Factors That Influence Water Consumption

8/21/2019 Factors That Influence Water Consumption

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Factors that influence water consumption:

Consumer Groups:

• Domestic and public use

• Industrial and commercial use

• Livestock use

• Waterworks use

• Losses and wastes ('unaccounted for' water)

• Fire demand

Factors influencing water use:

• Size of city

• Climate and location

• Industrial development

• Habits and living standards

• Parks and gardens

• Water quality

• Water pressure

• Cost of water

Essential elements of water supply

• Source of supply

• Collection system• Treatment plant

• Distribution system

The most common water treatment methods are

• Plain sedimentation

• Sedimentation with coagulation

• Filtration

• Disinfection

Treatment process for removal of impurities

• Aeration

• Water softening

• Arsenic removal

• Iron removal

• Activated carbon application

• Fluoridation and de-fluoridation

• Demineralization

• Desalinization

The following are different types of wells

• Shallow wells


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• Deep wells

• Tube wells

• Artesian wells

Sewage

• Sanitary/Domestic• Industrial

• Storm

Sewer

Pipe of conduit which carrying sewage

• Sanitary or separate sewer

o Sanitary sewage

o Industrial sewage

• Storm sewer

• Combined sewer

Hardness

Hardness in water is principally caused by the solution in water of carbonate,

bicarbonate and sulfate or calcium and magnesium. Sometimes iron and

aluminum cause hardness to a lesser degree.

Methods used for water softening

• Heating

• Freezing

• Lime process• Lime and soda ash process

• Excess Lime treatment

• Caustic soda process

• Base exchange process

• Zeolete process

• Demineralization or exchange process.

Effects of Hardness

• Enough consumption of soap

• Clogs skin, discoloures porcelain, stains and shortens fabrics, toughens and

discolours vegetables

• Gives difficulty in textile and paper manufacture, tannery and other

industrial processes.

• Form scales in boilers, resulting in great heat transfer losses and danger of

boiler failure.

• Very hard water is not palatable

Water transmission and distribution system

•

Gravity flow system• Direct pumping


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• Pumping and Storage system

Different types of pipes

• Cast Iron

• Steel

• Pre-stressed concrete• R.C.C

• Water Supply Engineering

• A.C. Pipes

• Galvanized Iron (G.I)

• P.V.C and plastic pipes

Diseases transmitted by fly

• Typhoid fever

• Paratyphoid fever

• Bacillary dysentery

• Amoebic dysentery

• Infantile diarrhea

• Pinworm

• Roundworm

• Whipworm

• Hookworm

• Tapeworm

Test for environmental engineering

• Determination of Iron Concentration of Water

• Determination of Sulfur from a Soluble Sulfate Solution

• Determination of P H

of water

• Determination of Total Dissolved Solid (TDS)

• Determination of Alkalinity of Water

• Determination of Ammonia in an Ammonium Salt

• Determination of Chlorine Concentration of Water

• Determination of Arsenic• Determination of Hardness of Water

• Determination of Dissolved Oxygen

• Determination of Biochemical oxygen demand (BOD)

• Determination of Chemical oxygen Demand (COD)

• Determination of Turbidity of Water

Pumps classification:


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By types of service

o Deep well pumps

o Low lift pumps

o High lift pumps

o Booster pumpso Fire service pumps

o Stand by pumps

By power source

o AC powered pumps

o DC powered pumps

o Oil powered pumps

o Gas powered pumps

o Diesel powered pumpso Solar water pumps

o Hand pumps

o Electromagnetic pumps

o Hydraulic ram pumps

o Steam pumps

By Mechanical principal of operation

o Reciprocating or Displacement pumps

o Centrifugal pumps (Roto-dynamic pumps)• Drinking water Standards

Quality WHO (mg/l) (ppm)

Total Dissolved Solids 500

Turbidity 5

Colour 15

Temperature 50°

Taste and Odour Water should be completely free from taste and

odour

Arsenic ( As ) 0.005

Chloride (C i) 200


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P H

7 – 8

Iron ( Fe ) 0.25

Nitrate ( N O3 ) 50

Manganese ( Mn) 0.05

Sulphate ( SO4 ) 200

Calcium (Ca ) 75

Zinc(Zn )

5

Magnesium ( Mg) 75

Chromium(Cz )

0.05

Cadmium (Cd ) 0.005

Copper(Cu )

1.0

Barium(Ba )

1.0

Cyanide(Cn )

0.01

Fluoride 0.5

Silver( Ag )

