Civil Engineering Competitive Questions
Select the incorrect statement
[ A ] R.C.C has better fire resistance than steel [ B ] R.C.C. structure is economical than steel structure [ C ] Strength of concrete decreases as age increases [ D ] R.C.C can be used for under water and marine structuresAnswer : C
3 Water cement ratio is the ratio of
[ A ] Water to cement by weight [ B ] Water to cement by volume [ C ] Cement to water by weight [ D ] Cement to water by volumeAnswer : A
4 Concrete is
[ A ] Weak in tension [ B ] Strong in tension [ C ] Strong in both tension and compression [ D ] Weak in compressionAnswer : A
5 The entrained air in concrete
[ A ] Increases the strength [ B ] Decreases the resistance to weathering [ C ] Increases the workability [ D ] Decreases the workabilityAnswer : C
6 Concrete is unsuitable for compaction by vibration if it is
[ A ] Semi – plastic [ B ] Plastic [ C ] Earth moist [ D ] DryAnswer : B
7 The strength and quality of concrete depends upon
(i)Grading of aggregates
(ii)Shape of aggregates
(iii)Surface area of aggregates
(iv)Surface texture of aggregates
[ A ] i, ii and iv [ B ] ii, iii and iv [ C ] i, iii and iv [ D ] i, ii, iii and ivAnswer : D
8 In order to avoid segregation, fresh concrete should be dropped from a height of
[ A ] Less than one meter [ B ] Less than two metres [ C ] More than one metre [ D ] More than two metresAnswer : A
9 The process of hardening of concrete in the presence of water is called
[ A ] Creep [ B ] Hydration [ C ] Shrinkage [ D ] CuringAnswer : B
10 The process of keeping the concrete structure moist is called
[ A ] Hydration [ B ] Curing [ C ] Creep [ D ] ShrinkageAnswer : B
11 The separation of water or water cement mixture from the freshly laid concrete is known as
[ A ] Workability [ B ] Segregation [ C ] Bleeding [ D ] CreepAnswer : C
12 The continuous strain, which the concrete undergoes due to application of external loads is
called
[ A ] Creep [ B ] Bleeding [ C ] Workability [ D ] SegregationAnswer : A
13 The process of conversion of plastic concrete to solid stage is called
[ A ] Hydration [ B ] Hardening [ C ] Setting [ D ] CuringAnswer : C
14 At 28 days of curing concrete attains a strength of
[ A ] 20 to 25% [ B ] 60 to 70% [ C ] 65 to 80% [ D ] 90 to 95%Answer : D
15 In a mass concrete, the aggregates occupy a space of
[ A ] 25% [ B ] 75% [ C ] 40% [ D ] 60%Answer : B
16 The coarse aggregate which possess the property of good interlocking are
[ A ] rounded shape [ B ] elongated shape [ C ] angular shape [ D ] none of the aboveAnswer : C
17 While placing of concrete the thickness of each layer for R.C.C. is
[ A ] 150 to 300 mm [ B ] 450 mm [ C ] 500 to 750 mm [ D ] 500 mmAnswer : A
18 Increase in water content in a cement concrete
(i) Increases workability
(ii) Increases the strength
[ A ] i [ B ] ii [ C ] both (i) and (ii) [ D ] neither (i) nor (ii)Answer : A
19 Slump cone test is used to determine
[ A ] Shrinkage of concrete mix [ B ] Creep of concrete [ C ] Workability of concrete mix [ D ] Soundness of concreteAnswer : C
20 While determining the workability of concrete mix, the compaction factor test is ——than the
slump cone test
[ A ] Less accurate [ B ] More accurate [ C ] Approximate method [ D ] None of the aboveAnswer : B
21 Workability of concrete mix with low water cement ratio is determined by
[ A ] Tensile strength test [ B ] Slump cone test [ C ] Compaction factor test [ D ] Flexural strength testAnswer : C
22 If the slump of a concrete mix is 50 to 100 mm, its workability is
[ A ] Very low [ B ] Low [ C ] Medium [ D ] HighAnswer : C
23 A compaction factor of 0.75 indicates ________workability
[ A ] Very low [ B ] Low [ C ] Medium [ D ] HighAnswer : A
24 Shrinkage in concrete can be reduced by using
(i) Low water cement ratio (ii) More amount of cement in the concrete
(iii) Presaturated aggregates
[ A ] i [ B ] i and ii [ C ] i and iii [ D ] i, ii and iiiAnswer : C
25 The process of proper and accurate measurement of concrete ingredients for uniformity of
proportion, is known as
[ A ] Curing [ B ] Mixing [ C ] Grading [ D ] BatchingAnswer : D
26 Select incorrect statement from the following
[ A ] With passage of time, the strength of cement decreases [ B ] With passage of time, the strength of cement increases [ C ] After a period of 24 months, the strength of cement reduces to 50% [ D ] The concrete made with storage deteriorated cement; gains strength with time.Answer : B
27 For compacting plain concrete road surface of thickness less than 20 cm, the following
vibrator is used.
