L&T civil Engineer Interview Question |Top 102 fresher question
QUE 1 – How will trucks be checked on-site when receiving concrete?
ANS 1 – A. Revolution Counter
B. Ticket Checked for Concrete Batching time and Slump Value at the plant.
C.Slump Test.
D. Temperature Test (32 C maximum @ Site).
E. Assure Lab Technician is present at the site and performs testing.
F. 6 Cubes or 4 Cylinders should be taken per 50cum or recommended in the project specification.
QUE 2 – What is the purpose of the slump test?
ANS 2 – To determine the consistency of the workability of the concrete mix and to check for the required slumps.
QUE 3 – What are allowable slumps?
ANS 3 – 2.5cm to 7.5cm (for vibrated structure and without admixture) and If with admixture and plasticizer, Slump depends upon the design mix. Slump shall be checked as per design mix.
QUE 4 – What is a plasticizer?
ANS 4 – Usually applied at a low water-cement ratio concrete to make it workable.
QUE 5 – What is the maximum temperature of concrete that can be poured into a concrete structure?
ANS 5 – 32 Degrees C.
QUE 6 – Min and Max atmospheric (ambient) temperature prior to paving?
ANS 6 – Min is 5 Degree C in cold weather and 45 degrees C max for hot weather.
QUE 7 – Min and Maximum temperature of concrete at the site prior to pouring?
ANS 7 – Min Concrete temp is 10 degrees, and Max is 32 degrees C.
QUE 8 – What is the purpose of curing?
ANS 8 – 1. To maintain the amount of water in the concrete mix.
2.To minimize hairline cracks
QUE 9 – Types of Curing?
ANS 9 – Water Curing – as in ponding, spraying, wet sand and wet earth Membrane Curing -asin plastic film, liquid membrane curing compound, and reinforced paper Steam Curing.
QUE 10 – When will you apply the curing of the concrete?
ANS 10 – After the concrete has initially set (35 to 40 minutes is the initial setting time of concrete)
QUE 11 – For how many days are you going to cure a structure?
ANS 11 – Seven days (in some cases like PPC types of cement, 14 days of curing are recommended).
QUE 12 – What is hydration?
ANS 12 – It is the formation of a compound by the combination of water and other substances orin concrete; itis the chemical reaction between water and cement.
QUE 13 – How many times do you apply the curing membrane?
ANS 13 – At least two times. The second application is perpendicular to the first and applied after the first application has set.
QUE 14 – Concrete Curing Water shall not have more than …………….. Of total dissolved solids (TDS).
ANS 14 – 1000 ppm
QUE 15 – Concrete can be dropped freefall at height of…………
ANS 15 – 1.5 meter
QUE 16 – Max and min slope of chutes used in pouring concrete?
ANS 16 – Max slope is 1:2 (Vertical to Horizontal), Min slope is 1:3
QUE 17 – Advantages of reducing the water-cement ratio of concrete mix?
ANS 17 – Increased strength, Increase water tightness, Lower absorption, increased resistance to weathering, a better bond between concrete and reinforcement.
QUE 18 – What are the two basic types of concrete?
ANS 18- Structural and nonstructural concrete.
QUE 19 – How would you compare 7 days and 28 days compressive strength of concrete?
ANS 19- 70 to 75 % of that of 28 days strength.
QUE 20 – What is a composite structure?
ANS 20 -It is a structure composed of two materials as in steel and concrete.
QUE 21 – What is a non-composite structure?
ANS 21 – Itis a structure made of either concrete or steel.
QUE 22 – What are the reasons behind the cracks?
ANS 22 – Poor Curing Practice, Poor design, Poor Vibration which results in segregation, less rebar covering, poor quality of concrete, movement of false work or forms, higher water-cement ratio, Severe atmospheric attack which shows the effect on the heat of hydration with water initially
QUE 23 – What are the concrete samples?
ANS 23 – The cylinder and the cubes for the compressive strength test.
QUE 24 – Within how many hours should concrete mix be discharged after leaving the batching plant or after all the aggregates, cement, and water are in the mixer?
ANS 24 – Within one hour if the mixer is an agitated mixer (Also depends on the design mix) and Within30 minutes if the mixer is a non-agitated mixer.
QUE 25 – What is the initial setting time of Concrete Mix?
ANS 25 – 35 to 40 minutes.
QUE 26 – What is the mixing time of a stationary or central batching plant (concrete)?
ANS 26 – 50 to 90 seconds
QUE 27 – What is the agitating speed of the mixer?
ANS 27 – 2 to 6 revolutions per minute (rpm)
QUE 28 – What is the mixing speed of the mixer?
ANS 28 – 6 to 18 rpm.
QUE 29 – What is concrete fatigue?