0.05

Total Hardness 100

Total Alkalinity 100


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Future Population

Pf = P p (1+r )n

Where, Pf = Future population

P p= Present population

r=rate of yarly population growt h

n= Number of years¿be onsidered

General characteristics of groundwater and surface water

Ground Surface

Constant composition Varying composition

High mineralization Low mineralization

Little turbidity High turbidity

Low or no color Color

Bacteriologically safe Microorganism present

No dissolved oxygen Dissolved oxygen

High hardness Low hardness

H2S, Fe. Mn Tastes and odorsPossible chemical toxicity

SPT Test (ASTM – D1586-58)

The SPT consists of driving a 2-inch outside diameter and 1.5 inch diameter “Split

Barrel” sampler at the bottom of an open borehole with a 140-lb (63.5 kg) hammer

dropped 30 inch. The sample tube is driven 6 inch into the ground and then thenumber of blows needed for the tube to penetrate each 6 inch up to a depth of 18

inch is recorded. The number of blows required to achieve the final 12 inch

penetration is the Standard Penetration resistance, N. The “N” value is the number

of blows to drive the sampler the last 12 inch, expressed in blows per foot,

expressed in blows per foot. After the penetration test is completed, the sampler is

retrieved from hole. The split barrel is opened, the soil is classified, and a moisture

specimen is obtained. After the test, the bore hole is extended to the next test

depth and the process is repeated.


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Different types of test for finding properties of soil.

•Static Pile Load Test (Axially Loaded Compression/Tension, TransversallyLoaded)

• Pseudo-Static Pile Load Test (Axially Loaded Compression)

• Dynamic Pile Load Test (Axially Loaded Compression)

• Plate Load Test on Soil Ground

• Plate Load Test on Soils for Road

• Rigid Plate Load Test on Rocks

• Large Plate Load Test with Repeat Anchor

• Plate Load Test for Deep Piers

• Plate Load Test for Deep Borehole

Laboratory Tests of Soil

Properties Test

Grain size distribution Sieve analysis and hydrometer test

Consistency Liquid limit

Plastic limit

Plasticity index

Compressibility Consolidation

Compaction Characteristics Standard proctor, Modified proctor

Unit Weight Specific Gravity

Shear Strength

1.Cohesive Soils

2.Non-cohesive soils

3.General

Corresponding Tests:

1.Unconfined Compression test

2.Direct Shear test

3.Tri-axial test

Field Tests of Soil

Properties Test

Compaction control • Moisture – Density relation

• In place density

Shear Strength – (Soft Clay) Vane shear test


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Relative Density – (Granular Soil) Penetration test

Field density • Core Cutting

• Sand replacement

Permeability Pumping test

Soil Sampling and resistance of thesoil to penetration of the sampler

Standard Penetration testSplit Barrel Sampling

Bearing Capacity

• Pavement

• Footing

Corresponding Tests

• CBR, Plate Beating test

• Plate Bearing test

Piles

• Vertical Piles

• Batter Piles

Corresponding Tests

• Load Test

• Lateral Load Test

Methods of boring

• Wash boring

• Rotary drilling

• Percussion drilling

• Auger boring

• Core Boring

Coefficient of compressibility

• The ratio of void ratio difference to the effective pressure difference of two

different loadings during primary consolidation.

Geo-textiles

A synthetic fabric used to stabilize soils, retain soils, prevent the mixing of

dissimilar soils, provide a filtering function, pavement support, sub gradereinforcement, drainage, erosion control and silt containment. SeeGeo-synthetics

for additional information and publications.

N-Value

Also, standard penetration resistance. The number of blows required to drive a

split-spoon sampler during a standard penetration test a distance of 12 inches

(0.305 m) after the initial penetration of 6 inches (0.15 m).

Standard Penetration Test (SPT)

http://www.geotechnicalinfo.com/geosynthetics.htmlhttp://www.geotechnicalinfo.com/geosynthetics.html


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A field test that measures resistance of the soil to the penetration of a standard

split-spoon sampler that is driven 12 inches (0.3 m) with a 140-pound (63.5 kg)

hammer dropped from a height of 30 inches (0.76 m). The N-value is derived from

this test.

Physical properties

• Density, porosity, voids content, moisture content, specific gravity,

permeability and structure (micro or macro).

Mechanical properties

• Strength, a measure of maximum load per unit area, stiffness measure of

deformation capacity. Hardness.