[ A ] Internal vibrator [ B ] Screed vibrator [ C ] Form vibrator [ D ] None of the aboveAnswer : B
28 Slump test of concrete is a measure of its
[ A ] Consistency [ B ] Compressive strength [ C ] Tensile strength [ D ] Impact valueAnswer : A
29 Concrete gains strength due to
[ A ] Chemical reaction of cement with sand and coarse aggregates [ B ] Evaporation of water from concrete [ C ] Hydration of cement [ D ] All the aboveAnswer : C
30 Minimum grade of concrete for R.C.C. should be _________ , as per IS. 456-2000
[ A ] M10 [ B ] M14 [ C ] M20 [ D ] M25Answer : C
31 A concrete mass containing 5% of voids
[ A ] Increases its strength by 30% [ B ] Reduces its strength by 30% [ C ] Increases its strength by 5% [ D ] Reduces its strength by 5%Answer : B
32 Workability of a concrete – mix is determined by
(i)Slump cone test
(ii)Compaction factor test
(iii)Vee bee test
[ A ] i [ B ] ii [ C ] i and ii [ D ] i, ii and iiiAnswer : D
33 High strength of concrete requires a water cement ratio of
[ A ] 0.10 to 0.15 [ B ] 0.25 to 0.30 [ C ] 0.45 to 0.60 [ D ] 0.75 to 0.90Answer : B
34 One bag of cement is equivalent to
[ A ] 50 litres [ B ] 35 litres [ C ] 28 litres [ D ] 14 litresAnswer : B
35 One cubit metre of cement weights
[ A ] 1000 kg [ B ] 1200 kg [ C ] 1440 kg [ D ] 1600 kgAnswer : C
36 As per IS: 456-2000, modulus of elasticity of concrete (in N/mm2) is given by
[ A ] 5700 vfCK [ B ] 5000 vfCK [ C ] 3700 vfCK [ D ] 3000 vfCKAnswer : B
37 In working stress method of design, the factor of safety for concrete and steel respectively
are
[ A ] 3.0 and 1.8 [ B ] 3.0 and 1.18 [ C ] 3.0 and 1.15 [ D ] 1.5 and 1.5Answer : A
38 In Limit state method of design, the factor of safety for concrete and steel respectively are
[ A ] 3.00 and 1.80 [ B ] 1.50 and 1.18 [ C ] 1.50 and 1.15 [ D ] 1.50 and 1.50
Answer : C
39 Specific weight of Reinforced cement concrete is
[ A ] 24 N/m3 [ B ] 24 kN/m3 [ C ] 25 N/m3 [ D ] 25 kN/m3Answer : D
40 The tensile strength of concrete is about ________ of its compressive strength
[ A ] 10% to 15% [ B ] 30% to 40% [ C ] 50% [ D ] 60% to 75%Answer : A
41 The shrinkage strain of concrete is generally taken as
[ A ] 0.3 [ B ] 0.03 [ C ] 0.003 [ D ] 0.0003Answer : D
42 The tensile strength of concrete is given by
[ A ] 0.45 vfCK [ B ] 0.60 vfCK [ C ] 0.70 vfCK [ D ] 0.90 vfCKAnswer : C
43 The ratio of bond stress for HYSD bars to that of plain bars
[ A ] 0.714 [ B ] 0.9 [ C ] 1.4 [ D ] 1.8Answer : C
44 The proof stress in steel is the stress corresponding to the strain of
[ A ] 0.2 [ B ] 0.02 [ C ] 0.002 [ D ] 0.0002Answer : C
45 In the mixer, the concrete should be mixed for at least
[ A ] 1 to 2 minutes [ B ] 2 to 3 minutes [ C ] 3 to 5 minutes [ D ] 5 to 7 minutesAnswer : B
46 As per IS: 456-2000, the maximum size of aggregate is
[ A ] 1/4 of maximum thickness of member [ B ] 1/4 of minimum thickness of member [ C ] 1/5 of maximum thickness of member [ D ] 1/5 of minimum thickness of memberAnswer : B
