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Civil engineering interview Questions and their answers(in English and Hindi) in pdf




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Civil engineering interview questions and their answers in PDF file

Question 1-  What do you mean by Fe 500D re-bar?

Answer -

Various grades of Re-bars are used in civil engineering works I. e. Construction of structures, buildings etc. 

Some text is written on re-bars(Fe 500D) that provides following information. 

Where (Fe-500D)

Fe- It stand for iron

500- Minimum yield strength

D-  Ductility (Not for diameter)

Question 2- What is DBM? 

 प्रश्न 2- डीबीएम क्या है?

Answer-DBM - The full form of DBM is Dense Bituminous macadam.

DBM is mixture of sand(fine aggregate) , coarse aggregate,filler and bitumen in suitable proportions.

DBM - DBM का पूर्ण रूप Dense Bituminous Macadam है।

 डीबीएम उपयुक्त अनुपात में रेत(sand), coarse aggregate , भराव (filler)  और कोलतार(Bitumen) का मिश्रण है।

 

To know more about DBM,kindly click on below 🔗 

www.gyanofcivilengineering.com/Dense bituminous macadam(DBM)

Question 3 -Why dowel bars are used in PQC roads?

प्रश्न 3-PQC सड़कों में Dowel bar का उपयोग क्यों किया जाता है?

Answer- Dowel bars are used in pavement quality concrete (PQC)  because these bars(Dowel Bars) transfer load from one slab to another. Dowel bars also allow the horizontal slab movement (Expansion and contraction) which takes place due to Change in temperature and also helps to maintain slab alignment.

 उत्तर- डॉवेल बार का उपयोग PQC में किया जाता है क्योंकि ये बार (Dowel bars ) एक स्लैब से दूसरे स्लैब में  लोड ट्रांसफर करते हैं।  डॉवेल बार क्षैतिज स्लैब movement (विस्तार और संकुचन) को भी अनुमति देता है जो तापमान में परिवर्तन के कारण होता है और स्लैब संरेखण (alignment) को बनाए रखने में भी मदद करता है।

Question 4 - What is the Difference between WMM(Wet mix macadam) and WBM(Water bound macadam)? 

प्रश्न 4 - WMM (वेट मिक्स मैकडैम) और WBM (वाटर बाउंड मैकडैम) में क्या अंतर है?

Answer- 

1- WBM stand for Water Bound Macadam. WBM consist of clean crushed aggregates with screening, binding material (Filler) where required. 

While WMM stands for Wet Mix macadam. WMM consist of clean, Crushed ,graded aggregate and granular material.

 जवाब- 

1- WBM का पूर्ण रूप वॉटर बाउंड मैकडैम (water bound macadam) होता है।  WBM में स्क्रीनिंग, बाइंडिंग मटीरियल (फिलर) के साथ साफ कुचले हुए एग्रीगेट(crushed aggregate) शामिल होते हैं, जहां आवश्यकता होती है।

 जबकि WMM का मतलब वेट मिक्स मैकडैम (wet mix macadam) होता है।  WMM में साफ, कुचला(crushed) , ग्रेडेड एग्रीगेट और ग्रेन्युलर मटेरियल होता है।

2- Water is postmixed in WBM while in WMM, water is premixed.

 2- WMM मे पानी पहले मिलाया जाता है जबकि WBM मे पानी बाद मे मिलाया जाता है  

3 -The maximum aggregate size used in WBM mix is 75 mm while in WMM, Maximum Aggregate size is 53 mm. 

3-WBM मिश्रण में उपयोग किए जाने वाले अधिकतम aggregate का आकार 75 मिमी है जबकि WMM में, अधिकतम aggregate का आकार 53 मिमी है।

4 - After final compaction of WBM, The pavement shall be allowed to dry overnight and in next morning, Hungry spots shall be filled with screening and binder material  I.e aggregate, screening and binder material layers are laid one after another.

While in WMM, aggregate and granular materials are pre- mixed in bins of batching Plant. 