Chemical properties

• Composition, potential reaction

Thermal properties

• Coefficient of thermal expansion, thermal conductivity

Electrical

• Electrical conductivity

Magnetic

• Magnetic permeability

Acoustical

• Sound transmission

Optical

• Colour, light transition, light reflection

For each the above properties, there is a characteristic type of stimulus capable of

provoking different responses.

Terminology of Properties

Brittleness: The tendency of a material to break with little or no elongation before

it undergoes plastic deformation. Materials that fail in tension at relatively low value of strain are classified as brittle materials.

Ductility: The ability of certain materials to be plastically deformed without

fracture. It is the physical property of being capable of sustaining large plastic

deformations without fracture.

Elasticity: The ability to deform and return to the unreformed shape. This follows

hooks law.

Hardness: The resistance to deformation and forced penetration. In materialsscience, hardness is the characteristics of a solid material expressing its resistance


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to permanent deformation. In other words, Hardness is the resistance to wear. It is

measured by Mohs scale.

Malleability: The ability of a material to take a new shape when hammered or

rolled.

Tensile strength: The maximum tensile load that can be applied before a material

fracture.

Toughness: The ability to withstand cracking, as opposed to brittleness.

Toughness is the ability to absorb energy in the plastic range. It is the resistance of

a materials to fracture when stressed.

Yield Strength: The load at which the material stops elastically deforming, and

starts permanently deforming.

Stiffness:It is the resistance to deform in the elastic range. Stiffness is the

resistance of an elastic body to deflection or deformation by an applied force. The

stiffness K of a body that deflects a distance d under an applied force P is

! = P

"

Unit: Force per unit length

Modulus of Resilience: The area under the elastic part of the stress strain curve.

Modulus of Toughness: The area under the entire stress strain curve.

Stress: The intensity of force (that is, the force per unit area) is called stress.

Mathematically,

Stress, # = P

A

Normal Stress: The stress acting perpendicular to the cut surface is called normal

stress.

Strain: The change in length or deformation is referred as Strain. The resulting

state of stress and strain is called uniaxial stress and strain.

Mathematically, the ratio of change in shape to the original shape is termed strain.


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Strain, ε¿

$

%

Where,

ε = Strain

δ = Deformation

L = Length

Exercise: A prismatic bar with a circular cross section is subjected to an axial

tensile force of 100 KN. The measured elongation is d = 1.5 mm. Calculate the

tensile stress and strain in the bar.

Solution

Stress,# =

P

A

¿ 100

&'252

4

=203.72 N/mm2= 204 MPa

Strain, ε¿

$

% =¿

1.50

3.5'1000=0.0004286

=4.3×10-4

Longitudinal strain: The ratio of change in length to the original length is termedlongitudinal strain.

Shearing strain: Shearing strain is defined as the angle of shear measured in

radians.

Shear force: Shearing is defined as a force that works perpendicular to the

extension of an object. Shearing force is other than tensile or compressive force

which acts parallel to a plane and produce sliding or skewing type of deformation.

Shear Stress: The intensity of internal distributed force that is parallel to the

surface of an imaginary cut surface is called the shear stress on the surface.

Shearing stress is a stress where the stress is parallel to a force of the material to

prevent sliding.

It is denoted by τ,

τ =S h ear fore

Area under s h ear


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Hooks Law: Within theelastic limit of a solidmaterial, thedeformation (strain)

produced by aforce (stress) of any kind isproportional to the force. If the elastic

limit is not exceeded, the materialreturns to itsoriginal shape and size after the

force is removed, other it remains deformed or stretched. The force at which the

material exceeds its elastic limit is called 'limit of proportionality. Discovered in1676 by the UK scientist andinventor Robert Hooke (1635-1703).

In generalized form, Hooke's law in says thatstrain is directly proportional to

stress.

σ =E. ε

E is a constant known as the modulus of elasticity or Young Modulus.

Young Modulus: Young's Modulus also known as the Elasticity Modulus of a

material is the ratio of the stress versus the strain within the Elastic region of the

Stress-Strain diagram.

Elasticity Modulus = Stress / Strain

This is usually found from the slope of the stress vs. strain curve.

Modulus of rigidity or shear modulus:It is the shearing modulus of elasticity,

which according to hooks law is the constant of proportionality between shearing

stress and shearing strain within elastic limit. It is denoted by Es or G.

