Skip to main content

Interview questions for a civil(Structure) engineer(Concrete/Aggregate/Reinforcement (Steel bar,TMT/HYSD Bar)/Cement/ sand) A civil engineer must know.......




STRUCTURE DEPARTMENT MOST IMPORTANT INTERVIEW QUESTIONS



specification related to concrete


• Allowable free fall height of concrete = 1.5 meter
• Minimum thickness of slab = 125mm
•Tolerance limit of cube= +2mm
• Number of cubes required with respect to concrete quantity

•Grades of concrete
•Min. Concrete deposition temperature= 5°C

• Max. Concrete deposition temperature= 30°C ( in no case 40°C)



•Density of PCC(plain cement concrete) = 2400KG/cubic meter

• Density of RCC = 2500KG/cubic meter

•Concrete placing time when it has been discharged from Transit Mixer(Agitator)=30 minute

• Size of cube = 0.150 * 0.150 * 0.150 ( All dimensions are in meter)
 =150 * 150 *150 (All dimensions are in mm)

•Fly ash when used, Shall neither be less than 20% nor shall be greater than 30% of the total by mass of OPC and fly ash and shall be conform to grade - 1of IS:3812


specification related to Reinforcement ( Re- bar)


•Requirement of Binding wire per metric tonn = 8 KG

• Minimum diameter of bar used in slab
 Main bar= 8mm (HYSD bar) and 10mm (plain bar)

  #Distribution bar
minimum diameter of bar =8mm
 Max. Diameter of bar =1/8 of slab thickness 





• Minimum number of bars in square column= 4 bars

• Minimum number of bars in circular column= 6 bars

• Density of steel bar= 7850 KG/Cubic meter

• Minimum longitudinal reinforcement in column = 0.8%

•Maximum longitudinal reinforcement in column( including lap length) =6%

• Minimum diameter of Chair bar= 12mm

• Minimum diameter(Φ) of dowel bar= 12mm

• Requirement of chair bar per square meter= 1

• Grades of Re- bar
Fe-250,Fe-415,Fe-415D,Fe-415S,Fe-500,Fe-500D,Fe-500S,Fe-550,Fe-550D,Fe-600

Where (Fe-500D)
Fe- It stand for iron
500- Minimum yield strength
D-  Ductility (Not for diameter)

S- grade bars are generally used in the
 earthquake sensitive areas

•Anchorage value of Hook= 16D centimeter

•Anchorage value of 90° bend= 8D centimeter

• Lap length in compression= equal to development length but not less than 24D

• Lap length in flexture tension without hook = Development length or 30D which ever is greater

•Lap length in flexture tension with hook= Development length or 30D which ever is greater and (length of hook = 15D of 200 mm whichever is greater)

• Maximum provided slope of bar during lapping in cloumn=1:6


•For mild steel (Fe-250) bar U- type hooks are provided and for deforned bar(HYSD Bar) L- tpye hooks are provided.

• Lap splices shall not be used for bars larger  36 mm diameter except where welded

•column bars of diameter larger than 36 mm in compression can be spliced with dowels at the footing with bars of smaller size and of necessary area.

Cement

•Density of cement(of loose cement bag)= 1440 KG/ Cubic meter

• Weight of one cement bag= 50 KG

• Initial setting time = 30min.

•Final setting time = 600 min (10hours)

•Volume of cement bag=
0.03472 cubic meter = 1.2262cubic feet = 34.722=liter



• Grades of Cement

1.  33 Grade
2. 43 Grade
3. 53 Grade

Here Grade value like 33,43 & 53 indicates the Strength of cement (in Newton/ mm^2 or mega pascal(MPa)) that is achieved after 28 days of cruring.

•Type of Cement

 #
  1. Ordinary Portland Cement (OPC)
  2. Portland Pozzolana Cement (PPC)
  3. Rapid Hardening Cement(RHC)
  4. Quick setting cement(QSC)
  5. Low Heat Cement
  6. Sulphates resisting cement
  7. Blast Furnace Slag Cement
  8. High Alumina Cement
  9. White Cement(WC)
  10. Coloured cement
  11. Air Entraining Cement
  12. Expansive cement
  13. Hydrographic cement
• strength achieved by cement in Mega pascal (MPa) after proper curing in different days




Aggregate 

• Types of Aggregates
 1- Fine Aggregate (Also known as Sand)
 2- Coarse Aggregate

• Aggregate size smaller than 4.75 mm falls in the category of fine aggregate.

