineness test

(b)Soundness test

(c)Consistency test(Ans)

(d)Compressive strength test

55.The percentage of water for making a cement paste of normal consistency varies from

(a)15 to 25 %

(b)25 to 35%(Ans)

(c)35 to 50%

(d)50 to 60%

56.To perform the initial setting time test, the water is added to the cement at the rate of ……. By weight of cement

(a)72P

(b)78P

(c)85P(Ans)

(d)95P

57.Le-Chatelier apparatus is used to perform

(a)Fineness test

(b)Soundness test(Ans)

(c)Consistency test

(d)Compressive strength test

58.To perform the compressive strength test of cement, water is added at the rate of

(a)72P+3% of water

(b)85P+4% of water

(c)P+3% of water(Ans)

(d)P+4% of water

59.Initial setting time of ordinary Portland cement

(a)15 min

(b)30 min(Ans)

(c)60 min

(d)600 min

60.The cube of cement prepared for compressive strength test should be kept at a temperature of …….. in an atmosphere of at least 90% relative humidity for 24 hours

(a)15O+_2O C

(b)21O+_2O C

(c)27O+_2O C(Ans)

(d)30O+_2O C

61.The inert mineral material used for the manufacture of mortars and concretes is

(a)Cement

(b)Water

(c)Aggregate(Ans)

(d)Admixture

62.The material having particle size varying from 0.002 to 0.06 mm is termed as

(a)Silt(Ans)

(b)Clay

(c)Sand

(d)None of these

63.The aggregate which passes through 75 mm IS sieve and entirely retain on 4.75 mm IS sieve is known as

(a)Cyclopean aggregate

(b)Coarse aggregate(Ans)

(c)Fine aggregate

(d)All in aggregate

64.The maximum size of coarse aggregate

(a)45 mm

(b)55mm

(c)65mm

(d)75mm(Ans)

65.The maximum particle size of fine aggregate is

(a)5mm

(b)75mm(Ans)

(c)85mm

(d)5mm

66.The maximum particle size of coarse aggregate

(a)5 mm

(b)75mm(Ans)

(c)85mm

(d)5mm

67.The minimum particle size of fine aggregate is

(a)0.0075 mm

(b)0.075mm(Ans)

(c)0.75mm

(d)0.95mm

68.The aggregates ………. Shape have minimum voids

(a)Irregular

(b)Angular

(c)Rounded(Ans)

(d)Flaky

69.The aggregates of………….. shape have maximum voids

(a)Irregular

(b)Angular(Ans)

(c)Rounded

(d)Flaky

70.The aggregate is said to be flaky when

(a)Its least dimension is three – fifth of its mean dimension(Ans)

(b)Its lest dimension is equal to its mean dimension

(c)Its length is equal to its mean dimension

(d)Its length is equal to 1.8 times its mean dimension

71.The aggregate is said to be elongated when

(a)Its least dimension is three – fifth of its mean dimension

(b)Its lest dimension is equal to its mean dimension

(c)Its length is equal to its mean dimension

(d)Its length is equal to 1.8 times its mean dimension(Ans)

72.If the aggregate completely passes through a 50 mm sieve and retained on 40 mm sieve, then the particular aggregate is said to be flaky if its least dimension is less than

(a)27mm (Ans)

(b)37mm

(c)47mm

(d)57mm

73.The value of the bulk density of aggregates is depends upon

(a)Size distribution of aggregate

(b)Shape of aggregate

(c)Specific gravity of aggregate

(d)All of these(Ans)

74.An aggregate which may contain moisture in the pores but having dry surface is known as

(a)Very dry aggregate

(b)Dry aggregate(Ans)

(c)Saturated surface dry aggregate

(d)Moist aggregate

75. An aggregate having all the pores filled with water but having dry surface is called

(a)Very dry aggregate

(b)Dry aggregate(Ans)

(c)Saturated surface dry aggregate

(d)Moist aggregate

  1. The sum of percentage of all deleterious materials in the aggregate shall not exceed

(a) 5% (Ans)

(b) 10%

(c) 15%

(d) 20%

  1. The resistance of an aggregate to compressive forces is known as

(a) crushing value(Ans)

(b) impact value

(c) abrasion value

(d) none of these

  1. The resistance of an aggregate to wear is known as

(a) crushing value(Ans)

(b) impact value

(c) abrasion value

(d) soundness(Ans)

  1. Bulking of sand is

(a) compacting of sand

(b) segregating sand of particular size

(c) increase in volume of sand due to presence of moisture upto certain extent(Ans)

(d) none of these

  1. 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%(Ans)