Esor G =S h earing Stress

Shearing Strain = (

2(1+ ))

Where,

E = Young’s modulus

μ = Poisson’s ratio

Poisson’s Ratio: It is the ratio of lateral strain to longitudinal strain. It is denoted

by μ, )=

* +

* y

Displacement: The total movement of a point with respect to a fixed reference

coordinates is called displacement.

http://www.businessdictionary.com/definition/elastic-limit.htmlhttp://www.businessdictionary.com/definition/material.htmlhttp://www.businessdictionary.com/definition/deformation.htmlhttp://www.businessdictionary.com/definition/strain.htmlhttp://www.businessdictionary.com/definition/force.htmlhttp://www.businessdictionary.com/definition/stress.htmlhttp://www.businessdictionary.com/definition/proportional.htmlhttp://www.businessdictionary.com/definition/returns.htmlhttp://www.businessdictionary.com/definition/original.htmlhttp://www.businessdictionary.com/definition/inventor.htmlhttp://en.wikipedia.org/wiki/Strain_(materials_science)http://en.wikipedia.org/wiki/Stress_(mechanics)http://www.businessdictionary.com/definition/elastic-limit.htmlhttp://www.businessdictionary.com/definition/material.htmlhttp://www.businessdictionary.com/definition/deformation.htmlhttp://www.businessdictionary.com/definition/strain.htmlhttp://www.businessdictionary.com/definition/force.htmlhttp://www.businessdictionary.com/definition/stress.htmlhttp://www.businessdictionary.com/definition/proportional.htmlhttp://www.businessdictionary.com/definition/returns.htmlhttp://www.businessdictionary.com/definition/original.htmlhttp://www.businessdictionary.com/definition/inventor.htmlhttp://en.wikipedia.org/wiki/Strain_(materials_science)http://en.wikipedia.org/wiki/Stress_(mechanics)


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Deformation: The relative movement of a point with respect to another point on

the body is called deformation.

Creep: Creep is defined as the increase in the strain under a sustained constant

stress after taking into account other time dependent deformations not associated

with stress. I.e., shrinkage, swelling and thermal deformations. Creep is the term

used to describe the tendency of a material to move or to deform permanently to

relieve stress. Development of strains over long periods of time is called creep.

Relaxation:It is opposed to creep. The time depended decrease of stress in any

material termed relaxation.

Fatigue: When cyclic loading is applied to a material, failure may occur at a stress

much lower than the strength under static loading. This apparent weakening of

the material is called fatigue.

Resilience:It is the ability to absorb energy in the elastic range. Resilience is

defined as the capacity of a material to absorb energy when it is deformed

elastically and then, upon unloading to have this energy recovered. It is

represented by the area under the curve in the elastic region in the stress strain

diagram.

What is the difference between stress and strength?

o The intensity of force (that is, the force per unit area) is called stress. But

the strength is a stress at which the material fails is called the strength.o Therefore any strength is a stress but any stress is not strength.

Bearing Stress: The compressive normal stress that is produced when one surface

presses against other is called the bearing stress.

Strength: The stress at which the materials fails or ruptures (rupture is the

process of breaking open or bursting) is called strength.

Compressive Strength: The maximum compressive stress a material can withstand without failure.

Crushing Strength: The compressive stress required to cause a solid to fail by

fracture; in essence, it is the resistance of the solid to vertical pressure placed

upon it.

Fatigue Strength: The maximum stress a material can endure for a given number

of stress cycles without breaking. Also known as Endurance Strength.


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Flexural Strength:Strength of a material in bending, that is, resistance to

fracture.

Hydrostatic Strength: The ability of a body to withstand hydrostatic stress.

Impact Strength: Ability of a material to resist shock loading.

Shear Strength: The maximum shear stress which a material can withstand

without rupture.

Tensile Strength: The maximum tensile stress a material can withstand without

failure.

Ultimate Strength: The tensile stress, per unit of the original surface area, at

which a body will fracture, or continue to deform under a decreasing load.

Yield Strength: The stress which a material exhibits a specified deviation from

proportionality of stress and strain, that is, it indicates the end of elasticity and

the beginning of plasticity.

Proportional limit: The point up to which the stress and strain are linearly

related is called the proportional limit.

Ultimate stress: The largest stress in the stress strain curve is called the ultimate

stress.

Rupture stress: The stress at the point of rupture is called the fracture or rupture

stress.

Elastic region: The region of the stress-strain curve in which the material returns

to the unreformed state when applied forces are removed is called the elastic

region.

Plastic region: The region in which the material deforms permanently is called theplastic region.

Yield stress: The point demarcating the elastic from the plastic region is called the

yield point. The stress at yield point is called the yield stress.