 4 - डब्ल्यूबीएम के अंतिम संघनन के बाद, फुटपाथ को रात भर सूखने दिया जाएगा और अगली सुबह, भूखे स्थानों को स्क्रीनिंग और बांधने की सामग्री से भरा जाएगा। कुल मिलाकर, स्क्रीनिंग और बाइंडर सामग्री की परतें एक के बाद एक रखी गई हैं।

 WMM में, कुल और दानेदार सामग्री बैचिंग प्लांट के डिब्बे में पूर्व मिश्रित होती है।

5- Quantity of water used is less in WMM as compared to WBM. 

 5- WBM की तुलना में WMM में उपयोग किए गए पानी की मात्रा कम  होती है।

6 - WBM coarses take more time in construction as compared to WMM. 

6 - WBM के निर्माण में  WMM की तुलना में लगता अधिक समय है।

To get the more information about wet mix macadam (WMM), please click on below 🔗 

www.gyanofcivilengineering.com/wet-mix-macadam(WMM)



Question 5 - What is the Difference between Prime coat and Tack coat ? 

प्रश्न 5 - प्राइम कोट (Prime coat) और टैक कोट (tack coat) में क्या अंतर है?

Answer- 

1 - Prime coat is applied on base course(At WMM course or WBM coarse) While tack coat is applied on surface treated with prime coat, bituminous base course (on the surface of DBM before laying Bituminous Concrete) and Concrete surface(Before laying bituminous layer over concrete surface).

 1 - प्राइम कोट, बेस कोर्स (WMM and WBM coarse पर) पर डाला जाता है जबकि tack coat , Prime coat , बिटुमिनस बेस कोर्स (बिटुमिनस कंक्रीट बिछाने से पहले डीबीएम की सतह पर) और कंक्रीट की सतह (ठोस सतह पर परत बिटुमिन बिछाने से पहले)  पर लगाया जाता है|

2 - Material used in Prime coat is cationic bitumen emulsion (SS-1) or medium curing cutback bitumen while material used in tack coat is cationic bitumen emulsion (RS-1), Low viscosity paving bitumen of VG 10 grade and for sites at sub- zero temperatures ,cutback bitumen RC:70 is used to apply tack coat.

2 - प्राइम कोट में उपयोग की जाने वाली सामग्री cationic कोलतार इमल्शन (SS-1) या medium curing cutback कोलतार है, जबकि tack कोट में उपयोग की जाने वाली सामग्री cationic कोलतार इमल्शन (RS-1) है, VG 10 ग्रेड की low viscosity बिटुमेन और साइट्स के लिए sub zero तापमान पर -, कटबैक बिटुमेन RC: 70 का उपयोग tack कोट लगाने के लिए किया जाता है।

3 - Tack coat is less dense than prime coat .

 3 - टैक कोट प्राइम कोट की तुलना में कम घना होता है।

Question 6- What is the Minimum and maximum Single compacted layer thickness of subgrade,  GSB Layer, WMM Layer, DBM layer and BC layer ? 
प्रश्न 6- sub grade, GSB लेयर, WMM लेयर, DBM लेयर और BC लेयर की न्यूनतम और अधिकतम सिंगल कॉम्पैक्ट लेयर मोटाई क्या है?

Answer- 
1 - sub grade 
a) Minimum single compacted layer thickness - 
Not specified (But 75 mm can be considered as minimum single compacted soil layer thickness with 50 mm maximum size of coarse material)

(b) Maximun single compacted layer thickness- 250 mm

2 - GSB layer
(a) Minimum single compacted layer thickness - 150 mm (But sometime it was seen that GSB Layer is laid of 100 mm thickness)

(b) Maximun single compacted layer thickness- 200 mm

3- WMM layer
(a) Minimum single compacted layer thickness - 75 mm
(b) Maximun single compacted layer thickness- 200 mm

4 - DBM layer
(a) Minimum single compacted layer thickness - 50 mm
(b) Maximun single compacted layer thickness- 100 mm

