CHAPTER 1ABOUT PWD

IntroductionThe Public Works Department has a glorious history in the development of the state since pre

independence. The department is mainly entrusted with construction and maintenance of Roads,

Bridges and Govt. buildings. The department also acts as Technical Advisor to the State Government.

Initially, Irrigation, Public Health engineering were units of PWD. Subsequently these units were

given separate entities to handle increased scope of work in the respective field. Since the inception

of the Department, it has strived through its continuous quest for excellence and putting milestones in

the feat of Engineering. It is this time that the Department is treading into a new era of information

technology to keep pace with the modernization. The Public Works Department being the oldest

engineering department of the State, has its well woven network even below tensile level which

enables the P.W.D. to ensure the execution of a variety of jobs/tasks any where in the state

1.2 About Public Works Department

The Public Works Department has a glorious history in the development of the state since pre

independence. The department is mainly entrusted with construction and maintenance of Roads,

Bridges and Govt. buildings. The department also acts as Technical Advisor to the State Government

in these matters.

Total road length being maintained by the department is more than 87500 KM the Department also

maintains State buildings all over Rajasthan & outside. The current annual budget allocation to the

department for construction & maintenance activities is over Rs 1000 Crores.

The Public Works Department being the oldest engineering department of the State, has its well

woven network even below tensile level which enables the P.W.D. to ensure the execution of a

variety of jobs/tasks any where in the state.

1

Initially, Irrigation, Public Health engineering were units of PWD. Subsequently these units were

given separate entities to handle increased scope of work in the respective field. Since the inception

of the Department, it has strived through its continuous quest for excellence and putting milestones in

the feat of Engineering. It is this time that the Department is treading into a new era of information

technology to keep pace with the modernization. The Public Works Department being the oldest

engineering department of the State, has its well woven network even below tensile level which

enables the P.W.D. to ensure the execution of a variety of jobs/tasks any where in the state.

1.3 Agencies

1. Relief works in the event of Natural calamities like famine, flood, earthquakes et al.

2. D.R.D.A. Works like Employment Assurance Scheme (EAS) etc.

3. Assessments of rent of private premises requisitioned for housing Govt. offices.

4. Design, construction, maintenance and repairs of runway relating to the State Government.

5. Development and maintenance of Public Parks and Gardens in important Public Buildings.

6. Up keeping of Govt. Rest House and Circuit Houses.

7. To permit construction of approaches on both sides of roads to private individual, other

institutions, factories, Petrol Pumps etc.

8. To evacuate the encroachment coming along the road sides. To evacuate the encroachment

coming along the road sides.

2

9. Issue of certificates periodically to Cinema Houses about stability of structures/ arrangement

related to electrical fittings conforming to Cinema Regulation Act.

10. Plantation of trees along both sides of the road.

3

CHAPTER 2ABOUT THE BUILDING

2.1Introduction It project is a multi-storey residential building. This building is constructing for middle class people.

company has divided the residential buildings in different group as mentioned below-

i. HIG (HIGH INCOME GROUP) :

This group includes the flats of cost is more than 15 lac.

ii. MIG (MIDDLE INCOME GROUP) :

This group includes the flats of cost varies between 5 to 15 lac.

iii. LIG (LOW INCOME GROUP) :

This group includes the flats of cost is less than 5 lac.

This building insists In MIG (Middle Income Group).It is a four storey building (G+3).Entire

building is constructed in two combined apartments. The number of flats in each floor is four in

each apartment. Each flat consists two bed room, a living room and a kitchen (2 BHK) with

separate bathroom and toilet. The height of each floor is 3 meter. The dimensions of all flats were

same.

Dimensional detail of a flat

i. Living Room : (3.18*4.00) meter

ii. Bed Room (1) : (3.00*3.30) meter

iii. Bed Room (2) : (2.70*3.30) meter

iv. Kitchen : (1.80*2.50) meter

v. Toilet : (2.1*1.20) meter

vi. Bath Room : (1.20*1.20) meter

vii. Water Closet : (0.90*1.20) meter

Single window has provided in living room, bed rooms and kitchen .Each flat consists a balcony in

front and rear sides of apartments.

4

Fig 2.1 Frame structure building flat

2.2 Types of Building:

Building are classified on the basis of character of occupancy and type of use as –

i. Residential Building

ii. Educational Building

iii. Institutional Building

iv. Industrial Building

2.2.1 Residential Building:

In such building sleeping accommodation is provided. IT includes the living room, bed room,

kitchen, hall, and toilet and bath room. It may be a single storey building or apartments.

2.2.2 Educational Building:

These include any building using for school, college, assembly for instruction, education or

recreation.

2.2.3 Institutional Building:

These building are used for different purposes, such as medical or other treatment or care of a person

suffering from a physical or mental illnesses. These building include hospital, sanitoria, jail etc.

5

2.2.4 INDUSTRIAL BUILDING:

These are buildings in which products or material s of all kind of properties are fabricated,

assembled, processed. For example refineries, gas plant, mills etc.

6

CHAPTER 3

MATERIALS FOR CONSTRUCTION

3.1 CementThe function of cement is to combine with water and to form cement paste. This paste first sets i.e. it

becomes firms and then hardens due to chemical reaction, called hydration, between the cement and

water. On setting & hardening, the cement binds the aggregate together into a stone like hard mass &

thus provides strength, durability & water-tighten to the concrete. Quality of cement is based on

grade of cement. The grades of cement are as-

i. 33 Grades

ii. 43 Grades

iii. 53 Grades

At the site Portland cement of53grades (JK SUPER CEMENT) is used.

The cost per beg = 275rupees

The initial setting time of cement = 30 minutes (1/2 hr)

The final setting time of cement = 10 hrs.

3.2 Aggregate

Aggregates are small pieces of broken stones in irregular size and shapes.

Neat cement is very rarely used in construction works since it is liable to shrink too much and

become cracks on setting. More over, it will be costly to use neat cement in construction work.

