Civil Engineering: Conventional and Objective Type (2018-19 Session) – An exclusive e-book for civil engineering students

Civil Engineering: Conventional and Objective Type (2018-19 Session) is an exclusive e-book written by R.S.Khurmi and J.K. Gupta. The book is available in paperback format.

The book comprises of 724 pages as well as near about 4800 topic-wise solved and unsolved questions.

The book is considered as a very good resource for undergraduate students of Civil Engineering as they can use the book as reference guide for preparing them for different types of competitive examinations like GATE, UPSC, IAS and IES as well as university examinations.

The book covers the following topics :-

• Oscillations and Waves
• Electrostatics
• Magnetostatics and Electrodynamics
• Electromagnetic Waves
• Light
• Interference
• Diffraction
• Polarization
• Optical activity
• Optical fibres
• Architectural Acoustics

• Ultrasonics
• Electron Emission
• Electron Ballistics
• Electron Optics
• Elements of Thermodynamics
• Thermoelectricity

• Special Theory of Relativity
• Atomic Physics
• Quantum Mechanics
• Atomic Nucleus and Nuclear Energy
• Cosmic Rays and Elementary Particles
• Nuclear Instruments
• Lasers
• Holography
• Crystal Structures
• Crystal Defects
• Conductors
• Band Theory of Solids
• Semiconductors
• Semiconductor Diodes
• Bipolar Junction Transistor
• Dielectrics
• Magnetic Materials
• Superconductivity
• Modern Engineering Materials
• Non Destructive Testing
• Vacuum Technology
• Nanotechnology
• Geometrical Optics
One can purchase the book online from amazon by clicking on the following link 
Civil Engineering: Conventional and Objective Type (2018-19 Session) – An exclusive e-book for civil engineering students
Published By
Arka Roy

Some vital points required for construction bid formation

CAREFUL STUDY OF THE CONTRACT DOCUMENTS: The contract documents which are provided to the contractor or delivered for his inspection comprise of general contract conditions, drawings, specifications, bills of quantities etc.

These documents should have been examined cautiously to ensure whether there are any unusual conditions, specifications as well as any feature of the work which should be taken into consideration throughout pricing.

Sub-contractor’s work: Make relevant quarries about prices with sub-contractors and material suppliers for their relative segments of the job.

Site visit: It is vital to determine the conditions under which the work should have been accomplished and their effect on pricing.

a. Complexity to get entry to the site
b. Restricted space on the site for vehicle movements
c. Type of soil and density of water table
d. Accommodation for space for preserving materials on site
e. Accessibility of materials, their sources and existing market prices
f. Local resources of skilled and unskilled labor, current wages for workmen
g. Source and cost of water required for construction
h. Power and lighting source, and the cost of arranging, preserving and serving power connection to the site.

TIME FOR COMPLETION: The bidder then works out the time period for executing the work and the number and category of permanent staff suitable for the nature of the work for construction management. It facilitates to compute the establishment charges.

TEMPORARY WORKS: The value of any temporary works required to set up the construction and to dispose of on finishing like temporary office necessary for construction management purpose, lay up sheds for building materials, access road, water supply, depreciation of construction equipments, insurances, taxes, etc.

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Some vital points required for construction bid formation

Published By
Arka Roy

How to calculate hinged support, normal thrust and shear of a three hinged circular arch

This construction video tutorial is based structural analysis. You will learn how to make calculation of reaction at the support as well as normal thrust and shear for three hinged circular arch.

This video is presented by renowned engineer Mr. Parag Pal.

Three hinged system:

a. A three hinged system comprises of two plates, attached collectively with a hinge containing two hinged supports A and B resting on the ground.
b. When the plates 1 and 2 comprises of curved bars, the system is known as a three-hinged arch.
c. The distance 1 among the centers of the hinges at the support is known as the span of arch.
d. When distance f from the center of the crown hinge to the straight line going through the former two is defined as its rise.

The reactions of a three hinged arch will be completely established with four parameters, as for example, the amounts of reaction Ha, Hb, Va, and Vb.

So, a three hinged system is always statically determinate.


a. The bending moments and shears operative over cross sections of three hinged arches are significantly smaller as compared to the subsequent stresses in a simple beam covering the equivalent span and bearing the same load. So, three hinged arches are inexpensive relating to ordinary beams, specifically for large span structures.

b. Calculations are very simple as compared to other type of arches.
c. No bending moments are generated at the abutments and the crown since hinges cannot withstand moments.
d. Differential settlements of the supports do not impact stresses, since the pines or hinges allow the arch to assume the slightly different shape consequent upon settlement.

e. The pin joints allow the arch to modify itself to expansions and contractions because of alterations in temperature.