Plastic strain: The permanent strain when stresses are zero is called the plastic

strain.

Necking: The sudden decrease in the area of cross-section after ultimate stress iscalled necking.


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Bending Stress

o When a member is loaded with some external loading, moment & shear

force are set up at each strain. The bending moment at a section tends to

deflect the member & internal stresses tend to resist its bending. This

internal resistance is known as bending stresses.f =

M,

-

Where, M = Moment at onsidered setion .

f = (+treme fiber stresses at onsidered setion .

- = Moment of inertiaat t h at setion .

, = (+treme fiber distane ¿neutrala+is .

f ma+= Ma+imum stress at t h e fart h est fiber i . e at , ma+¿neutrala+is

Fine Aggregate: The aggregate particles passing through sieve #4 (ASTM) and

retained in #200 sieve is called fine aggregate. The standard sieve sizes are #4, #8,

# 16, #30, #50, #100 and #200. The opening sizes of sieves are 4.75 mm, 2.36

mm, 1.18 mm, 600 µm, 300 µm, 150 µm and 75 µm respectively. The FM value of

fine aggregates varies up to 3.0. For usual construction work the value of FM of

fine aggregates i.e. fine & coarse sand varies within 1.2 – 2.5.

Coarse Aggregate: The aggregate particles retaining through sieve #4 (ASTM) is

called coarse aggregate. The standard sieve opening sizes are 75 mm, 63 mm, 50

mm, 37.5 mm, 25 mm, 19 mm, 12.5 mm, 9.5 mm respectively. The FM value of

coarse aggregate greater than 3. This value has an important effect on the

workability of fresh concrete. For usual construction work the value of FM of

coarse aggregate i.e., khoa varies within 4 – 5.

Chemical analysis of good brick clay should give the following chemical

composition.


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Compounds Percentage

Silica 55%

Alumina 30%

Iron oxide 8%

Magnesia 5%Lime 1%

Organic

matters

1%

Total 100%

The following are the characteristics of good bricks:

i.Bricks should be uniform in color, size and shape. The standard dimension is

240 x 115 x 70mm. (9.5 x 4.5 x 2.75 inches)

ii. They should be sound and compact.

iii.They should be free from cracks and other flaws such as air bubbles, stone

nodules, etc.

iv.They should not absorb more than about 115 of their own weight of water

when immersed in water for 24 hours 05 to 20% of dry weight).

v.The average compressive strength of bricks should be in the range of 2500 psi

(as per 'LGED Road Structure Manual-B').

vi.The percentage of soluble salts (Sulphates of Calcium, Magnesium.. Sodium

and Potassium) should not exceed 2.5% in burnt bricks. Because the

presence of excess soluble salts causes efflorescence.

vii.They should be neither over-burnt nor under-burnt.

viii.The weight should be generally 2.7Kg (6 lb.) per brick and the unit weight

should be generally 2000 Kg/in' (125 lbs. /cft).

ix.They should have low thermal conductivity as it is desirable that the buildings

made of them should be cool in summer and warm in winter.

x.They should be non-inflammable and incombustible.

xi.Bricks should not change in volume when wet.


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xii.They should give clear ringing or metallic sound when struck by another

brick or hammer.

Field Testing of Bricks

The following tests may be performed for quick and rough determination of the

quality of brick:

1.Take a brick and try to make a mark on its surface with nail. If you can do

this, it is not a good brick. If not, it is sufficiently hard and compact.

2.Take a brick and strike it with a hammer or another brick. If it gives a clear

ringing or metallic sound, it is a good brick.

3.Surfaces of good bricks should be smooth having square edges, and freefrom cracks and voids.

4.Color, shape, size and structure of bricks should be uniform.

5.Take two bricks and form a 'T' as shown in the following figure and drop

from a height of 1.2m (4 ft.) to 1.5m (5 ft.) on a more or less solid surface. If

they break, they are not good bricks. If they remain unbroken, they are

good bricks.

Cement is typically made from limestone and clay or shale and sand. Theseraw materials are extracted from the quarry, crushed to a very fine powder and

then blended in the correct proportions.

General constituent of cement:

Ingredient Limits

Lime 58-65%

Silica 20-25%Iron- oxide 4-11%

Magnesia 0-4%

Sulphar trioxide 0-1.75%

Alkali 0-3%

Portland cement consists of five major compounds and a few minor compounds.

The composition of a typical Portland cement is listed by weight percentage in

Table.