Therefore cement is mixed with some inert strong & durable hard materials.

They also reduce the cost of concrete because they are comparative much cheaper as cement.

Types of aggregates

i. .Fine Aggregate

ii. .Coarse Aggregate

3.2.1 Fine Aggregate (Sand)

The aggregate, which pass through 4.75 mm, I.S. sieve and entirely retain on 75 micron (.075mm)

I.S. sieve is known as fine aggregate.

7

3.2.1.1 Function of Fine Aggregate

The function of using fine aggregate in a concrete mix is to fill up the voids existing in the coarse

aggregate and to obtain a dense and strong concrete with less quantity of cement and increase the

workability of the concrete mix.

3.2.2 Coarse Aggregate

The aggregate, which pass through 75 mm I.S. sieve and entirely retain on 4.75 I.S. sieve is known as

coarse aggregates. At the site the coarse aggregate was 10mm & 20mm (graded).

Fig 3.1 Aggregate

3.2.2.1 Function of Coarse Aggregate

The coarse aggregates are used in mixing of concrete. It is mixed cement, sand with water. These

aggregates increase the strength of bonding in aggregates. Coarse aggregates are used in construction

of plan cement concrete (PCC), foundation, beams and columns etc.

3.3 Grading Of Concrete

The art of doing gradation of an aggregate as determined by sieve analysis is known as grading of

aggregate. The grade of concrete is depends on size of aggregates.

8

The principle of grading is that the smaller particles will fill up the voids between large particles.

This results in the most economical use of cement paste for filling the voids & binding together the

aggregate in the preparation of concrete.

Thus proper grading of fine & coarse aggregate in concrete mix produces a dense concrete with less

quantity of cement.

3.4 Reinforcement

The material that develops a good bond with concrete in order to increase its strength is called

reinforcement. Steel bars are highly strong in tension, shear, bending moment, torsion and

compression.

3.4.1 Function of Reinforcement

Reinforcement working as a tension member because concrete is strong in compression and week in

tension so reinforcement resists the tensile stresses in the concrete members. At the site contractor

using the high strength steel bars and T.M.T. (Thermo Mechanically Treated) bars of diameter 8 mm,

10 mm, 16 mm, & 32 mm as per requirement of design.

3.5 Water It is an important ingredient of concrete because it combines with cement and forms a binding paste.

The paste thus formed fills up the voids of the sand and coarse aggregate bringing them into close

adhesion.

In this project source of water is a tube well which is closely spaced to the building. The quality of

water is good and can be used for drinking purpose also.

3.6 R.C.C.

Though plain cement concrete has high compressive strength and its tensile strength is relatively low.

Normally, the tensile strength of a concrete is about 10% to 15% of its compressive strength. Hence if

a beam is made up of plain cement concrete, it has a very low load carrying capacity since its low

tensile strength limits its overall strength. It is, there reinforced by placing steel bars in the tensile

zone of the concrete beam so that the compressive bending stress is carried by concrete and tensile

9

bending stress is carried by steel reinforcing bars. Generally in simply supported and Cantilever

beams the tension zone occurs at bottom and top of beam respectively.

10

CHAPTER 4EQUIPMENTS AND MACHINES

4.1 Batching MachineThe measurement of materials for making concrete is known as batching. The machines which used

for batching is known as batching machine.

4.2 Grinding Machine

This is a power mechanically operated machine which is used to mix the concrete. It consists a

hollow cylindrical part with inner side wings. In which cement, sand, aggregates and water is mix

properly.

Fig 4.1 Grinding machine

4.3 TransportationThe process of carrying the concrete mix from the place of it’s mixing to final position of deposition

is termed as transportation of concrete. There are many methods of transportation as mentioned

below

11

i. Transport of concrete by pans

ii. Transport of concrete by wheel barrows

iii. Transport of concrete by tipping lorries

iv. Transport of concrete by pumps

v. Transport of concrete by belt conveyors

vi. At this site belt conveyors were used.

Fig 4.2 Transportation

12

4.4 Compactors

When the concrete has been placed, it shows a very loose structure. Hence, it must be compacted to

remove the air bubbles and voids so as to make it dense and solid concrete to obtain a high strength.

There are two method- of compaction.

i. Manual compaction

ii. Mechanical compaction

Generally in large projects mechanical compactors are used . There are various mechanical

compactors which uses according to requirement as needle and screed vibrators needed to compact

the column and floor respectively.

4.5 Footing

It is part of structural transfer the load of superstructure through columns to soil strata.

i. Combined Footing

ii. Isolated Footing

iii. Raft Footing

In this project RAFT footing is provided.

4.6 StairsStairs are defined as the access to reach one floor to another floor. Stairs are designed so as it gives

maximum comfort and safety. There are several types of stairs.

i. Straight flight stairs

ii. Half turn stairs

iii. Circular stairs

iv. Spiral stairs

13

Fig4.3 Stairs

4.7 Building Drawingi. Front Elevation

ii. Ground Floor Plan

iii. Typical Floor Plan

iv. Reinforcement Detail

v. Concrete Detail

vi. Source: Site Engineer

14

CHAPTER 5BRICKMASONARY

5.1 Introduction

The bricks are obtained by moulding clay in rectangular block of uniform size and then drying and

burning these blocks. Brick masonry easy to constrctcompare stone masonry. It is less time

consuming and there is no need of skilled labour to construct it. The bricks do not require dressing

and the arty of laying bricks is so simple.

5.2 Class of BrickOn the basis of quality and performance of brick is classified in three parts-

i. CLASS A

ii. CLASS B

iii. CLASS C

At this site A class brick is used.

15

Fig 5.1 Bricks

5.3 Size and Weight Of Bricks

The bricks are prepared in various sizes. On the basis of size, BIS bricks are categories in two parts-

5.3.1 Modular Bricks:

BIS recommends a standard size of brick which is 190mm*90mm*90mm. With mortar thickness,

size of such a brick become 200mm*100mm*100mm.