47 Water used for mixing of concrete should be free from
(i)Oils
(ii)Salts
(iii)Acids
[ A ] i [ B ] iii [ C ] i and iii [ D ] i, ii and iiiAnswer : D
48 Modulus of elasticity of concrete is primarily influenced by
[ A ] Elastic properties of aggregate [ B ] Curing of concrete [ C ] Age of concrete [ D ] Mix proportion and type of cementAnswer : A
49 As the workability increases compaction factor
[ A ] Decreases [ B ] Increases [ C ] Remains same [ D ] None of the aboveAnswer : B
50 Shrinkage of concrete is mostly influenced by
[ A ] Environmental conditions [ B ] Size of member [ C ] Cement in concrete [ D ] The total amount of water present in concreteAnswer : D
51 During the process of hardening of cement, _______ will takes place
[ A ] Bleeding [ B ] Segregation [ C ] Hydration [ D ] All the aboveAnswer : C
52 Due to Bleeding action concrete becomes
[ A ] Weak [ B ] Strong [ C ] Hard [ D ] DurableAnswer : A
53 About 70% to 80% of cement is contributed by
[ A ] Tricalcium silicate and Tricalcium aluminate [ B ] Tricalcium silicate and Dicalcium silicate [ C ] Tricalcium Aluminate and Dicalcium silicate [ D ] Tricalcium Aluminate and Tetra calcium AluminoferriteAnswer : B
54 When compared to ordinary Portland cement, Rapid hardening Portland cement contains
______________ amount of lime content
[ A ] Equal [ B ] Greater [ C ] Lesser [ D ] ZeroAnswer : B
55 The following compound has the property of early strength as well as ultimate strength
[ A ] C3S [ B ] C2S [ C ] C3A [ D ] C4AFAnswer : A
56 Which of the following compounds is considered to be an undesirable compound for cement
[ A ] C3S [ B ] C2S [ C ] C3A [ D ] C4AFAnswer : D
57 Which of the following compound is susceptible to be attached by alkalies and salts
[ A ] C3S [ B ] C3S [ C ] C3A [ D ] C3AFAnswer : C
58 The heat generated in ordinary cement at the end of 3 days is about
[ A ] 60 cal/g [ B ] 80 cal/g [ C ] 100 cal/g [ D ] 120 cal/gAnswer : B
59 Low heat cement contains more amount of __________ than that of ordinary Portland
cement
[ A ] C3S [ B ] C2S [ C ] C3A [ D ] None of the aboveAnswer : B
60 In Portland Blast furnace slag cement, the blast furnace slag content shall not exceed
[ A ] 50% [ B ] 65% [ C ] 80% [ D ] 90%Answer : B
61 White cement contains less amount of ___________
[ A ] Lime [ B ] Silica [ C ] Alumina [ D ] Iron oxideAnswer : D
62 In fineness test on cement, residue left on I.S. sieve no.9 shall not exceed __________ by
weight of the sample of cement
[ A ] 5% [ B ] 10% [ C ] 15% [ D ] 20%Answer : B
63 Ordinary Portland cement requires a specific surface of
[ A ] 1250 cm2/gm [ B ] 2250 cm 2/gm [ C ] 3250 cm 2/gm [ D ] 3500 cm 2/gmAnswer : B
64 The maximum percentage of chemical ingredient of cement is
[ A ] Iron oxide [ B ] Silica [ C ] Lime [ D ] Magnesium oxideAnswer : C
65 The minimum percentage of chemical ingredient of cement is