In this video, solution is given to the following problem: A three-hinged circular arch hinged at the springing and crown points contain a span of 40 m and a central rise of 8 m. It bears a consistently distributed load 20 kN/m over the left-half of the span collectively along with a concentrated load of 100 kN at the right quarter span point.

Determine the supports, normal thrust and shear at a section 10 m from left support.

To get the solution, go through the following video tutorial.

How to calculate hinged support, normal thrust and shear of a three hinged circular arch

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Published By
Arka Roy


Some vital plastering defects and remedies to resolve them

Besides, cracking, there may be other flaws with plastering. John Roxburgh who performs lecturer at The Concrete Institute’s School of Concrete Technology, highlights the following points for plastering defects as well as proper solutions for resolving them.

1. Debonding: Plaster, particularly very thick layers, is set to debond from the wall if the exterior skin compresses at a diverse rate except for the plaster touching with the wall. It will be the outcome of insufficient substrate formation.

Areas greater than regarding the size of a plate should have been eliminated and substituted with the following :-

• Cleaning filthy or greasy wall surfaces completely.
• Maintain the exact moisture content for the walls.
• Prior to plastering, apply a cement slurry or spatterdash coat.
• Apply bonding liquids and abide by the method suggested by the manufacturer.

2. Hardness Scarcity: There do not exist any specifications for the hardness or strength of plaster, but soft plaster happens due to the followings:

• Inadequate cement.
• The sand contains unnecessary quantities of dust (in excess of 15% by mass going through the 0,075mm sieve).
• The utilization of a mix with sub-standard water-retention properties.
• The inclusion of supplementary water too long after first mixing (a practice called as re-tempering).

Sometimes, It becomes necessary to provide a slightly lower plaster that occasionally demonstrates vital cracking or debonding, as compared to strong one.

3. Instant drying: Normally, extreme early moisture loss occurs due to the following:

• Evaporation may occur if plastering is done in sun and wind.
• Suction into the walls, when the masonry units are not moistened.
• Apply bad grade sand that does not contain fine material (below 5% by mass passing the 0,075mm sieve).
• Refrain from applying building lime or a masonry cement when there is no fine material in sand.

4. Grinning: Grinning means when the mortar joints are evidently seen through the plaster. It occurs due to the variation in suction among the masonry units and the mortar, along with extraction of mortar joints.

To get rid of grinning, use an undercoat or a spatterdash coat prior to plastering.

5. Expansion: It contains swelling, softening, layer cracking and spalling of the plaster. It happens because of proprietary gypsum-based products in the mix. Under moist conditions, the sulphate from the gypsum reacts with the Portland cement paste and develops compounds of increased volume which mess up the plaster.

Just eliminate and substitute the plaster to get rid of expansion-induced disruption because of gypsum in the mix.

6. Popping: Pop-outs stand for conical fragments that appear on the plaster surface. These happen because of pollutant particles in the mix, which, when react with the moisture in the mix, extend and produce cavities in the plaster.

As soon as the reason for the pop-out is eliminated, the hole is filled with a proprietary filler and painted over.

Article Source:

Some vital plastering defects and remedies to resolve them

Published By
Arka Roy


How to determine the length of a transition curve

In this construction video tutorial, you will learn how to determine the length of a transition curve by applying various methods like definite rate of superelevation, rate of change of radial acceleration and arbitrary gradient.

Definition of transition curve may be given as following :-

The transition curve stands for a horizontal curve with inconstant radius that is applied to attach straight line to circular curve. The radius of curve changes from infinite to certain fix value.

Normally, transition curve is arranged at both ends of the circular curve.

Occasionally, it is also arranged at end of compound curve. It is very effective for transportation engineer, highway engineering and surveyors.

Benefits of transition curve: If there is no transition curve, the risk for overturning of train or truck may occur. This vehicle can skid and leads to accidents on road.

Transition curve contributes to sluggish increase of curvature that facilitates a driver to increase the speed of vehicle. It also allows the vehicle to drive at greater speed in curve.

The following properties should be included in a curve to be qualified as a transition curve :-

• It’s radius should have been infinite at origin on the tangent.
• Where the circular curve coincides at that curve, on that point radius must be equivalent with the radius of circular curve.
• There should not be any divergence among rate of increase of super elevation and the rate of increase of curvature.

The formula of definite rate of superelevation is L = nh/100 (meters)

Where, h denotes superelevation in centimetres and L denotes length of transition curve in meters.

The definite rate of superelevation should be assumed as 1 in n.

The formula of rate of change of radial acceleration is L = v3/ar (meters)

Where, v = speed/velocity of vehicle (m/sec)
a = rate of radial acceleration
L = length of transition curve in meters

The formula of arbitrary gradient is L = hv/a (meters)

Where, v = speed/velocity of vehicle (m/sec)

h = amount of superelevation
a = time rate in centimetres per second

To gather more details, go through the following video tutorial.