5.3.2 Traditional Bricks:

The brick of which size varies and not standardized known as traditional brick.

5.4 Weight Of Brick:

It is found that the weight of 1 cubic meter brick earth is about 1800 kg. Hence the average weight of

a brick will be about 3 to 3.5 kg.

5.5 Structure of Brick

5.5.1 Stretcher

If brick lay along its length then front view of brick is known as stretcher.

5.5.2 Header

If brick laid along it’s width , then front view of brick is known as header.

5.5.3 Frog

It is top of brick. It provides strong bonding between two courses of masonry by filling the mortar. It

also consists the name of company.

5.5.4 Queen Closer

This is obtained by cutting the bricks longitudinally in two equal parts.

5.5.5 Bat

This is piece of brick, considered in relation to the length of brick as half bat, three quarter bat, etc.

16

5.6 Types Of Brick Masonry

Brick work is classified according to quality of mortar, quality of brick and thickness of joints. They

types of brick work as follows-

5.6.1 Brick Work In Mud Mortar

IN this type of brick work mud is used to fill up the joints. Mud is mixer of sand and clay. The

thickness of mortar joint is 12mm.

5.6.2 Brick Work In Lime Mortar:

In this type of brick work, lime mortar is used to fill up the joints. Lime mortar is mixer of lime and

sand the thickness of joints does not exceeds 10mm.

5.6.3 Brick Work In Cement Mortar:

In this type of brick work, cement mortar is used to fill up the joints. Cement mortar is mixer of

cement and sand in caftan ratio. The ratio Of cement and sand varies according to construction as in

brick masonry it generally kept 1:6.The thickness of joint does not exceeds 10mm. The brick work

with cement mortar provides high adopted in building construction.

At this site cement mortar is used in brick work. The ratio of Cement to sand is 1:6.

5.7 Tools Used In Brick Masonry:

The tools used in brick masonry are trowel, spirit level, plumb bob, square, hammer, straight edge.

5.7.1 Bonds In Brick Work:

There various bonds which provided in brick work to increase the stability of walls. Various types of

bonds are as follows-

i. Stretcher Bond

ii. Header Bond

iii. English Bond

iv. Flemish Bond

Stretcher Bond:

17

The bricks are laid along its length in all courses. A half and three quarter bat is used in alternative

courses to break the verticality of joints.

Fig 5.1 Stretcher

Header Bond:

The bricks are laid along its width in all courses. A half and three quarter bat is also used in

alternative courses to break the verticality of joints.

English Bond:

This bond is widely used in practice. It is consider the strongest bond. Alternate courses consist of

stretcher and header. A queen closer is put next to quoin header to break the verticality of joints.

Generally such types of bond is provided in walls width is 9 inches.

At this site ENGLISH BOND is prefer in main wall and STRETCHER BOND in partition walls.

18

Fig 5.3 English Bond

Flemish Bond:

This is also widely used because it gives better appearance to English bond. It also provides good

strength. Stretcher and header is provided in each course alternatively. A queen closer is put next to

quoin header in each alternate course to break the verticality of joints.

5.7.2 Thickness of Walls

Thickness of wall depend on load, strength of material ,length of wallet. In this project the thickness

of main wall is 9 inches and partition wall is 4.5 inches.

19

Fig 5.4 Thickness of Walls

5.8 Procedure Of Brick Masonry:

i. In frame structure brick work starts after construction of foundation, column, beam, and slabs.

Following procedure is adopt to construct the brick masonry-

ii. Initially clean and wet the surface on which brick wall is be constructed.

iii. Set a straight alignment by using threads in both side of a wall .

iv. Prepare the cement mortar.

v. At this site cement sand ratio is 1:6 for all walls.

vi. Mortar is laid on surface base and then bricks are laid over it .

vii. Prepare a course and then again laid the mortar on existing course and provides bricks in such

a way that the vertical joint should not stand in a line.

viii. To break the verticality of joints generally English or Flemish bond is adopted.

ix. Use the plumb bob to check the verticality at regular interval.

x. Also use square to check the wall is constructing straight or not.

xi. After each 1meter height of wall provide a layer of reinforced cement concrete of 1.5 to 2

inches.

xii. It will increase the strength of structure.

20

CHAPTER 6PLASTER

The term plastering is used to describe thin cover that is applied on the surface of walls. It removes

unevenness of surface of walls. Sometimes it is use for decorative purpose also.

5.1Mortar for Plastering:

Selection of type of mortar depends on various factors such as suitability of building material,

atmospheric conditions, durability etc. there are mainly three type of mortar which can be used for

the purpose of mortar

i. Lime mortar

ii. Cement mortar

iii. Water proof mortar

6.1.1 Lime Mortar

The main content of lime mortar is lime that is mixed with correct proportion of sand. Generally fat

lime is recommended for plaster work because the fat lime contains 75% of Cao and it combines with

CO2 of atmosphere and gives CaCO3 quickly. Thus, the lime sets quickly, but it imparts low

strength. So it can be used only for plaster work. The sand to be used for preparing lime mortar for

plastering work should be clean, coarse and free from any organic impurities.

6.1.2 Cement Mortar

The cement mortar consists of one part of cement to four part of clean and coarse sand by volume.

The materials are thoroughly mix in dry condition before water is added to them. The mixing of

material is done on a watertight platform. It is better than lime mortar. It is widely used in

construction work.

21

Fig 6.1 Plaster of cement mortar

6.1.3 Water Proof Mortar:

Water proof mortar is prepared by mixing one part of cement, two part of sand and pulverized alum

at the rate of 120Nperm3 of sand. In the water to be used, 0.75 of soft soap is dissolve per one liter of

water and this soap water is added to the dry mix.