ANS 29 – It is the weakening of a material caused by repeated loads.
QUE 30 – What is creep?
ANS 30 – It is deformation due to the sustained load.
QUE 31 – How would you know if the concrete has gained its initial set?
ANS 31 – If there is no more water seen (brightness) on the surface of the concrete, or if there is no water on the surface of the concrete.
QUE 32 – If agitated concrete is discharged after more than one hour, what will happen?
ANS 32 – The concrete is over mixed, becomes hot, and the strength is reduced
QUE 33 – How many layers are in the concrete cube?
ANS 33 – Concrete Cube is cast in 3 layers.
QUE 34 – How many strokes are done in one layer in a concrete cube?
ANS 34 – 35 Strokes in one layer.
QUE 35 – What is the size of rode usedin concrete cube casting and slump test?
ANS 35 – Dia – 16mm and 600mm length.
QUE 36 – What is the size of a concrete cube?
ANS 36 – 150mm X 150mm X 150mm.
QUE 37 – What is the size of slump cones?
ANS 37 – Height – 30cm, Top of Cone – 10cm, and Bottom of cone – 20cm.
QUE 38 – How many layers are in the slump test??
ANS 38 – 3 Layers in ASTM and BS but 4 Layers in Indian standard
QUE 39 – How many strokes are done in one layer in a slump test?
ANS 39 – 25 Strokes
QUE 40 – What are the essential elements of Concrete placement?
ANS 40 – A. The maximum height of the concrete drop is less than or equal to 1.5 meters.
B. Segregation must be prevented by ensuring transit mixture is approved, has operating revolution counter, no adding water after batching, and concrete is placed in such a manner to prevent segregation (only shovels can be used to move concrete around inside the forms no raking allowed. Vibrators should not be used for that purpose.
C. Proper vibration must be implemented (proper vibrating – dropping the vibrator under its own weight until it gets to the desired drop height, then leaving it there for 3-7 seconds then pulling at the count of 3 to 4 seconds. When vibrating subsequent layers, the vibrator must penetrate a centimeter into the older layer.
D. Some laborers must be continuously watching the forms in case a wall is being poured, proper height of each concrete lift must be observed, such as the usual 600mm stated normally in project specifications. Also, tamping on the wall is necessary to assist in the consolidation process.
E. The concrete temperature and the slumps are two strong indicators of the inspector’s knowledge. A slump between 75mm and 125mm is normal for normal
pours. The maximum allowed temperature for concrete when arriving at the project site is 32.
41. How do you measure the volume of concrete?
The volume of concrete is calculated by Multiplying its Length, Width, and Thickness together. For
Example – 1m x1m x1m = 1 m³ of volume of concrete.
42. Why Concrete Cover is provided for reinforcement?
Concrete cover for reinforcement is required to protect the rebar against corrosion and to provide resistance against fire.
43. How to do check level on construction site?
I will check the level on the construction site by Spirit level, Dumpy Level, and Leveling Pipe.
44. What is the accuracy of the dumpy level or minimum reading we can take?
With the help of a dumpy level, we can take up a 5 mm accurate reading or minimum reading.
45. How do you calculate the weight of 12m long and 10mm dia. Steel on-site?
It’s simple,
By multiplying the length of the steel bar with its unit weight
(Unit wt. of 10mm = 0.60 kg/m)
Weight of steel = 0.60x 12
= 7.2 kg
46. Which is the equation used for calculating the unit weight of the steel bar?
(D²/162) is an equation used for calculating the unit weight of the steel bar
47. What is the size of a concrete cube?
The standard size of a concrete cube is 15 cm x 15 cm x 15 cm
48. What do you do if any concrete cube fails in 28 days compressive strength test?
If the concrete cube fails in the strength test, I will conduct a core cutter test on concrete and
send a report to higher authorities.
49. What is the mix ratio for M – 20 Grade of concrete?
For M20, the Mix ratio is 1: 1.5: 3
50. What are the steps involved in Building Construction?
There are different steps involved in Building construction like,
Concreting
Masonry work
Plastering work
Flooring work
Formwork
Steel cutting and Bending
Plumbing Work
Electrical Work
51. What is the Unit weight of 12 mm Steel Bars?
0.89 kg/m
52. What is the Density of Steel?
7850 kg/m³
53. In Fe– 415 Steel Grade, 415 indicates the___________of Steel.
Tensile Strength
54. What is the Volume of a 50 kg bag of cement?
0.035 m³
55. in Residential Building, Average Value of Stair Width?