• Aggregate size larger than 4.75 mm falls in the category of coarse aggregate.



• Max. Allowable water absorption of aggregate = 2% (Maximum)

•Range of Specific gravity = 2.4 to 3.0

•size range of coarse aggregate = 4.75 mm 63 mm (only in concrete work)

•Size range of fine aggregate (Sand)= 150 micron to 4.75 mm

Thank you

Mukesh kumar
(www.Gyanofengineering.blogspot.com)

Comments

  1. bahut sahi jankari usefull,thanks

    ReplyDelete
  2. This is an awesome post. Really very informative and creative
    Real estate service in tiruvannamalai

    ReplyDelete
  3. thanks to share the interview question, it is useful to prepare my interview, keep more postSteel tmt bars for construction in tamilnadu

    ReplyDelete
  4. Your work is truly appreciated. The material gives lots of innovative ideas which is beneficial to our knowledge. Asphalt Paving Companies

    ReplyDelete
  5. Your blog is very valuable which you have shared here about construction. I appreciate your efforts which you have put into this article and also it is a gainful article for us. Thank you for sharing this article here. Steel Traders in India

    ReplyDelete

Post a comment

Popular posts from this blog

Granular Sub base (GSB) specifications, GSB Grading, layer thickness, Water absorption, Physical requirements (like liquid limit, Plasticity index ,AIV), construction procedure or Rolling , measurement and treatment of GSB as per MORTH 5th revision and Indian standard in Civil engineering

Granular sub-base (GSB) SUB BASE (GSB)– The full form of GSB is granular sub base.it is being laid in road work because it plays two major roles 1- it works as  drainage layer 2- it provides a good sub base to laid base layer on it. How to calculate the quantity, compaction factor value and loose thickness of GSB? To know more information kindly visit on below link 🔗  www.gyanofcivilengineering.com/granular sub-base(GSB) Quantity. Material –     The material to be used for the work shall be natural sand, crushed   gravel, crushed stone, crushed slag, or combination thereof depending upon the grading required use of material like brick metal, kankar and crushed concrete shall be permitted in the lower sub base. The material shall be free from organic or other deleterious constituents. Grading III and IV shall be used in lower sub base. Grading V and VI shall be used as sub-base-cum-drainage layer. Where the sub-base is laid in two layers as upper sub-base and lowe

Wet Mix Macadam (WMM) technical specifications as per MORTH and Indian standard in Civil engineering

WET MIX MACADAM (WMM) sub – base /base:- Wet mix macadam (WMM) act as a base course just below the bituminous layer (bitumen base course or surface course).  The thickness of a single compacted Wet mix macadam(WMM)  layer shall not be less than 75mm.when vibrating or other approved types of compacting equipment are used, the compacted depth of a single layer of the sub-base course may be up to 200mm. How to calculate the loose thickness of WMM, compaction factor and quantity of WMM ? Kindly visit on below link 🔗 https://www.gyanofcivilengineering.com/2020/05/wet-mix-macadam-wmm-quantity-compaction.html Physical requirements   Material finer than 425 micron shall have plasticity index (PI) not exceeding 6. To determine this combined portion, the flaky stone from a representative sample should first be separated out. Flakiness index is weight of flaky stone metal divided by weight of stone sample. Only the elongated particles are separated out from

Full form of various terms used in civil engineering /highway engineering or road work