6.2 Tools for Plastering

Gauging Trowel Metal Float Floating Rule

Plumb Bob Sprit Level Brushes

6.3 Method of Plastering:

According to the thickness of wall there are three method of plastering.

i. One coat method

ii. Two coat method

iii. Three coat method

6.3.1 One Coat Method

It is in the cheapest form of construction that plaster is applied in one coat.

22

This method is quietly used in rural areas for the construction of low category and cheap house.

6.3.2 Two Coat Method:

Following procedure is carried out for two coating plaster work

Clean the surface and keep it well watered on which plaster work to be done.

If it is found that the surface to be plastered is very rough and uneven, a preliminary coat is applied to

fill up the hollows before the first coat of plaster is put up on the surface.

Now the first coat is applied on the surface. The usual thickness of first coat for brick masonry is

9mm to10mm.

Second coat of plaster is applied after about 6 hours and the thickness of second caot is usually about

2mm to 3mm.It is finished as per requirement.

6.3.3 Three Coat Method:

The procedure for plaster in three coats is the same as above except that the num of coats of plaster is

three.

Table:

Name of coat Thicknessa

First coat Rendering coat 9 to 10 mm

Second coat Floating coat 6 to 9 mm

Third coat Finishing coat 3 mm

23

CHAPTER 7EVALUATING MUNICIPAL WATER DISTRIBUTION SYSTEMS

7.1 Primary Considerations

This topic has two primary objectives: The first is to understand the evaluation of an installed

municipal water supply delivery system by identifying all the physical components of any specific

water distribution system. The same basic concepts and principles apply to small community water

systems and large city water systems. For a basic understanding of these concepts, two illustrations

are provided that include a relatively small water distribution system and a medium size water

distribution system. These concepts will cover 92 percent of all the water supply systems in the

United States. While there are similarities to all water systems, it should be recognized that the

likelihood of two water systems being exactly alike in physical features is remote because the raw

water sources in relation to the water delivery demands can hardly be the same.

The second objective is to provide recognized practices for conducting water supply tests at

prescribed intervals to measure the water system delivery capability and ensure that the system is

meeting the water supply demand. An important part of this second objective is to use the results of

water supply tests to monitor the performance of the water delivery system in relation to the existing

water supply and the constant changes in demand on the water system. The following material will

illustrate the broad features of water supply systems in order to understand how this can be

accomplished. Chapter 2 presents a basic understanding of hydraulic fundamentals needed to

accomplish water supply testing and evaluation accurately, and Chapter 3 presents water supply

system evaluation methods for determining existing water supplies for consumer consumption and

especially for fire protection

7.2 Functional Components of a Water Utility System

A water utility system can be relatively simple for a community of 3,000 to 5,000. At this level of

population, communities often are served by wells. The well water is treated typically by chlorination

and then either pumped directly into water distribution mains to supply customers or pumped into

ground-level or elevated storage tanks where the water flows by gravity on demand to each customer

24

on the water system. Some fire hydrants may be located on the distribution system to provide a

minimum fire flow capability in the range of 250 gallons per minute (gpm) to 500 gpm. Figure 7-

1illustrates an actual example of a community that has these characteristics.

Fig 7.1 Water Utility System

As the population served in the illustration of a small community increases, so does the complexity of

the water delivery system. Figure7-2depicts the functional components expected to be in place in

communities with populations ranging from 25,000 to 50,000. This is fairly typical of what one needs

to understand in evaluating water supply systems to assure that rates of water can be delivered

through the distribution system to simultaneously meet consumer consumption demands and meet

25

Needed Fire Flow (NFF) criteria for structural fire suppression. Therefore, before specifically

examining and tracing the water system component diagramed in Figure 7-2, it is essential that each

component be evaluated in relationship to the capability of the water delivery system, plus the

function of selected components of the water system to meet the needed domestic and fire protection

demands on the system. This needs to be assessed for each and every water system as a function of

rates of water usage. Three historical or predicted water demand rates are involved in the discussion

of consumer demand and fire protection:

Average daily demand–the average of the total amount of water used each day during a 1-year

(designed) period.

Maximum daily demand–the maximum total amount of water used during any 24-hour period. The

Insurance Services Office. Inc. (ISO) bases this calculation on the highest demand during the

previous 3 years from the years of an ISO Grading Schedule evaluation. Note: This number should

consider and exclude any unusual and excessive uses of water that would affect the calculation i.e., a

broken water main.

Maximum hourly demand–the maximum amount of water used in any single hour of any day in a

3-year period. It normally is expressed in gallons per day by multiplying the actual peak hour by 24.

Fig 7.2 Maximum hourly demand

26

When specific data on past consumption levels are not available, a good rule of thumb is that

maximum daily demand may vary from 1.5 to 3.0 times the average daily demand, while the peak

hourly rate may vary from 2 to 8 times the average daily rate. In small water systems, peaking factors

may vary significantly higher.

Design flow and analysis should be based on the maximum hourly demand or the maximum daily

demand plus the fire flow requirement, whichever is greater. This distribution system should be

designed to maintain a minimum pressure of 20 pounds per square inch (psi) at all water taps

including fire hydrant locations under all conditions of design flow.

[This is a recommended practice of the American Water Works Association (AWWA) Manual of

Water Supplies Practices–M-31 and M-17 along with criteria published by the ISO in accordance

with Grading Schedule evaluations.]

In order to account for system demands, chart recorders should be in place at every separate location

where purified water enters the distribution system, including finished water holding basins, direct

pumping facilities, finished water standpipe tanks, and finished water gravity tanks. This is the only

reasonably accurate way to monitor water system demand on an hourly, or less frequent, time period,

24 hours a day, 365 days a year. This is a key consideration in matching water system demand to

water system availability.

7.3Tracing the Components of an Urban Water Distribution System

The following information is presented in the context of Figure 7-2.