How to determine the length of a transition curve

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Published By
Arka Roy




Benefits of vibro compaction for improving the conditions of ground

Particles of granular soil are reorganized by vibration in a manner so that greater density is maintained.

In non cohesive soils (granular soils), the optimal depth of surface compactor and vibratory roller is restricted to a few meters under ground level and large depths can be attained with deep compaction method having depth vibrators. This method is described as Vibro compaction.

The depth vibrator is curtailed into the ground under its own weight supported with water flushing from jets which are placed adjacent to the tip of the vibrator (i.e. bottom jets).It is found that penetration is very suitable when a high water flow rate is utilized, in place of high water pressure.

After achieving the optimal final depth, the bottom jets are closed and flushing sustained by water from jets positioned near the top of the vibrator. These jets lead water completely outside, facilitating the adjacent sand to run into the space around the vibrator. The vibrator is retained at the final depth unless either the power consumption of the vibrator attains pre-determined amperage or the pre-set time intervals are lapsed, generally+ 30–60sec, whomever is the sooner.

When the amperage/time criterion is fulfilled, the vibrator is elevated to a pre-determined height, generally 0.5–1.0m, and again is retained in position for the pre-set time or unless the amperage attains the target level, whichever is earlier.

The vibrator is then elevated for the next compaction step and this procedure goes on stepwise unless the vibrator attains the surface.

Due to Vibro compaction, the occurred settlement may vary from 5% to 15% of the compaction depth based on the original density and the required density. A schematic that demonstrates the step-by-step installation process of Vibro compaction is provided.

If Vibro compaction is utilized for bigger areas, it is usually executed by either a triangular or rectangular grid pattern having probe spacing in the range of 2m to 4m c/c.

The spacing is based on various factors, along with the soil type, backfill type, probe type and energy, and the level of improvement necessary.

For more information, go through the following video tutorial.

Benefits of vibro compaction for improving the conditions of ground

Published By
Arka Roy


How to set up line and grade in sewer sanitary system construction

n order to place grade and line for developing the sanitary sewer system, four methods are mostly applied. One of these methods or combination thereby may be utilized in the construction. Given below, the detail information on these methods.

Methods of Setting Line and Grade in Construction of Sewer Sanitary System:

1. Stakes or crosses are set up on the surface on an offset from the centerline of sewer sanitary
2. Stakes are set in the bottom of the trench on the sanitary sewer line since the rough grade for the sanitary sewer is finished.
3. Elevations provided for the finished trench grade and sanitary sewer invert whereas sanitary sewer construction proceeds.
4. A laser beam of light set in the manhole or a particular height over sanitary sewer flow line.

1. Stakes or crosses set up on the surface on an offset from the centerline of sewer sanitary: In general, this method is very effective for small diameter sewer sanitary system. Substantially, crosses, stakes, or spikes are arranged at a consistent offset from sewer sanitary centerline.

The excavated soil material should remain at one side of the sewer sanitary trench and the stakes should be arranged at the other side.

If it is required to accomplish an accurate and reasonable job, there should be perfect sheet on which reference points of sanitary sewer stations, offset, and vertical distance from each reference point from projected sanitary sewer invert will have to be recorded.

Finally, the line and grade of sewer sanitary is transmitted to the bottom of the trench with tape and plumb bob unit or tape and level.

2. Stakes are set up in the bottom of the trench on the sanitary sewer line because the rough grade for the sanitary sewer is finished: This method is ideal for large diameter sanitary sewer as well as the sloped trench wall.

For the sloped trench wall, the top width of the trench should have been significantly wide, and the deployment of short offset would not be recommended.

Under this method, surface references are transmitted to the stakes which are arranged at the bottom of trench along sanitary sewer system.

When stakes are set up at the trench bottom, string line should have been drawn among at least three points. The string line should be examined by applying the same process for batter boards.

How to set up line and grade in sewer sanitary system construction

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Published By
Arka Roy


Details of Cracking in Concrete

If cracks occur in concrete on regular basis, the appearance of the concrete becomes unpleasant as well as the structure of the concrete becomes feeble.

The cracking can be managed with reinforcement and joints. With foul cracking, the reinforcement is uncovered to air and moisture which may cause rust as well as reduce the strength.

Types of Cracks: Two types of cracks occur in reinforced concrete

Pre-Setting Cracks: It develops prior to solidification of concrete whereas it is still executable.

Hardened Cracking: Here, crack develops as soon as the concrete gets solidified.

Pre-Setting Cracks: Pre-setting cracks mainly develop at the time of placing, compaction and finishing resulting from movement of concrete prior to it gets dried.

The following types of pre-setting cracks mainly exist:

Plastic Settlement cracks
Plastic Shrinkage cracks
Cracks resulting from Movement of The Formwork.