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Cement Compound Weight

Percentage

Abbreviatio

nChemical Formula

Tri calcium silicate 50 % C3S Ca3SiO5 or 3CaO.SiO2

Di calcium silicate 25 % C2S Ca2SiO4 or 2CaO.

SiO2

Tri calcium aluminate 10 % C3 A Ca3 Al2O6 or 3CaO . Al2O3

Tetra calcium

aluminoferrite10 %

C4 AF Ca4 Al2Fe2O10 or

4CaO. Al2O3.Fe2O3

Gypsum or Calcium

Sulphate5 % CaSO4

.2H2O

Initial setting time indicates the beginning of the setting process when the cement

paste starts losing its plasticity.

Final setting time is the time elapsed (passed by) between the moment water is

added to cement and the time when the paste completely lost its plasticity and can

resist certain definite pressure.

These times of set are tested according to standardized procedures and have no

special relationship to concrete setting behavior. ASTM C 150 Specified Set Times by Test Method

Test Method Set Type Time Specification

VicatInitial 45 minutes

Final 375 minutes

Chemical Properties

•Chemical analysis

• Compound composition

• Chemical limits

Physical Properties

• Fineness

• Soundness

• Consistency

•Setting time

• False set and flash set


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• Compressive strength

• Heat of hydration

• Loss on ignition

• Density

•Bulk density

• Sulfate expansion

Fineness of cement is also important; it affects:

• Rate of hydration

• Rate of setting

• Rate of hardening

• Durability• Rate of carbonation during storage

• Cost

• Rate of gypsum addition

• Bleeding

American Society for Testing Materials Standard (ASTM C-109)

3 -days 1740 psi (12.0 MPa)

7 -days 2760 psi (19.0 MPa)

28 -days 4060 psi (28.0 MPa)

The compressive strength is governed by the following factors:

• w/c ratio

• characteristics of cement

• characteristics of aggregates

• time of mixing

• degree of compaction


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• temperature and period of curing

• age of concrete

• air entertainment

• conditions of testing

• Allowable slumps for various constructions

Type of Construction

Slumps

mm Inch

RCC Foundation walls & Footings 25 – 75 1 – 3

Plain Footings, caissons & substructure walls 25 – 75 1 – 3

Slabs, beams & reinforced walls 25 – 100 1 – 4

Building columns 25 – 100 1 – 4

Pavements 25 – 75 1 – 3

Heavy mass constructions 25 - 50 1 – 2

Admixture

1.Increase workability without increasing water content or decrease the

water content at the same workability;

2.Retard or accelerate time of initial setting;

3.Reduce or prevent shrinkage or create slight expansion;

4.Modify the rate or capacity for bleeding;

5.Reduce segregation;

6.Improve pump ability;

7.Reduce rate of slump loss;

8.Retard or reduce heat evolution during early hardening;


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9. Accelerate the rate of strength development at early ages;

10.Increase strength (compressive, tensile, or flexural);

11.Increase durability or resistance to severe conditions of exposure,including application of deicing salts and other chemicals;

12.Decrease permeability of concrete;

13.Control expansion caused by the reaction of alkalies with potentially

reactive aggregate constituents;

14.Increase bond of concrete to steel reinforcement;

15.Increase bond between existing and new concrete;

16.Improve impact and abrasion resistance;

17.Inhibit corrosion of embedded metal; and

18.Produce colored concrete or mortar.

1. Classification based on size:-

Sand is commonly divided into five sub-categories based on size:

a) Very fine sand (1/16 - 1/8 mm)

b) Fine sand (1/8 mm - 1/4 mm)

c) Medium sand (1/4 mm - 1/2 mm)d) Coarse sand (1/2 mm - I mm), and

e) Very coarse sand (I mm. - 2 mm).

Bulking of Sand

This is increase in the volume of a given weight of sand due to the Presence of

moisture. For up to about 5 to 8 Percent Of moisture by weight of sand there is a

steady increase in volume to about 20 to 30%. The bulking of sand for small


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moisture content is due to the formation of thin film of water around the sand

grains and interlocking the air in between the sand grains and the film of water.

The key factors affecting durability out of many factors:

• Water Cement Ratio

• Deterioration (Steel Corrosion)

• Drying Shrinkage

• Freezing and Thawing Action

• Chemical Attack

1.Classify soil Based on grain size.