900 mm
56. The Slope of Stair should not exceed.
40º
57. Minimum diameter of steel in Column.
12 mm
58. Standard Size of Brick?
19 cm x 9 cm x 9 cm
59. What is Unit Weight of RCC?
2500 kg/ m³
60. One Acre = ____________Sq. ft.
43560 Sq. ft.
61. What is the Full Form of UTM?
Universal Testing Machine
62. Cement Expire After?
3 month
63. One square meter = _________ Sq. ft.?
10.76 Sq. ft.
64. What is unit weight of 25 mm Steel Bars?
3.85 kg/m
65. One Hectare = _______Acres
2.47 Acres
66. One Gallon = ________Liters
3.78 Liters
67. One kilo newton is equal to _________ kilograms
101.97 KG
68. One Ton is equal to _________ kilograms
1000 KG
69. Maximum Free fall of concrete allowed is______?
1.5 m
70. Instrument used for level work on a construction site?
Dumpy Level
71. Minimum Bars in Circular Column Should be_______
6 Nos.
72. What is the Full Form of AAC?
Autoclaved Aerated Concrete
73. What is the Full Form of NDT?
Non – Destructive Test
74. What is the Full Form of JCB?
Joseph Cyril Bam ford
75. Which Test is conducted to determine the bearing capacity of Soil?
Plate Load Test
76. Ring and ball test are conducted on which construction material?
Bitumen
77. Minimum hook length as per IS Code?
Ans: 75 mm
78. What is the extra length in Bent up bars?
0.45
79. What is the Least Count of Dumpy?
5mm
80. What is Full of EGL?
Existing ground level.
81. A First Class Brick Should Absorb Water More than?
20 %
82. Number of Bricks used in 1 Cubic meter of Brickwork?
500 Nos.
83. The Normal Consistency of Portland cement?
25 %
84. The Expansion in Portland cement is tested by…
Soundness Test
85. According to IS Code, Full Strength of Concrete is achieved after?
28 Days
86. What is the Volume of 1 bag of cement?
0.035 m³
87. Minimum Grade of Concrete Used For RCC?
M – 20
88. Cement Expire After?
3 month
89. What is the Full Form of DPR?
Detailed Project Report
90. What is the initial and final setting time for cement?
Initial: Less than 30 min and 600 min.
91. What are the Responsibilities of a Construction Manager in the project?
Responsibilities of a Construction Manager in the project.
Supervising the construction Site.
Estimate the proper cost of the project
Purchasing the materials required for construction before work begins.
Purchasing the materials required for construction before work begins.
Analyzing the proposals.
Construction Scheduling & Monitoring
92. What can be the potential risk factors for workers on the construction site?
Following are the risk factors for workers, for not following the safety protocols:
Risk to fall from height
Failure Scaffold and Trench
Change of Electric shock and arc blast
Motion injuries
93. What you know about Hybrid Foundation
Hybrid Foundation is used to reduce the amount of settlement in high rise building, which contains
both soils supported mat and piles.
94. What are the different ways of demolition?
Demolition is commonly done through Hydro-demolition, Dismantling and Pressure Bursting.
95. Explain Floating Slab Foundation?
Type of mat foundation having the hollow mat formed by the grid of thick reinforced concrete
walls between two thick reinforced concrete slabs is termed as Floating Slab Foundation.
96. Explain what is flashing?
Joints in a building can be sealed and protected from water penetration through extended
construction called as Flashing. It can be installed at the walls and parapets.
97. State different types of roof systems?
Following are the types of roof system,
Slate or Stone roofs
Wood shingle roofs
Metal roofing systems
98. What can be the phase inspections done by local authority while construction?
Various inspections during the construction includes,
Inspection of Site
First or pre-construction Inspection
Inspection of Foundation before placing of concrete
Framing inspection
Insulation inspection is done after insulation
Lastly, the final inspection is done after the completion of the construction
99. State out some of the Inspections, done after the completion of construction?
Listed are some of the checking or inspection is done on the exterior side of the construction is,
Storm sewer system
Safety provision (terraces, porches, areaways)
Accessory buildings
Drainage
Retaining Wall
Compaction of fill material
Caulking at opening
Pavement edging
Protection against moisture penetration
Design of dwelling structure
100. Alternate Bid is______?
An alternate bid is a proportion stated in the bid to be subtracted or summed from the base bid
amount. Alternate materials or methods of construction force Alternate bids are to be proposed.
101. Explain the Order of Change request?
Change order request is a written document given by the owner, requesting an adjustment to the
contract sum or an extension of the contract time. It can be issued by the architect or owners
representative
102. Explain the term is Demising Wall?
Demising wall act as a boundary that separates your land or house from neighbor’s house or
property.
The Significance of the labor and material payment bond is if the contractor fails to pay for all labor,
materials, equipment’s or services in accordance with the contract, he or she will guarantee
payment to the owner under this bond. Hence itis a bond between the owner and the main
contractor.