1. Raw water source shown in the upper left of the drawing marked.

The water source may be a lake, a river, a reservoir, a well field, or, more recently, salt water sources

which can be purified through new techniques in water filtration and reverse osmosis. The Tampa,

Florida, municipal water system now has the capability of producing 60 percent of the city’s water

demand using salt water. The AWWA recommended guideline on raw water capability is that the

supply source(s) have a sufficient capacity at all time to meet maximum daily demand for a

continuous period of 5 days. (Reference 1, pg. 12) This is demonstrated on the drawing by a raw

water storage pond marked 2.

27

Water Department action needed: A depth gauge is needed on each raw water source. A hydrologist

or geologist needs to asses the gallons of water in storage at gauge level. There typically is not an

equal drop or increase as water is drawn off or is supplemented by rain and runoff, due to the slope of

the container sides and the slope of the bottom of the holding basin. This monitoring needs to be done

daily if a diminishing supply is observed, to predict long-term supply conditions.

2. Typical raw water pumping facility marked

In the case of the illustrated water system, the pumping facility has a dual purpose. First it can pump

the raw water, which is filtered by trash racks (coarse screws) and other finer screening, if necessary,

to the treatment facility where the water is processed to meet Environment Protection Agency (EPA)

criteria and even more rigid requirements for water treatment in several States through State health

departments. Second, there needs to be the capability to transfer water to and from the raw water

storage facility. This builds reliability into the water system. Constant-recording flow meters are

needed on each of the pumps in this facility to assess how and when water is being transported

through facility and the rate of water in gpm.

Water Department action needed: The secondary raw water storage facility is important for retaining

a reserve supply of water in case of a major pipe failure on the distribution piping, or if the main

source of water become depleted due to drought conditions or contamination of the primary supply.

3. The treatment facility marked.

Chapter 7 covers the basic of water supply treatment and the sampling of water required to meet EPA

criteria. There is a need to know the maximum water processing rate and the length of time that water

can be processed at this rate, because this could limit water delivery to the distribution piping system.

Process flow rates need to be monitored on a continuous timeline, which also will account for the

downtime in the treatment plant to flush and clean equipment.

Note in the illustration that a finished waterfacility is provided on the delivery side of the treatment

plant; this is commonly called a clear well. In gravity feed systems, water flows from the clear well(s)

into the distribution piping, or it is pumped where the land surface is relatively level. Water levels in

the clear well(s) needed to be monitored closely on a daily basis with data recorded hour.

28

4. A high service pumping station marked.

Note that this pumping station is located on the water distribution delivery side of the water treatment

plant. High-level service pumps may be needed to:

a. Pump water up to service areas that have higher elevations than other areas of a community.

b. Fill gravity tanks that float on the water supply distribution system.

c. When service pumping stations are used to distribute water, and no water storage is provided, the

pumps force water directly into the water mains. From a water system evaluation perspective, there is

no outlet for the water except as it furnishes consumer consumption for actual fire flows. Variable

speed pumps or multiple pumps may be required to provide adequate water delivery service because

of fluctuating demands. The efficiency and expense of this pumping equipment needs to be

considered carefully. For example, it is a disadvantage that the peak power demand of the water plant

is likely to occur during periods of high electrical consumption, and thus increase power costs.

Furthermore, systems with little or no storage should be provided with standby electrical generating

capability or pumps driven directly by internal combustion engines. These standby generators and

engines needs to be tested routinely (e.g., several hours per week).

5. A gravity storage facility marked.

An extremely important element in a water distribution system is water storage. (Reference #3, pg.

12) System storage facilities have a far-reaching effect on a system’s ability to provide adequate

consumer consumption during periods of high demand while meeting fire protection requirements.

The two common storage methods are ground-level storage and elevated storage. The finished water

storage at number 4 on Figure 1-2 is an example of ground-level storage; this type of storage also

may be contained in covered tanks. Emphasis is put on elevated storage as a stand-alone in Chapter 7

of this Manual.

7. Water entering the distribution system marked.

There are two basic types of pipe layout for delivering water to consumer taps and to supply water to

individual fire hydrants. The preferred method is to loop the entire service area with a primary feeder

main; the size is determined by hydraulic analysis. Interior to the ring main are cross-connected

secondary feeders provided along the major streets in the community. Interior water mains that

essentially provide water to residential areas are cross-connected to the secondary feeders. The

29

advantages of this type of pipe system layout are two fold: 1) the water to every service location or

demand point is supplied from two directions, which is considered to be the most efficient hydraulic

design to minimize pipe sizes; and 2) in the event that a pipe section is out of service for cleaning,

breakage from an accident, tapping for service extension, or whatever reason, water can be supplied

to any demand point from a different travel path. In older community water systems single primary

feeder supplies secondary feeders and distributor pipes along block fronts in a branched layout

configuration where at any demand point water is supplied from one direction only. This arrangement

decreases the reliability of a water system significantly and has a tendency to decrease fire flow

capability for larger scale fires. The capability of water main systems for meeting fire flow criteria

can be determined only by semiannual fire flow tests as presented below.

7.4Evaluating Distribution System Appurtenances

1. Piping and valve arrangement.

A piping system serving the consumers in a small community is illustrated in Figure 7-3. The primary

feeders, sometimes called arterial mains, form the skeleton of the distribution system. They are

located so that large quantities of water can be carried from the pumping plant to and from the

storage tanks and the distribution system.

Primary feeders should be arranged in several interlocking loops, with the mains not more than 3,000

feet apart. Looping allows continuous service as previously identified through the rest of the primary

mains, even when one portion is shut down temporarily for repairs. Under normal conditions, looping

also allows supply from two directions for large fire flows. Large feeders and long feeders should be

equipped with blow-off valvesat low points and air relief valvesat high points. Valves should be

placed so that a pipe break will affect water service onlyin the immediate area of the break.