5 - BC layer
(a) Minimum single compacted layer thickness - 30 mm
(b) Maximun single compacted layer thickness - 50 mm

उत्तर-
 1 - सब- ग्रेड
 a ) न्यूनतम एकल संकुचित परत की मोटाई -
 निर्दिष्ट नहीं (लेकिन 75 मिमी को मोटे एकल मिट्टी की परत की मोटाई माना जा सकता है जिसमें 50 मिमी मोटे आकार के coarse aggregate होते हैं)
 (b) अधिकतम एकल कॉम्पैक्ट लेयर की मोटाई- 250 मिमी

 2 - जीएसबी परत
 (a) न्यूनतम एकल कॉम्पैक्ट परत की मोटाई - 150 मिमी (लेकिन कभी-कभी यह देखा गया था कि जीएसबी परत 100 मिमी मोटाई से बना है)
 (b) अधिकतम  एकल कॉम्पैक्ट लेयर की मोटाई- 200 मिमी

 3- WMM परत
 (a) न्यूनतम एकल कॉम्पैक्ट परत की मोटाई - 75 मिमी
 (b) अधिकतम एकल कॉम्पैक्ट लेयर की मोटाई- 200 मिमी

 4 - DBM परत
 (a) न्यूनतम एकल कॉम्पैक्ट परत की मोटाई - 50 मिमी
 (b) अधिकतम एकल कॉम्पैक्ट लेयर की मोटाई- 100 मिमी

 5 - BC परत
 (a) न्यूनतम एकल कॉम्पैक्ट परत की मोटाई - 30 मिमी
 (b) अधिकतम एकल कॉम्पैक्ट परत की मोटाई - 50 मिमी

Question 7 - Why tie bars are used in pavement quality concrete (PQC) pavement?

फुटपाथ गुणवत्ता कंक्रीट (PQC) फुटपाथ में टाई बार का उपयोग क्यों किया जाता है?

Answer -
Tie bars are generally used at longitudinal joints and edge joint. These bars are generally high yield strength deformation (HYSD) bars. 

Tie bars are used to maintain the faces of rigid pavement slab in position and these bars also transfer the some amount of load but these bars can not be used as main bars for load transfer from one slab to another.

टाई बार का उपयोग आम तौर पर अनुदैर्ध्य जोड़ों और किनारे के जोड़ पर किया जाता है।  ये bars आम तौर पर  high yield strength deformation (HYSD) bars होते हैं।

 टाई bars का उपयोग कठोर फुटपाथ स्लैब के faces को स्थिति बनाए रखने के लिए किया जाता है और ये bars लोड की कुछ राशि को भी हस्तांतरित(transfer) करती हैं लेकिन इन bars को मुख्य bars के रूप मे एक स्लैब से दूसरे स्लैब पर लोड को हस्तांतरित करने लिए के लिये इस्तेमाल नहीं किया जा सकता है।

Question 8 - Why do you Mean by nominal size of aggregate?

Aggregates के nominal (नाममात्र ) आकार से आप क्या समझते हैं?

Answer -
Nominal size of aggregates refers to the that Sieve size (sieve opening) through which 90 -100% of aggregates passes from that sieve size. It means 90 -100% aggregates are smaller than nominal size. 

Aggregates का nominal आकार उस छलनी आकार (चलनी खोलना) को संदर्भित करता है जिसके माध्यम से 90 -100% aggregates उस छलनी के आकार से गुजरते हैं।  इसका मतलब है कि 90 -100% aggregates nominal आकार से छोटे होते हैं।

For example - if nominal size for any composition is 19 mm it means 90 -100% aggregates of that composition are small than 19 mm or 90 -100% aggregates will pass through 19 mm sieve opening.

यदि किसी रचना(composition) के लिए nominal आकार 19 मिमी है तो इसका मतलब है कि उस रचना के 90 -100% aggregates 19 मिमी से छोटे हैं या 90 -100% aggregates 19 मिमी की छलनी की openings से गुजरेगे।


Question 9 - What do you know about the Reinforced soil earth wall (RS wall / RE Wall) ?