Classification System or

Name of the organization

Particle size (mm)

Gravel Sand Silt Clay

Unified 75 – 4.75 4.75 – 0.075 Fines (silts and clays) < 0.075

AASHTO 75 – 2 2 – 0.05 0.05 – 0.002 < 0.002

MIT > 2 2 – 0.06 0.06 – 0.002 < 0.002

ASTM > 4.75 4.75 – 0.075 0.075 – 0.002 < 0.002

2.Write the ASTM Standard Sieve Opening Size

ASTM Standard Sieve no Sieve opening micron (0.001mm) Inches

4 4.75 0.1870

6 3.35 0.1319

8 2.36 0.0929

10 2.00 0.0787

16 1.18 0.0465

20 850 µm 0.0335

30 600 µm 0.0236

40 425 µm 0.0167

50 300 µm 0.0118


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60 250 µm 0.0098

100 150 µm 0.0059

140 106 µm 0.0042

200 75 µm 0.003

3.What is Effective Size, coefficient of curvature & uniformity coefficient?

This parameter is the diameter in the particle size distribution curve

corresponding to l0% finer. The effective size of a granular soil is a good

measure to estimate the hydraulic conductivity and drainage through soil

Uniformity Coefficient

C u= /

60

/10

Coefficient of Curvature

C = /30

2

/60 ./10

Where /

60 , /

30 and /

10 are the diameters corresponding to percents

finer than 60, 30, and 10% respectively.

4.Show D60, D30 and D10 with graph.


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0

10%

20%

40%

30%

50%

60%

% F i n e r b y M a s s

70%

80%

90%

100%

Grain Size, D (mm)

10 1

10D

60D

30D

01

5.Define Consistency Limits (Atterberg limits).

Consistency Limits may be defined as” The moisture contents of a soil at the

points where it passes from one stage to the next are called consistency

limits or Atterberg limits.”

On the other hand, “The moisture content, in percent, at which the soil

changes from a liquid to a plastic state, is defined as the liquid limit (LL).

The moisture content, in percent, at which the soil changes from a plastic to

a semisolid state and from a semisolid to a solid state are defined as the

plastic limit (PL) and the shrinkage limit (SL), respectively. These limits are

referred to as Atterberg limits”.

6.Difference between Compaction & Consolidation

Compaction Consolidation

• It is a dynamic Process • It is a static Process

• Volume reduction by removing of air

voids from soil grains

• Volume reduction by removing of

water from soil grains

• It is almost instantaneous

phenomenon

• It is time dependent phenomenon

• Soil is Unsaturated • Soil is always saturated

• Specified Compaction techniques

are used in this process.

• Consolidation occurs on account of

a load placed on the soil


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7.Briefly describe different types of gradation of soil particle with graph.

Well or Dense gradation

A well gradation is defined as a sample that is approximately of equalamounts of various sizes of aggregate. By having a well gradation, most of

the air voids between the materials are filled with particles. A dense

gradation will result in an even curve on the gradation graph.

Uniform gradation

Uniform gradation is defined as a sample that has aggregate of

approximately the same size. The curve on the gradation graph is very steep,

and occupies a small range of the aggregate.

Gap gradation

A gap gradation refers to a sample with very little aggregate in the medium

size range. This results in only coarse and fine aggregate. The curve is

horizontal in the medium size range on the gradation graph.

Open gradation

An open gradation refers an aggregate sample with very little fine aggregate

particles. This results in many air voids, because there are no fine particles

to fill them. On the gradation graph, it appears as a curve that is horizontal

in the small size range.

Rich gradation

A rich gradation refers to a sample of aggregate with a high proportion of

particles of small sizes.


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! e r " e n # ! a s s i n $

40

30

20

10

0

100

90

80

70

60

50

0061 06 02 010 002 001 0005 0002

%e&& Gra'e'

ni*rm Gra'e'

Ga+ Gra'e'

!ar#i"&e Size in mm (&*$ S"a&e)

,+en Gra'e'

Dense Gra'e'

8.Write down the factors influencing bearing capacity of foundation.

The factors are

1.Depth of foundation

2.Size of foundation

3.Shape of foundation

4.Inclination of the load5.Inclination of the foundation bed

6.Inclination of the ground

7.Ground water table

1.Write the name of test which occurs in materials lab.

Ans

• Aggregate Impact Value (AIV).

• The Flakiness Index• Elongation Index


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• Angularity Number

• Aggregate Crushing Value (ACV)

• Specific Gravity

• Loss on Heating

•Penetration

• Softening Point of Bituminous

• Materials

• Solubility of Bituminous Materials

• Flash and Fire Points

• Ductility

• CBR (California Bearing Ratio)

2.What are the laboratory testing of engineering materials.