The secondary feeders carry large quantities of water from the primary feeders to points in the system

in order to provide for normal domestic consumption supply and fire suppression. They form smaller

loops within the loops of the primary mains by running from one primary feeder to another.

Secondary feeders should be spaced only about three blocks apart, or a maximum of 1,500 feet. This

spacing allows concentration of large amounts of water for firefighting without excessive head loss

and resulting low pressure.

30

Small distribution mains (i.e., distributors) are to form a grid over the area to be served. They supply

water to residential taps and fire hydrants along residential block fronts throughout areas with this

occupancy classification. In no case should the pipe size be less than 6 inches in diameter. Larger size

pipes may be needed in residential areas for multiple occupancy buildings. In this case, pipe sizing is

based on the sum of the peak day water use plus fire-flow requirements. Where there are multiple-

occupancy buildings of more than one floor, required pipe sizing is almost always controlled by the

fire-flow requirement.

Water distribution piping should be sized and spaced to meet design flow. The minimum size water

main for providing fire protection and serving fire hydrants is 6 inches in diameter. Typical values for

distribution system piping are summarized in Table 1-2.

All areas served by a water distribution system should have fire hydrants installed in locations and

with spacing for fire department use. The following method of locating fire hydrants should be

observed in the United States. This method is outlined in Section 614 of the the ISO Fire Suppression

Rating Schedule–2003 edition. (Reference #9, pg. 12) [Sidebar: Canada uses an area method.]

Briefly summarized, the procedure examines a representative fire-risk location and a computed NFF

at that location. The first determination is that a recognized fire hydrant be within 1,000 feet of the

fire risk, as fire hose is laid from the fire hydrant to the fire risk. A recognized fire hydrant on a

municipal water system must flow a minimum of 250 gpm at 20 psi residual pressure for 2 hours.

The actual flow capability from each fire hydrant in the vicinity of the fire risk is limited by the

distance to the fire risk as follows: (Reference #9, pg. 12)

Credit is awarded up to 1,000 gpm from each hydrant within 300 feet of the fire-risk building; 670

gpm from hydrants within 301 to 600 feet of the fire-risk building; and 250 gpm from hydrants

within 601 to 1,000 feet of the fire-risk building.

Furthermore, the water utility should review hydrant spacing or representative fire risks in the

community with the responsible first-due fire company because the supply hose capacity on fire

apparatus may limit the credit assigned by ISO to this item in the Fire Suppression Rating Schedule.

The pipe connecting the fire hydrant to the water main is call the hydrant branch or lateral. Every

lateral needs to have an installed valve to enable the water utility to isolate the fire hydrant for repair

or general maintenance.

31

In addition, fire department use typically requires a maximum lineal distance between fire hydrants

along street fronts in commercial and congested built-up areas of 300 feet, and 600 feet for light

single-family residential areas. Good practice calls for fire hydrants at intersections, in the middle of

a block where the NFF equals or exceeds 1,200 gpm, and at the end of dead-end streets

7.5Summary Statement on Water Supply Distribution

Water supply distribution systems are rather straightforward to evaluate in small communities with a

population range up 5,000. The proper evaluation of water supplies and distribution for larger

communities, up to cities over 100,000 population, is no simple thing. Water system maps that are

kept current and electronic graph records for all of the water supply that enters the distribution system

are essential to establish an understanding of actual supply versus consumption on an hourly basis,

daily basis, monthly basis, and yearly basis. If this information is not in place, the first step to the

evaluation of a water system is to put in place a records management system, and then to pay close

attention to this system. The water utility has the responsibility to keep public officials, especially fire

officials, apprised of the current conditions of the water system. This topic paints the big picturefor

developing and maintaining a comprehensive evaluation of a water system.

32

CHAPTER 8RAIN WATER HARVESTING SYSTEM

8.1 Rainwater Harvesting

Rainwater harvesting is a technology used to collect, convey and store rain for later use from

relatively clean surfaces such as a roof, land surface or rock catchment. The water is generally stored

in a rainwater tank or directed to recharge groundwater. Rainwater infiltration is another aspect of

rainwater harvesting playing an important role in storm water management and in the replenishment

of the groundwater levels. Rainwater harvesting has been practiced for over 4,000 years throughout

the world, acticed for over 4,000 years throughout the world, traditionally in arid and semi-arid areas,

and has provided drinking water, domestic water and water for livestock and small irrigation. Today,

rainwater harvesting has gained much on significance as a modern, water-saving and simple

technology.

The practice of collecting rainwater from rainfall events can be classified into two broad categories:

land-based and roof-based. Land-based rainwater harvesting occurs when runoff from land surfaces is

collected in furrow dikes, ponds, tanks and reservoirs. Roof-based rainwater harvesting refers to

collecting rainwater runoff from roof surfaces which usually provides a much cleaner source of water

that can be also used for drinking.

Fig.8.1 Small-scale rainwater harvesting systems and uses

33

Rooftop rainwater harvesting at the household level is most commonly used for domestic purposes. It

is popular as a household option as the water source is close

to people and thus requires a minimum of energy to collect it. An added advantage is that users own,

maintain and control their system without the need to rely on other community members.

8.2 Requirement rainwater harvesting

In many regions of the world, clean drinking water is not always available and this is only possible

with tremendous investment costs and expenditure. Rainwater is a free source and relatively clean

and with proper treatment it can be even used as a potable water source. Rainwater harvesting saves

high-quality drinking water sources and relieves the pressure on sewers and the environment by

mitigating floods, soil erosions and replenishing groundwater levels. In addition, rainwater harvesting

reduces the potable water consumption and consequently, the volume of generated wastewater.

Application areas

Rainwater harvesting systems can be installed in both new and existing buildings and harvested

rainwater used for different applications that do not require drinking water quality such as toilet

flushing, garden watering, irrigation, cleaning and laundry washing. Harvested rainwater is also used

in many parts of the world as a drinking water source. As rainwater is very soft there is also less

consumption of washing and cleaning powder. With rainwater harvesting, the savings in potable

water could amount up to 50% of the total household consumption.