  1. The ratio of the volume of moist sand to the volume of dry sand is known as

(a) crushing value

(b) impact value

(c) bulking factor (Ans)

(d) none of these

  1. Fine sand bulks………………..than coarser sand.

(a) less

(b) more (Ans)

  1. The fineness modulus of an aggregate is roughly proportional to

(a) specific gravity of the aggregate

(b) shape of the aggregate

(c) average size of particles in the aggregate (Ans)

(d) grading of the aggregate

  1. The coarser the aggregate, the……………..is the fineness modulus

(a) higher

(b) lower (Ans)

  1. The value of fineness modulus for fine sand may range between

(a) 1.1 to 1.3

(b) 1.3 to 1.6

(c) 1.6 to 2.2

(d) 2.2 to 2.6 (Ans)

  1. If the fineness modulus of sand is 3, then the sand is graded as

(a) very fine sand

(b) fine sand

(c) medium sand

(d) coarse sand (Ans)

  1. The presence of………………..in water has an adverse effect on the setting time of concrete

(a) sodium carbonate and bicarbonate (Ans)

(b) calcium chloride

(c) sodium chloride

(d) sodium sulphate

  1. The presence of calcium chloride in water

(a) accelerates setting of cement (Ans)

(b) accelerates hardening of cement (Ans)

(c) causes little effect on quality of concrete

(d) all of these

  1. If sea water is used for preparing concrete mix, it

(a) reduces strength

(b) corrodes steel reinforcement

(c) causes efflorescence

(d) all of these (Ans)

  1. The standard sand now used in India is obtained from

(a) ennore (Chennai) (Ans)

(b) Mumbai

(c) Orissa

(d) jaipur

  1. Insufficient quantity of water

(a) makes the concrete mix harsh (Ans)

(b) makes the concrete mix unworkable (Ans)

(c) causes segregation  in concrete

(d) causes bleeding  in concrete

  1. Excess quantity of water

(a) makes the concrete mix harsh

(b) makes the concrete mix unworkable

(c) causes segregation  in concrete (Ans)

(d) causes bleeding  in concrete (Ans)

  1. Water cement ratio may be defined as the ratio of

(a) volume of water to that of cement in a concrete mix (Ans)

(b) weight  of water to that of cement in a concrete mix (Ans)

(c) volume of water to that of concrete in a concrete mix

(d) weight  of water to that of concrete in a concrete mix

  1. The rule of water cement ratio was established by

(a) Duff Abram (Ans)

(b) Plowman

(c) W. Simms

(d) Dr. Karl Terzaghi

  1. 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 (Ans)

(d) all of the above

  1. The strength of cement concrete increases with the increase of water cement ratio.

(a) agree

(b) disagree (Ans)

  1. The cement concrete having water-cement ratio less than 0.45 by weight, causes honey-comb structure.

(a) correct (Ans)

(b) incorrect

  1. 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 (Ans)

  1. The development of first 28 days strength is on account of the hydration of

(a) dicalcium silicate

(b)  tricalcium silicate (Ans)

(c) tricalcium aluminate

(d) tetra calcium alumino ferrite

  1. If the water cement ratio 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(Ans)

  1. The concrete mix is sais to be workable if it has

(a) compatibility

(b) movability

(c) stability

(d) all of these(Ans)

  1. For the improvement of workability of concrete , the shape of aggregate recommended is

(a) irregular

(b) angular

(c) rounded(Ans)

(d) flaky

  1. The use of air entraining agent in concrete

(a) increase workability of concrete

(b) decrease bleeding

(c) decrease strength

(d) all of these(Ans)

  1. The workability of concrete can be improved by adding

(a) hydrated lime

(b) fly ash

(c) calcium chloride

(d) all of these(Ans)

  1. For high degree of workability , the slump value should be

(a) 0 to 25 mm

(b) 25 to 50 mm

(c) 50 to 80 mm

(d) 80 to 100 mm(Ans)

  1. For higher degree of workability , the compaction factor is

(a) 0.65

(b) 0.75

(c) 0.85

(d) 0.95(Ans)

  1. Workability of concrete mix having very low water –cement ratio should be obtained by

(a) flexural strength test

(b) slump test

(c) compaction factor test(Ans)

(d) any of these

  1. The slump test in concrete is used to measure it

(a) consistency(Ans)

(b) mobility

(c) homogeneity

(d) all of these

  1. The test conducted in the laboratory on the specimen made out of trial concrete mix is called

(a) preliminary test(Ans)

(b) slump test

(c) works test

(d) none of these

  1. The preliminary test should be repeated if the difference of compressive strength of three test specimen exceeds

(a) 0.5 N/mm2

(b) 1 N/mm2

(c) 1.5 N/mm2(Ans)