[ A ] Iron oxide [ B ] Silica [ C ] Lime [ D ] Magnesium oxideAnswer : D
66 Efflorescence in cement is caused due to an excess of
[ A ] Alkalies [ B ] Silica [ C ] Iron oxide [ D ] AluminaAnswer : A
67 Dicalcium silicate (C2S)
[ A ] rates rapidly [ B ] Hardens rapidly [ C ] Generates less heat of hydration [ D ] Has less resistance to sulphate attackAnswer : C
68 Tricalcium aluminate (C3A)
[ A ] Hydrating less rapidly [ B ] Is a redundant compound [ C ] To be attacked by alkalies and salts [ D ] None of theseAnswer : C
69 For road pavements, the cement generally used, is
[ A ] Ordinary Portland cement [ B ] Rapid hardening cement [ C ] Low heat cement [ D ] Blast furnace slag cementAnswer : A
70 For mass concrete work, the type of cement preferable is
[ A ] Ordinary Portland cement [ B ] Rapid hardening cement [ C ] Low heat cement [ D ] Blast furnace slag cementAnswer : C
71 Le-chatelier apparatus is used for
[ A ] Fineness test [ B ] Consistency test [ C ] Soundness test [ D ] Compressive strength testAnswer : C
72 The diameter of the Vicat plunger is 10 mm and its length varies form
[ A ] 40 mm [ B ] 50 mm [ C ] 55 mm [ D ] 60 mmAnswer : B
73 Inert material of a cement concrete mix, is
[ A ] Water [ B ] Aggregate [ C ] Cement [ D ] None of theseAnswer : B
74 An aggregate is said to be flaky, if its least dimension is less than
[ A ] 2/3 mean dimension [ B ] 3/4 mean dimension [ C ] 3/5 mean dimension [ D ] 5/8 mean dimensionAnswer : C
75 Workability of concrete for a given water content is good, if the aggregates are
[ A ] Rounded [ B ] Irregular [ C ] Angular [ D ] FlakyAnswer : A
76 Setting time of cement increases by adding
(i)gypsum
(ii)sodium oxide
(iii)calcium chloride
[ A ] i [ B ] i and ii [ C ] i and iii [ D ] i, ii and iiiAnswer : A
77 The cement becomes useless if its absorbed moisture content exceeds
[ A ] 1% [ B ] 2% [ C ] 3% [ D ] 5%Answer : D
78 The size of fine aggregates does not exceed
[ A ] 2.75 mm [ B ] 3.75 mm [ C ] 4.75 mm [ D ] 5.75 mmAnswer : C
79 Water used for mixing concrete should be
[ A ] Slightly acidic [ B ] Free from bacteria [ C ] Distilled [ D ] PotableAnswer : D
80 The workability of concrete is mostly influenced by its
[ A ] Water cement ratio [ B ] Aggregate cement ratio [ C ] Cement content [ D ] Water contentAnswer : A
81 Chief constituent of ordinary Portland cement is
[ A ] Lime [ B ] Alumina [ C ] Magnesia [ D ] Iron oxideAnswer : A
82 The heat of hydration for low heat cement at the age of 7 days shall not exceed
[ A ] 80 cal / gm [ B ] 75 cal / gm [ C ] 70 cal / gm [ D ] 65 cal / gmAnswer : D
83 Cement is obtained by burning a mixture of the following materials
[ A ] Siliceous materials [ B ] Argillaceous materials [ C ] Calcareous materials [ D ] All the aboveAnswer : D
84 For determining the compressive strength test on cement is, the percentage amount of
water to be added as (Pa = Percentage of water for required consistency)