8.3Criteria for selection of rainwater harvesting technologies

Several factors should be considered when selecting rainwater harvesting systems for domestic use:

i. type and size of catchment area

ii. local rainfall data and weather patterns

iii. family size

iv. length of the drought period

v. alternative water sources

vi. cost of the rainwater harvesting system.

When rainwater harvesting is mainly considered for irrigation, several factors should be taken into

consideration. These include:

34

i. rainfall amounts, intensities, and evapo-transpiration rates

ii. soil infiltration rate, water holding capacity, fertility and depth of soil

iii. crop characteristics such as water requirement and length of growing period

iv. hydrogeology of the site

v. socio-economic factors such as population density, labour, costs of materials and regulations

governing water resources use.

8.4Components of a rooftop rainwater harvesting system

Although rainwater can be harvested from many surfaces, rooftop harvesting systems are most

commonly used as the quality of harvested rainwater is usually clean following proper installation

and maintenance. The effective roof area and the material used in constructing the roof largely

influence the efficiency of collection and the water quality.

Rainwater harvesting systems generally consist of four basic elements:

i. A collection (catchment) area

ii. A conveyance system consisting of pipes and gutters

iii. A storage facility, and

iv. A delivery system consisting of a tap or pump.

Fig. 8.2: A schematic diagram of a rooftop rainwater harvesting system.

35

(1) A collection or catchment system is generally a simple structure such as roofs and/or gutters that

direct rainwater into the storage facility. Roofs are ideal as catchment areas as they easily collect

large volumes of rainwater.

The amount and quality of rainwater collected from a catchment area depends upon the rain intensity,

roof surface area, type of roofing material and the surrounding environment. Roofs should be

constructed of chemically inert materials such as wood, plastic, aluminium, or fibreglass. Roofing

materials that are well suited include slates, clay tiles and concrete tiles. Galvanised corrugated iron

and thatched roofs made from palm leaves are also suitable. Generally, unpainted and uncoated

surface areas are most suitable. If paint is used, it should be non-toxic (no lead-based paints).

(2) A conveyance system is required to transfer the rainwater from the roof catchment area to the

storage system by connecting roof drains (drain pipes) and piping from the roof top to one or more

downspouts that transport the rainwater

through a filter system to the storage tanks. Materials suitable for the pipework include polyethylene

(PE), polypropylene (PP) or stainless steel.

Before water is stored in a storage tank or cistern, and prior to use, it should be filtered to remove

particles and debris. The choice of the filtering system depends on the construction conditions. Low-

maintenance filters with a good filter output and high water flow should be preferred. “First flush”

systems which filter out the first rain and diverts it away from the storage tank should be also

installed. This will remove the contaminants in rainwater which are highest in the first rain shower.

(3) Storage tank or cistern to store harvested rainwater for use when needed. Depending on the

space available these tanks can be constructed above grade, partly underground, or below grade. They

may be constructed as part of the building, or may be built as a separate unit located some distance

away from the building.

The storage tank should be also constructed of an inert material such as reinforced concrete,

ferrocement (reinforced steel and concrete), fibreglass, polyethylene, or stainless steel, or they could

be made of wood, metal, or earth. The choice of material depends on local availability and

36

affordability. Various types can be used including cylindrical ferrocement tanks, mortar jars (large jar

shaped vessels constructed from wire reinforced mortar) and single and battery (interconnected)

tanks. Polyethylene tanks are the most common and easiest to clean and connect to the piping system.

Storage tanks must be opaque to inhibit algal growth and should be located near to the supply and

demand points to reduce the distance water is conveyed.

Water flow into the storage tank or cistern is also decisive for the quality of the cistern water. Calm

rainwater inlet will prevent the stirring up of the sediment. Upon leaving the cistern, the stored water

is extracted from the cleanest part of the tank, just below the surface of the water, using a floating

extraction filter. A sloping overflow trap is necessary to drain away any floating matter and to protect

from sewer gases. Storage tanks should be also kept closed to prevent the entry of insects and other

animals.

(4) Delivery system which delivers rainwater and it usually includes a small pump, a pressure tank

and a tap, if delivery by means of simple gravity on site is not feasible.

Disinfection of the harvested rainwater, which includes filtration and/or ozone or UV disinfection, is

necessary if rainwater is to be used as a potable water source.

8.5Designing a rainwater harvesting system

For the design of a rainwater harvesting system, rainfall data is required preferably for a period of at

least 10 years. The more reliable and specific the data is for the location, the better the design will be.

Data for a given area can be obtained at the meteorological departments, agricultural and

hydrological research centres and airports.

One simple method of determining the required storage volume, and consequently the size of the

storage tank, is shown below:

With an estimated water consumption of 20 l/c*d, which is the commonly accepted minimum, the

water demand will be = 20 x n x 365 l/year, where n=number of people in the household. If there are

five people in the household then the annual water demand is 36,500 litres or about 3,000 l/month.

For a dry period of four months, the required minimum storage capacity would be about 12,000 litres.

As rainwater supply depends on the annual rainfall, roof surface and the runoff coefficient, the

amount of rainwater that can be collected = rainfall (mm/year) x area (m2) x runoff coefficient.

37

As an example: a metal sheet roof of 80 m2 with 800 mm rainfall/year will yield = 80 x 800 x 0.8 =

51,200 l/year.

Figure 3 demonstrates the cumulative roof runoff (m3) over a one-year period and the cumulative

water demand (m3). The greatest distance between these two lines gives the required storage volume

(m3) to minimise the loss of rainwater.

Fig. 3: Graphical method to determine the required storage volume for a rainwater cistern

8.7 Types of rainwater use

Rainwater systems can be classified according to their reliability, yielding four types of user regimes:

• Occasional - water is stored for only a few days in a small container. This is suitable when there is a

uniform rainfall pattern with very few days without rain and when a reliable alternative water source

is available.