(d) 2 N/mm2

  1. For mass concrete in piers and abutments , the grade of concrete mix used is

(a) 1:1:2

(b) 1:1.5:3

(c) 1:2:4

(d) 1:3:6(Ans)

  1. For highly loaded columns, the concrete mix should be used

(a) 1:1:2(Ans)

(b) 1:1.5:3

(c) 1:2:4

(d) 1:3:6

  1. IF 30% excess water is added, the strength of the concrete reduced by

(a) 30%

(b) 40%

(c) 50%(Ans)

(d) 60%

  1. The concrete in which preliminary tests are performed for designing the mix is called

(a) rich concrete

(b) controlled concrete(Ans)

(c) lean concrete

(d) ordinary concrete

  1. The maximum quantity of aggregate per 50 kg of cement should not exceed

(a) 100 kg

(b) 200 kg

(c) 350 kg

(d) 450 kg(Ans)

  1. The concrete in which no preliminary tests are performed for designing the mix is called

(a) rich concrete

(b) controlled concrete

(c) lean concrete

(d) ordinary concrete(Ans)

  1. For reinforced cement concrete lintels and slabs , the nominal size of coarse aggregate should not exceed

(a) 10mm

(b) 15 mm(Ans)

(c) 20mm

(d) 40mm

  1. The process of proper and accurate measurement of all concrete materials for uniformity of proportions and aggregate grading is called

(a) proportioning

(b) grading

(c) mixing

(d) batching(Ans)

  1. The process of mixing, transporting, placing and compacting the cement concrete should not take more than

(a) 30 min(Ans)

(b) 60 min

(c) 90 min

(d) 120 min

  1. The concrete can be lifted by pumps through a maximum vertical distance of

(a) 10m

(b) 20m

(c) 30m

(d) 50m(Ans)

  1. The diameter of the pipe line used for transportation of concrete by pumps should not exceed

(a) 10 cm

(b) 20 cm

(c) 30 cm (Ans)

(d) 40 cm

  1. To prevent segregation, the concrete should not be thrown from height of more than

(a) ½ m

(b) 1 m (Ans)

(c) 1.5 m

(d) 2 m

  1. The process of consolidating concrete mix after placing it in position is termed as

(a) curing

(b) wetting

(c) compaction (Ans)

(d) none of these

  1. When the concrete mix is too wet, it causes

(a) segregation

(b) low density

(c) excess laitance at the top

(d) all of these (Ans)

  1. The factor which effect the quality of compaction, is

(a) density of concrete

(b) strength of concrete

(c) durability of concrete

(d) all of these (Ans

  1. For compacting large sections of mass concrete in structures, the type of vibrator used is

(a) internal vibrator (Ans)

(b) screed vibrator

(c) form vibrator

(d) all of these

  1. For compacting plain concrete or one-way reinforced concrete floors, the vibrator used as

(a) internal vibrator

(b) screed vibrator (Ans)

(c) form vibrator

(d) all of these

  1. The levelling operation that removes humps and hollows and give a true, uniform concrete surface is called

(a) screeding (Ans)

(b) floating

(c) trowelling

(d) compacting

  1. The final operation of finishing the concrete surface is called

(a) screeding

(b) floating

(c) trowelling (Ans)

(d) none of these

  1. The process of hardening the concrete mixes by keeping its surface moist for a certain period is called

(a) floating

(b) curing (Ans)

(c) screeding

(d) none of these

  1. After the curing of 28 days, the concrete gains strength upto

(a) 40 %

(b) 67 %

(c) 100 % (Ans)

(d)  122 %

  1. Proper curing of cement concrete, is good for its

(a) volume stability

(b) strength

(c) wear resistance

(d) all of these (Ans)

  1. Under normal circumstances, the beam soffits may be removed after

(a) 2 days

(b) 7 days (Ans)

(c) 14 days

(d) 21 days

  1. Vertical sides of columns may be stripped after

(a) 1 to 2 days (Ans)

(b) 7 days

(c) 14 days

(d) 21 days

  1. In concrete walls, construction joints should be provided at the

(a) floor level

(b) soffit level of lintels

(c) sill level of windows

(d) all of these (Ans)

  1. The construction joints are generally provided concrete

(a) roads

(b) retaining walls

(c) lining of tunnels

(d) all of these (Ans)

  1. The most useless aggregate is, whose surface texture is

(a) smooth

(b) glossy (Ans)

(c) granular

(d) porous

  1. The bulk density of aggregates depends upon its

(a) shape

(b) grading

(c) compaction

(d) all of these (Ans)