Answer -
• Minimum thickness of RS/RE wall panels is 180 mm. (including facia textures, logos and embellishments)
•Minimum Concrete grade of RS/RE panels is M 35.
• Minimum width of geotextile strip to cover gaps between panels is 100 mm. 
•Height of point of impact at crash barriers above top of pavement is 800 mm. 
•Maximum spacing of reinforcing elements shall not exceed 800 mm for RS/RE wall using panels and blocks. 
•Minimum thickness of strip footing ( levelling pad PCC) is 150 mm. 
•Minimum width of strip footing ( levelling pad PCC) is 350 mm. 
•Minimum concrete grade for levelling pad PCC( strip footing) is M 15.
•Minimum depth of embedment below finished ground level at the foot of wall is 1000 mm. 
•Maximum compacted soil thickness of each layer is 200 mm. 
•Various types of reinforcements used in RS/RE wall
1 - Metallic elements like bars, strips, plates etc. 
2 - Metallic reinforcement in form of mesh
3 - Polymeric elements like strips, grids, rods mesh etc. 
•Minimum length of reinforcement shall be 0.7 H to 3 met. Whichever is greater.
Where H is design height (depth of embedment plus height above ground level) of the RS/RE wall. 

To know more ........click on below 🔗 


Question 10 - When will the berm provide in RE/RS wall? And what shall be the minimum width of such berm? 

RE /RS दीवार में बर्म (berm) कब प्रदान करेगा?  और इस तरह के बरम की न्यूनतम चौड़ाई क्या होगी?

Answer -
Where the height of reinforced soil earth wall exceeds 10 m, the designer may consider providing a berm. And the minimum width of such berm shall be 1.5 m. 

उत्तर -
 जहां प्रबलित मिट्टी पृथ्वी की दीवार(RE/RS wall)  की ऊंचाई 10 मीटर से अधिक हो, तब डिजाइनर एक बर्म प्रदान करने पर विचार कर सकते हैं।  और ऐसे  बर्म (berm) की न्यूनतम चौड़ाई 1.5 मीटर होगी।

Question 11 - What is the difference between MDD and FDD? 

MDD और FDD में क्या अंतर है?

Answer -
MDD - MDD refers to Maximum Dry Density. 
MDD for subgrade,sub base and base course refers to the maximum compaction of layer particles at optimum moisture content(OMC)  by conducting proctor test. and MDD for surface course is also calculated by conducting proctor test. 
MDD is calculated in Laboratory.

FDD - FDD refers to field dry density. 
FDD for subgrade, sub-base course ,base course and surface course means the compaction of layer particles achieved at construction site with the help of Roller or any other compaction equipment.
FDD is always calculated as a percentage measure with respect to MDD. 

उत्तर -
 MDD - MDD अधिकतम शुष्क घनत्व को संदर्भित करता है।
 सबग्रेड, सब बेस और बेस कोर्स के लिए एमडीडी प्रॉक्टर टेस्ट आयोजित करके इष्टतम नमी सामग्री (OMC) में परत कणों के अधिकतम संघनन को संदर्भित करता है।  प्रॉक्टर टेस्ट आयोजित करके सतह  के लिए एमडीडी की भी गणना की जाती है |MDD की गणना प्रयोगशाला में की जाती है।

 FDD - FDD शुष्क घनत्व क्षेत्र को संदर्भित करता है।
 Sub grade , सब-बेस कोर्स, बेस कोर्स और सरफेस कोर्स के लिए एफडीडी का मतलब है कि रोलर या किसी अन्य कंपटीशन उपकरण की मदद से निर्माण स्थल पर प्राप्त परत के कणों का संघनन।
 एफडीडी की गणना हमेशा एमडीडी के संबंध में प्रतिशत माप के रूप में की जाती है।

Question 12 - What is the minimum width of geotextile strip to cover gaps between panels in the construction of Reinforced soil earth wall ?