• Intermittent - in situations with one long rainy season when all water demands are met by rainwater.

During the dry season, water is collected from other sources.

• Partial - rainwater is used throughout the year but the 'harvest' is not sufficient for all domestic

demands. For example, rainwater is used for drinking and cooking, while for other domestic uses

(e.g. bathing and laundry) water from other sources is used.

• Full - for the whole year, all water for all domestic purposes comes from rainwater. In such cases,

there is usually no alternative water source other than rainwater, and the available water should be

well managed, with enough storage to bridge the dry period.

38

Which of the user regimes to be followed depends on many variables including rainfall quantity and

pattern, available surface area and storage capacity, daily consumption rate, number of users, cost and

affordability, and the presence of alternative water sources.

8.7Benefits of rainwater harvesting

Rainwater harvesting in urban and rural areas offers several benefits including provision of

supplemental water, increasing soil moisture levels for urban greenery, increasing the groundwater

table via artificial recharge, mitigating urban flooding and improving the quality of groundwater. In

homes and buildings, collected rainwater can be used for irrigation, toilet flushing and laundry. With

proper filtration and treatment, harvested rainwater can also be used for showering, bathing, or

drinking. The major benefits of rainwater harvesting are summarised below:

i. rainwater is a relatively clean and free source of water

ii. rainwater harvesting provides a source of water at the point where it is needed

iii. it is owner-operated and managed

iv. it is socially acceptable and environmentally responsible

v. it promotes self-sufficiency and conserves water resources

vi. rainwater is friendly to landscape plants and gardens

vii. it reduces stormwater runoff and non-point source pollution

viii. it uses simple, flexible technologies that are easy to maintain

ix. offers potential cost savings especially with rising water costs

x. provides safe water for human consumption after proper treatment

xi. low running costs

xii. construction, operation and maintenance are not labour-intensive.

Disadvantages

The main disadvantages of rainwater harvesting technologies are the limited supply and uncertainty

of rainfall. Rainwater is not a reliable water source in times of dry periods or prolonged drought.

Other disadvantages include:

i. low storage capacity which will limit rainwater harvesting, whereas, increasing the storage capacity

will add to the construction and operating costs making the technology less economically feasible

39

ii. possible contamination of the rainwater with animal wastes and organic matter which may result in

health risks if rainwater is not treated prior to consumption as a drinking water source

iii. leakage from cisterns can cause the deterioration of load-bearing slopes

iv. cisterns and storage tanks can be unsafe for small children if proper access protection is not

provided.

Maintenance

Maintenance is generally limited to the annual cleaning of the tank and regular inspection and

cleaning of gutters and down-pipes. Maintenance typically consists of the removal of dirt, leaves and

other accumulated material. Cleaning should take place annually before the start of the major rainfall

season. Filters in the inlet should be inspected every about three months. Cracks in storage tanks can

create major problems and should be repaired immediately.

Costs

The associated costs of a rainwater harvesting system are for installation, operation and maintenance.

Of the costs for installation, the storage tank represents the largest investment which can vary

between 30 and 45% of the total cost of the system dependent on system size. A pump, a pressure

controller and fittings in addition to plumber’s labour represent other major costs of the investment.

In general, a rainwater harvesting system designed as an integrated element of a new construction

project is more cost-effective than retrofitting a system. This can be explained by the fact that many

of the shared costs (such as for roofs and gutters) can be designed to optimise system performance

and the investment can be spread over time.

8.8Rainwater quality standards

The quality of rainwater used for domestic supply is of vital importance because, in most cases, it is

used for drinking. Rainwater does not always meet drinking water standards especially with respect

to bacteriological water quality. However, just because water quality does not meet some arbitrary

national or international standards, it does not automatically mean that the water is harmful to drink.

Compared with most unprotected traditional water resources, drinking rainwater from well-

maintained roof catchments is usually safe, even if it is untreated. The official policy of the

Australian Government towards the question “Is rainwater safe to drink?” is as follows: “Providing

40

the rainwater is clear, has little taste or smell and is from a well-maintained system, it is probably safe

and unlikely to cause any illness for most users”. For immuno-compromised persons, however, it is

recommended that rainwater is disinfected through boiling prior to consumption.

Drinking water from rainwater

In many countries of the world where water resources are not available at a sufficient quality fit for

human consumption, rainwater acts as a substitute for drinking water and other domestic uses. In

some remote islands around the globe, rainwater may even act as the major potable water source for

their population.

The most important issue in collecting rainwater is keeping it free of dirt such as leaves, bird

droppings and dead animals, and avoiding contamination with pollutants like heavy metals and dust.

Rainwater can be also treated for use as a potable water source. The use of slow sand filtration has

proved to be a simple and effective treatment technology for the elimination of most of the organic

and inorganic pollutants that may be present in rainwater, as well as producing a virtually pathogen-

free water for drinking.

41

CONCLUSION

As per my training report I have conclude that , during 45 days. I am familiar with the construction

of brick masonry & plastering and study of water distribution & rain water harvesting system under

a Center Public Work Department project. Brick masonry is provided to transfer the load of structure

to foundation. All though maximum load of building comes on columns and beams. Plaster is

necessary to cover and protect the masonry from weathering factor. It is a layer of cement mortar of

thickness is 1 to 1.5 inches. The basic knowledge of rainwater harvesting system also important for

future water saving planning. I am very thankful to all those people who help me to get knowledge of

brick masonry and plastering & RWHS.

42

Chapter 10Learning and outcome

1. Learning how to work in professional environment.

2. Learning the technology

3. Punctuality,time evaluation,priority deciding

4. Helped in developing knowledege about the technology

5. Overcoming hurdles and meeting hurdles

6. Implementation of theoritical knowledge in practical.

7. I built my knowledge about the Building construction .

43