Full Form of various  terms used in civil engineering  (Highway and expressway)  List of various  acronyms or abbreviations used in civil engineering  TBM- Temporary Bench mark (टे᠎म्‌प्‌ररि बेंच मार्क) BM- Bench Mark ( बेंच मार्क ) / Bituminous Macadam ( बिटुमिनस मैकडम) MSL- Mean Sea Level (मीन सी लेवल) BS- Back sight( बैक साइट) FS - Fore sight  (फोर साइट) HI - Height of Instrument ( हाइट आंफ इन्‌स्‍ट्रमन्‍ट्‌) TS-  Total Station (टोटल स्टेशन) GPS- Global Positioning System (ग्लोबल पोजिशनिंग सिस्टम) ROW- Right of Way (राइट ऑफ वे) MTV- material Transport vehicle (मटेरियल ट्रांसपोर्ट वहीकल) NGL- Natural Ground Level (नेचुरल ग्राउन्‍ड्‌ लेवल ) OGL- Original Ground level (अˈरिजन्‌ल्‌ ग्राउन्‍ड्‌ लेवल ) C&G- Clearing and Grubbing ( क्लियरिंग और ग्रबिंग) EMB- Embankment SG- Subgrade (सबग्रेड) GSB- Granular sub-base WMM- Wet Mix Macadam ( वेट मिक्स मैकडैम) WBM- Water Bound Macadam (वाटर बाउंड मैकडैम) DBM- Dense Bituminous Macadam SDBM- Semi- Dense Bitumino

WMM(Wet Mix Macadam) quantity / Compaction Factor value for WMM / Loose thickness of WMM Layer

Wet Mix Macadam (WMM) quantity / Compaction Factor value for WMM / Loose thickness of WMM Layer  In this article we shall discuss three important points about wet Mix Macadam (WMM) 1- How can we calculate the required WMM  quantity?  2 -  What is value of compaction factor for WMM? 3- How much loose thickness should be taken to get proper compacted layer thickness ?  1- How can we calculate the required WMM quantity? Let us consider Length of WMM Bed(L) = 1 Km = 1000 Met. Breadth of WMM Bed(B)= 7 Met. Thickness of WMM Layer (T)  = 150 mm =0.150 Met. Max. Dry Density (MDD) =2.230 Gram/ Cubic Centimeter = 2230KG/ Cubic metre Note -  The value of MDD is calculated by conducting proctor density test as per IS 2720 (part -28) : 1983 (Reaffirmed - May 2015). Then Volume of WMM Layer = ( Length of WMM Bed X Width of WMM Bed X Thickness of WMM Layer) Volume of WMM Layer = L X B X T  Volume of WMM Layer   = 1000 X 7 X 0.150  Volume of WMM Layer    = 1050 C

Dense Bituminous Macadam (DBM) or Bituminous Concrete (BC) layer Quantity / Compaction Factor value / Loose thickness calculation

Dense Bituminous  Macadam (DBM) or   Bituminous Concrete (BC)  quantity / Compaction Factor value for DBM or BC / Loose thickness of DBM or BC Layer  In this article we shall discuss three important points about Dense Bituminous   Macadam (DBM) or Bituminous Concrete (BC) 1- How can we calculate the required DBM/BC quantity?  2 -  What is value of compaction factor for DBM/BC? 3- How much loose thickness should be taken to get proper compacted layer thickness ?  1- How can we calculate the required DBM/BC quantity? Let us consider Length of  DBM/BC layer (L) = 1 Km = 1000 Met. Breadth of DBM/BC Layer (B)= 5 Met. Thickness of DBM/BC Layer (T)  = 50 mm =0.050 Met. Max. Dry Density (MDD) =2.441 Gram/ Cubic Centimeter = 2441KG/ Cubic metre Note  -  The value of MDD is calculated by conducting suitable test . Then Volume of DBM/BC Layer = ( Length of DBM/BC layer X Width of DBM/BC layer  X Thickness of DBM/BC Layer) Volume of DBM/BC Layer = L X B X T Volume o

DBM (Dense Bituminous Macadam) specificatins,layer thickness, physical requirements, aggregate size, grades and its measurements

 DENSE BITUMINOUS MACADAM(DBM) DBM acts as a bituminous  base course and thickness of a single compacted  layer shall be 50 mm to 100 mm.  In this article we shall discuss about Technical specifications of DBM (Dense Bituminous Macadam), layer thickness, physical requirements, aggregate size, grades and its measurements A-Scope : The work shall consist of construction in a single layer of DBM on a previously prepared base or sub-base. The thickness of a single layer shall be 50 mm to 100 mm. B - Material : The choice of binder material shall be stipulated in the contract or by the engineer, where viscosity grades of bitumen are specified, they are referred to by a designation in accordance with IS: 73. Where modified bitumen is specified, it shall conform to the requirements of IRC:SP:53 and IS:15462. Selection criteria for viscosity grade bitumen based on highest and lowest daily mean temperatures at a particular site are ]given in table no -1. 1-Coarse Agg