 प्रबलित मिट्टी पृथ्वी की दीवार के निर्माण में पैनल के बीच अंतराल को कवर करने के लिए भू टेक्सटाइल पट्टी की न्यूनतम चौड़ाई क्या है?

Answer -
The Minimum width of geotextile strip to cover gaps between panels is 100 mm. 

उत्तर -
 पैनल के बीच अंतराल को कवर करने के लिए भू टेक्सटाइल पट्टी की न्यूनतम चौड़ाई 100 मिमी है।

Question 13 - What is the difference between Retaining wall and Reinforced soil earth wall(RE/RS) Wall? 

Answer -
 Retaining wall - Retaining wall is a rigid structure. These are constructed to bear the lateral pressure of backfill material or soil. 
A huge quantity of reinforcement is used in construction of various parts of Retaining wall like raft(including both Heel portion and toe portion)  and stem. 
Whole lateral pressure is counteracted by stem and raft. 

Reinforced soil earth wall - RS/RE Wall (Reinforced soil earth wall) is a self stabilized and rigid structure that is designed or used to restrain the soil deformation and achieve the desired soil slope.
The stability of RS/RE wall is maintained by its own weight.
The friction between reinforcement (metallic elements or polymeric elements) and soil keeps the structure in its position. Due to this friction force ,less lateral force exerts on precast panel members of RS/RE wall. 

Question 14 - why CBR test is conducted in construction of Highways?  

Answer - CBR stands for California Bearing Ratio. CBR test is conducted to calculate the  strength or bearing capacity of soil. The thickness of pavements and  thickness of layers in road construction are calculated on the the basis of CBR value and curve. 

Question 15 -What is Rolling  and why rolling is required in road construction? 

Answer - Rolling is an artificial process to achieve compaction by pressing the particles close to each other in any required road layers.

Air during Rolling is expelled from the void space in the soil mass and, therefore, the mass density is increased.
Rolling of a soil mass is done to improve its engineering properties.

रोलिंग किसी भी आवश्यक सड़क परतों में कणों को एक दूसरे के करीब दबाकर संघनन प्राप्त करने की एक कृत्रिम प्रक्रिया है

 रोलिंग के दौरान हवा को मिट्टी के द्रव्यमान(soil mass) में शून्य स्थान(void space) से निष्कासित(expelled) कर दिया जाता है और इसलिए, जन ​​घनत्व (mass density) में वृद्धि होती है।
 मिट्टी के द्रव्यमान (soil mass) का रोलिंग इसके इंजीनियरिंग गुणों को बेहतर बनाने के लिए किया जाता है।

To get more information about rolling patterns and number of required passes, kindly click on below link 


Question 16 -What is the maximum depth of soil excavation from borrow area? 

Answer - The maximum depth of soil excavation from borrow area is 1.5 met. 


Question 17 How much % of compaction(FDD) is required for the embankment layer In the construction of road? And What will be the FDD (compaction ) value of embankment layer for more and equal to  6 met. embankment filling  in the Construction of road? 

Answer -Minimum value of FDD for embankment layer is considered as 95 % of MDD. While Minimum value of FDD for embankment layer having  filling height more  or equal to 6 met. should be 97% of MDD.

Question 18 -What is the initial settling time and final settling time of cement? 

Answer - 
(a) Initial setting time: Not less than 30 minutes 
(b) Final setting time: Not more than 600 minutes 

Question 19 -Why is white colour used  instead of yellow colour in road marking on the Concrete surfaces ? 

कंक्रीट सतहों पर सड़क के अंकन में पीले रंग के बजाय सफेद रंग का उपयोग क्यों किया जाता है?


Answer - Under natural light, the white light reflects the light of most wave-length whereas other colours absorb different wave length of light energy. The yellow colour may offer slightly better contrast with concrete surface compared to white colour. But the reflectivity of white is better as compared to yellow. Moreover, the importance of reflectivity is more during night time and wet conditions. 

 In view of better retro reflectivity and to have uniformity, it has been decided that white colour markings shall be used on concrete surface instead of yellow markings as per IRC:35- 2015.