When pre-setting cracks occur, examine them carefully so that they can be easily restrained whereas the concrete is still setting.

If these are identified at the initial stage, fixing is done easily with re-compacting, re-trowelling or re-floating the concrete surface.

Plastic Settlement Cracks: These types of cracks develop once the concrete is arranged, whereas it is still plastic. They become larger as concrete dries and shrinks and like to follow the lines of reinforcement.

Re-vibrate the concrete.
Re-trowel the surface.

Search for cracks when the concrete is setting. At this stage, these can be easily settled.

Plastic Shrinkage Cracks: Usually cracking occurs in summer but it may also happen throughout winter. Plastic shrinkage cracks become visible in lines, roughly parallel or in a crazed haphazard way. They are generally 300–600 mm long but may be among 25 mm and 2 m in length.

Prevention: Moisten the subgrade and forms and safeguard concrete from the wind. Retain all materials cool on hot days.

Set, compact and cure in quickest possible time on hot days in order that concrete won’t dry out.

As soon as the concrete is condensed, screeded and floated, use a consistent spray film of EVAPORATIVE RETARDANT (Aliphatic Alcohol) to avoid quick loss of surface moisture, then continue with finishing.

It is recommended to set concrete at the cooler times of the day.

Repair Cracks is closed with alteration in the plastic concrete.

For more information, go through the following link

Details of Cracking in Concrete

Published By
Arka Roy


Method of constructing post tension RCC slab

In this construction video tutorial, you will learn how post tension RCC slabs are built up as well as how post tensioning is performed and benefits of post tensioning process.

POST TENSION SLAB: It refers to the slab that is tensioned as soon as the slab is developed. Reinforcement is arranged to avoid the compression.

In Post tension slab, cables or steel tendons are utilized to substitute the reinforcement. Post-tensioning offers a solution to get rid of the natural weakness of concrete in tension as well as optimize its strength in compression.

In concrete structures, this is obtained by arranging high-tensile steel tendons/cables in the element prior to start the casting. If the concrete attains the required strength, the tendons are pulled with special hydraulic jacks and retained in tension with specially designed anchorages which are attached at each end of the tendon.

It creates compression at the edge of the structural member that increases the strength of the concrete for resisting tension stresses.

If tendons are correctly curved to a specific profile, they will exert, other than compression at the perimeter, a useful ascendant set of forces (load balancing forces) that will neutralize applied loads, alleviating the structure from a portion of gravity effects.

In this type of concrete slab, cables are affixed in place of reinforcement. In Steel reinforcement the gapping among bars is 4inch to 6inch while in Post tension slab the gapping is in excess of 2m.

Go through the following video tutorial, to get more details on post tension slab.

Method of constructing post tension RCC slab

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Published By
Arka Roy


Benefits of raft foundation

Raft foundation stands for a type of foundation developed for the reinforced concrete slab having consistent thickness (150 mm to 300 mm) that expands over the large area particularly whole footprint of the building.

It provides support to the columns or walls and transmits the load from structure to large area of ground. Once it is built up, it seems mat of concrete extends over large area, as a result it is also known as mat foundation.

The slab bears the load of entire building and delivers it to ground, so it is assessed to float on ground similar way the raft floats on ground.

Raft Foundation is effective under the following situations :-

When the soil at site contains a low bearing strength, thus load required for being allocated over big area.

When it is ineffective to arrange individual or any other type of foundation. As for instance, when the strip foundation would encompass 50% or more area of building footprint, in such conditions raft foundation is very useful.

When there are chances for unnecessary settlement or differential settlement, when other type of foundation is arranged. In this way, settlement chances are minimized by setting up raft foundation.

When the soil situated below is unstable and might comprise of pockets of easily compressible soil, which may lead to individual footing failure. By arranging raft foundation, this risk is reduced.

If it is required to build up basement, raft foundation is necessary. It’s unreasonable and creates various issues if other types of foundation are arranged except for raft foundation at the time of providing basement. Raft foundation is very suitable for transmitting load and also functions as a floor for basement.

Why raft foundation is necessary if the bearing strength of soil is low?

Generally, it is found that if the soil contains low bearing strength, the raft foundation is arranged at site.

Benefits of raft foundation.

Raft foundation transmits the total load of the building to the soil below.

The deign of raft foundation is simple.
The total load on building (dead + live + other loads + self weight of building and foundation) is estimated.

This total load of building is divided with total area of foundation (i.e. footprint of building). It provides us stress on per sq.m of soil.

For raft foundation the load transfer area of footing is much more as compared to the other types of foundation, therefore, the stress on soil is much lesser, thus it can be avoided by soil having low bearing capacity. The risk of shear failure can also be resisted.

To get more information on raft foundation, go through the following link

Benefits of raft foundation

Published By
Arka Roy