Ans

• Consistency test of Cement

• Initial Setting Time of Cement

• Direct Compressive Strength of Cement Mortar.

• Sieve Analysis of Fine and Coarse Aggregate

• Specific Gravity and Absorption Capacity of Fine aggregate.

• Unite weight and Voids in Aggregate

• Los Angeles Abrasion test for coarse aggregate

• Compressive Strength of Cylindrical concrete Specimens and Cubes.

• Sampling and testing of Brick for Compressive Strength and

Absorption.

Draw a neat sketch of national highway.

- *a' %ay10 m

S&*+e (2.1)3 m

/erm10 m

/*rr* +i#10 m

S&*+e (2.1)3 m

/erm10 m

/*rr* +i#10 m

-*a' Mar$in-*a' Mar$in

-i$# * %ay

1 m

1 m 1 m

Se"#i*n * a#i*na& i$ay

1.What are the lab testing of Aggregates of roadway.

Ans


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o Los Angeles Abrasion test

o Aggregate Impact value

o Aggregate Crushing Value

o Soundness Test

o Gradation testo Unit weight and Void test

o Flakiness Index

o Elongation Index

o Angularity Number

2.What are the laboratory test for bituminous materials

Ans

o

Specific Gravity of Semi-Solid Bituminous Materialso Loss on Heating test

o Penetration test

o Softening Point test

o Solubility test

o Ductility test

o Flash And Fire Points test

o Spot test

o Specific Gravity test

o Distillation test

3.Define flexible and rigid pavement.

Ans

Flexible pavements: Flexible pavements will transmit wheel load stresses to

the lower layers by grain-to-grain transfer through the points of contact in

the granular structure.

Rigid Pavement: A rigid pavement typically consists of a Portland cement-

concrete slab resting on a sub-base course. The slab possesses beamlike

characteristics that allow it to span across irregularities in the underlying

material. When designed and constructed properly, rigid pavements provide

many years of service with relatively low maintenance.

4.What are the properties of aggregate for roadway. Ans


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Properties of aggregate

• Particle size and gradation

• Hardness or resistance to wear

•

Durability or resistance to weathering• Specific gravity and absorption

• Chemical stability

• Particle shape and surface texture

• Freedom from deleterious particles or substances

5.What is the Difference between Flexible & Rigid Pavement

Ans

Bangladesh Water Development Board – Sub Assistant Engineer.

1.Draw SFD and BMD for the following diagram

2.

10 kip

3 ft 3 ft 3 ft

40 kip

Flexible pavement Rigid pavement

Empirical design Precise design strength

About 20 years of age About 40 years age

More maintenance Less maintenance

Less costly Very costly

High-strength concrete Bituminous surfacing

Adopt stage constriction No stage constriction

Maintenance are less available Maintenance are more available

Surface is rough Surface is smooth

Utility location can be replaced Utility location can be due to

difficulties to break the slab

Penetration of water Almost impervious

Need street light Glare under sunlight

Environmentally not friendly Environmentally friendly

Overall life cycle is more Over all life cycle is more


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60 Kip

3060

3.Find vertical stress and total stress. Depth 8m, unit weight of saturated soil

18kn/m3, unit weight of water 9.81 KN/m3.

4.Size of beam 10”×20”. Bending moment 80 kip-ft. find maximum stress.

5.What is pH. Find OH concentration for ph value 10

6.Draw D10, D20 and D50 graph for a soil sample.7.Find FM of sand.

8.ADT = 20000. Find design hourly volume where K=0.1, D=.

9.Find discharge. Velocity of fluid 20 m/sec, dia of pipe 18 cm.

10.Design a sediment tank for 3 hours concentration period 3 hours discharge

125 liters/hour. Ratio of H: B: L = 1:1:3.

11.Estimate

12. Flow modulus of a city is given. For 25% area is 2.84, for 50% area is 3.12,

for 15% area is 15% 1.32 and for 10% area is 1.82. Find the combined flow

modulus of the city.13.Find the F AB and FBC.

1. What is the meaning of

i.FBCCI

ii.VOIP

iii.WASA

iv.ATM

v.GMT

vi.CARE

vii.SPARSO

viii.SIM

ix.MLSS

x.ICDDR

xi.RAM

xii.CAD

xiii.UNICEF

xiv.FIFA

xv.UNIFCCC

xvi.MS DOS

xvii.PVC xviii.JICA


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Documents

Factors That Influence Water Consumption