Question 20 -what do you mean by Bypass, new alignment and realignment of highway? 

प्रश्न 20-  हाई-वे के बाईपास, नए एलाइनमेंट और रीएलाइनमेंट से आपका क्या अभिप्राय है?

Answer

1-Bypass road- A new constructed highway to pass the traffic from outer of any city or town is know as bypass road. The Bypasses are constructed to bypass the traffic from outer of city to minimize traffic flow. 

1-By pass road - किसी भी शहर या कस्बे के बाहरी हिस्से से ट्रैफिक को पास करने के लिए एक नया निर्मित हाईवे बाईपास रोड के रूप में जाना जाता है।  यातायात के प्रवाह को कम करने के लिए बाइपास का निर्माण शहर के बाहरी इलाकों से यातायात को निकालने  के लिए किया जाता है।

2- New alignment - when a road is constructed at the location where there was no road exist before it. Such type of road alignment is known as new alignment. 

2- New alignment - जब किसी सड़क का निर्माण उस स्थान पर किया जाता है जहाँ पहले कोई सड़क मौजूद नहीं थी।  इस तरह के सड़क संरेखण को नए संरेखण के रूप में जाना जाता है।

3-Realignment - when a road is constructed by changing its center line (C. L.) at the same location where there was road exist before it.Such type of road alignment is known as Re-alignment of road. And when realignment takes place in whole road project,that project is known as realignment project. 

3-Realignment - जब किसी सड़क को उसकी केंद्र रेखा (C. L.) से बदलकर उसी स्थान नयी केंद्र रेखा पर बनाया जाता है, जहाँ पर उसके पहले सड़क मौजूद थी। सड़क के इस प्रकार के निर्माण को सड़क के पुन: संरेखण के रूप में जाना जाता है।  और जब realignment पूरे रोड प्रोजेक्ट में होता है, तो उस प्रोजेक्ट को realignment प्रोजेक्ट के रूप में जाना जाता है।

Question 21 -  What is the difference between W- Beam type crash barriers and Thrie beam type crash barriers? 
W- Beam टाइप क्रैश बैरियर और Thrie बीम टाइप क्रैश बैरियर में क्या अंतर है?

Answer -
1- W - Beam type steel crash barriers 
 it consists of a steel post and a 3 mm thick W - beam rail element attached to a steel block, which in turn is attached to the steel post. The Barrier is of a semi-rigid type. The steel post and the blocked-out spacer are channel section 75 mm x 150 mm size 5 mm thick. 
The rail shall be 700 mm above the ground and 1100 mm below the ground, and shall be spaced at 2 met. centre to centre. The posts, beam, spacer and fasteners shall be galvanised by the hot dip process. 

2 - Thrie beam Type Steel crash Barrier
 Thrie-Beare type steel barrier design is costlier than the simple W beam type crash barriers, but is less prone to damage by vehicle collisions, especially for shallow angle impacts .
The post and spacer blocks are of steel channel section 75 mm x 150 mm x 5 mm. 
The spacing of the posts is 2 met. centre to centre. The post is 850 mm above the ground and is driven into the ground to a length of 1150 mm. All the steel components and fasteners are galvanised by the hot dip process.

Question  22 -  What is the difference between CTB(CTSB) and GSB(Granular sub base) ?

Answer - 
CTB(CTSB) stands for cement treated sub-base while GSB stands for granular sub-base. 

1 - CTSB/CTB course are capable to carry more loads than granular sub base (GSB).

2  - CTSB/CTB performance is good in rutting and fatigue cracking as compared to GSB. 

3- CTSB/CTB gains strength as time passes even under traffic load but GSB does gain strength as time passes. 

4 - The thickness of CTB(CTSB) is significantly less than GSB layer for same traffic count because CTB (CTSB) has higher modulus. Hence Use of CTB, Reduce the aggregate quantity as compared to GSB.

5 - CTB has longer life as compared to GSB.
 
6 - CTB(CTSB) is best option in low lying water clogged area.

Mukesh Kumar 

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