Difference between nominal mix and design mix of concrete

Difference between nominal mix and design mix of concrete - Concrete is most extensively used mix to achieve desired properties of structure. There are two methods to prepare the concrete mix. 1-Nominal mix 2- Design mix Nominal mix - Nominal mix specifies the fix proportion of the cement , sand and aggregates. Ingredients of concrete are mixed on the basis of volume. It is a site level mixing of ingredients to prepare concrete mix. Such type of concrete mix is generally used in small quantity or where load is not high. There are many grade of nominal mix concrete like M-5, M-7.5, M-10, M-15 and M-20. In above grades of concrete mix  the letter 'M' refers to Mix where as the value like 5,7.5,10,15 etc indicates the compressive characteristic strength of concrete after 28 days in specified conditios. Unit of this compressive characteristic strength of concrete is  Newton /mm 2. The ratio of various grade of concrete is being given below - M-5 

Bituminous Concrete (BC) specifications viz. Layer thickness, Mix and material requirements, grading , laying trials, Rolling , Construction procedure, transport and joint specifications, surface finish and quality control,measurement and rate etc..as per MORTH and Indian Standard

Bituminous concrete(BC)- Bituminous concrete( BC) is used for wearing  course and profile corrective courses.BC is generally laid in single layer on a previously prepared bituminous bound  surface. The thickness of single layer of BC shall be 30mm,40mm and 50mm. 1 -MATERIAL A- Bitumen - The bitumen shall be viscosity graded paving bitumin complying with IS 73 or specified in contract aggrement. The type and grade of bitumen to be used would depend upon the climatic condition and the traffic. Selection criteria of viscosity graded (VG) paving bitumens based on climatic conditions B- Coarse Aggregate It consist of crushed rock,crushed gravel or other hard material retained on 2.36 mm sieve. It shall be clean ,hard,durable and of cubical shape,free from dust,and  soft organic and other deleterious substances. The aggregates  shall satisfy the physical requirements of table  no. -2 (Table no. 500-16 ,as per MORTH 5th revision) where crushed gravel is proposed 

Civil engineering interview questions in Roadway/Highway /Expressway department

  Welcome friends, We shall learn about the various questions which are frequently ask by an  interviewer In the field of infrastructure.  So let's get start....... EMBANKMENT/SUBGRADE/BORROW AREA •Liquid Limit  <50% •Plastic Limit  < 25% •Proctor Density(Min. Value) For Embankment =1.52 to 1.60 gram/cubic centimeter For Subgrade= 1.75 gram/ cubic centimeter Sub-grade top • Field Dry Density (FDD) For Embankment= min. 95% For Sub grade = min. 97% •Number of test For Embankment = 1set/3000 sq.meter(1set=10pits) For subgrade= 1set/2000 sq.meter (1 set=10 pits) GRANULAR SUB- BASE •Maximum thickness of single compacted layer = 200 mm • Minimum thickness of single compacted layer( only when GSB is laying in two layers) = 150 mm •Max. Allowable size of aggregate =75mm •Number of grading of GSB = 6 •Liquid limit  should not be  more than 25% ( test procedure as per IS 2720 (part 5)). •Plasticity index should  not be more than 6%

Process of laying of DBM/ BC( weather limitations, Rolling of laid material and cleaning of bed)

First of all i want to tell you that DBM act as bituminous base course while BC acts as wearing course. LAYING OF DBM(Dense Bituminous macadam) /BC(Bituminous concrete)  Laying of DBM/BC is done with the help of paver. There are following points which clearly indicates detailed process of laying. To know more about the bituminous concrete (BC) ,please click on below link......... https://gyanofcivilengineering.com/2020/05/bituminous-concrete-bc-specifications.html 1-Weather and seasonal limitations- Laying shall be suspended: A- In presence of standing water on the surface B-When rain is imminent, and during rain, fog, or dust storm C-When the base/binder course is damp D-When the air temperature on the surface on which it is to be laid is less than 10°C for mixes with conventional bitumen and is less than 15°C for mixes with modified bitumen E- When the wind speed at any temperature exceed the 40 km per hour at 2 m height. 2-Cleaning of surface- The