[ A ] 0.25 Pa + 2.5 [ B ] 0.25 Pa + 3.5 [ C ] 0.35 Pa + 2.5 [ D ] 0.35 Pa + 3.5Answer : B
85 Minimum compressive strength of cement required at the age of 3 days for ordinary
Portland cement of grade 33 is
[ A ] 1.15 N/mm2 [ B ] 11.5 N/mm2 [ C ] 2.10 N/mm2 [ D ] 21 N/mm2Answer : B
86 Bulking of sand takes place due to
[ A ] Surface tension [ B ] Viscosity [ C ] Capillarity [ D ] None of the aboveAnswer : A
87 Creep coefficient is the ratio of
[ A ] Ultimate Creep strain to elastic strain [ B ] Elastic strain to ultimate Creep strain [ C ] Elastic strain to plastic strain [ D ] Plastic strain to elastic strainAnswer : A
88 Generally the strength of concrete is represented by the crushing stress of concrete cube of
size
[ A ] 50 mm [ B ] 100 mm [ C ] 150 mm [ D ] 250 mmAnswer : C
89 As per IS:1139, the characteristic yield strength for hot rolled High yield strength deformed
bars is
[ A ] 250 N/mm2 [ B ] 415 N/mm2 [ C ] 500 N/mm2 [ D ] 550 N/mm2Answer : B
90 As per IS:1139, the characteristic yield strength for cold twisted deformed bars is
[ A ] 250 N/mm2 [ B ] 415 N/mm2 [ C ] 500 N/mm2 [ D ] 550 N/mm2Answer : C
91 For reinforced concrete work, aggregates having a nominal size of ——– are generally used
[ A ] 20 mm [ B ] 40 mm [ C ] 50 mm [ D ] 60 mmAnswer : A
92 The proportion of coarse aggregates to fire aggregates in structural concrete is usually
[ A ] 0.50 – 1.25 [ B ] 1.25 – 4.50 [ C ] 1.50 – 2.50 [ D ] 0.25 – 0.75Answer : C
93 Fly ash when added to concrete
[ A ] Acts as aggregates [ B ] Acts as pozzolona [ C ] Improves appearance [ D ] Reduces setting timeAnswer : B
94 As per IS:456, the strength of concrete sample is less than
[ A ] The characteristic strength minus 1.35times the standard deviation [ B ] 0.80 times the characteristic strength [ C ] Greater of (a) and (b) [ D ] None of the aboveAnswer : C
95 Characteristic strength of steel has been defined as
[ A ] 0.1 % proof stress [ B ] 0.2 % proof stress [ C ] 0.4 % proof stress [ D ] Equal to proof stressAnswer : B
96 For Ordinary Portland cement concrete exposed to dry and hot weather conditions, good
moist curing period is
[ A ] 7 days [ B ] 10 days [ C ] 14 days [ D ] None of the aboveAnswer : B
97 As per IS: 456-2000, recommended value for standard deviation for concrete mix from M30
to M50 is
[ A ] 1 N/mm2 [ B ] 2 N/mm2 [ C ] 4 N/mm2 [ D ] 5 N/mm2Answer : D
98 As per 1S: 456-2000, minimum grade of concrete in seat water constructions is
[ A ] M20 [ B ] M25 [ C ] M30 [ D ] M50Answer : C
99 The section of a reinforced beam where most distant concrete fiber in compression and
tension in steel attains permissible stresses simultaneously is called
(i)Balanced section
(ii)Economic section
(iii)Critical section
[ A ] i [ B ] i and ii [ C ] i and iii [ D ] i, ii and iiiAnswer : D
100 As the percentage of steel increases
[ A ] Depth of neutral axis decreases [ B ] Depth of neutral axis increases [ C ] Lever arm increases [ D ] None of the above are correctAnswer : B
