CPWD Report on Construction of Police Station

KRISHNA INSTITUTE OF ENGINEERING
&TECHNOLOGY

Ghaziabad

CENTRAL PUBLIC WORKS DEPARTMENT
New Delhi

PROJECT REPORT

ON

Construction site of POLICE STATION

AT

CENTRAL PUBLIC WORKS DEPARTMENT

(CPWD)

(TRAINING PERIOD: 15 JUNE - 31JULY)

SUBMITTED BY:-

ALOKMISHRA

0902900015
(CE-3RD YEAR)

KRISHNA INSTITUE OF ENGINEERING & TECHNOLOGY, GHAZIABAD

GUIDED BY:-

Er. P R CHARAN BABU
EXECUTIVE ENGINEER

Central Public Works Department, I P Bhawan,New Delhi Page 2

ACKNOWLEDGEMENT

It is indeed a great pleasure and privilege to present this report on training at CPWD.

I am extremely grateful to my training and placement officer for issuing a Training
letter, whichmade my training possible at CPWD,Delhi.

I would like to express my gratitude to Er P R CHARAN BABU for his invaluable
suggestions, motivation,guidance and support through out the training.His
methodology to start from simple ant then deepen through made me to bring out
this project report without anxiety.

Thanks to all other CPWDofficials, operators and all other members of CPWD, yet
uncounted for their help in completing the project and see the light of success.

I am very thankful to friends, colleagues and all other persons who rendered their
assistance directly or indirectly to complete this project work successfully.

I extended my due thanks to Er. VINOD who gave mevaluable time and suggestions andg
uide me a lot at various stages of my Summer Training.

Dated- July 2012ALOK MISHRA


INDEX

S.NO DESCRIPTION

1. INTRODUCTION

2. PROJECT OVERVIEW

3. SITE LOCATION

4. FORMWORK

5. PLANNING

6. SEQUENCE OF STRUCTURE WORK

7. PROJECT MONITORING

8. QUALITY

9. CONCLUSION


1.INTRODUCTION
ABOUT

The Central Public Works Department of India is a Central Government owned authority that
is in charge of public sector works in the country. Central Public Works Department (CPWD)
under Ministry of Urban Development is entrusted with construction and maintenance of
buildings for most of the Central Government Departments, Public undertakings and
autonomous bodies.

In the Indian History both pre and post independence - CPWD has a glorious era of more than 150 year
with dedicated, energetic and committed corps of Engineers and Architects. Before being re-structured to
its present form in 1930 “Central Public Works Department” originated in July 1854 when the Governor
General of India decided to set up a Central Agency:

“to exercise universal control over public works in India with best of scientific knowledge with
authority & system”.

Central Public Works Department, Delhi is the premier agency of Govt. of India engaged in
planning, designing, construction and maintenance of Government assets in the field of built
environment and infrastructure development. Assets in built environment include Hospitals,
Schools, Colleges, Technical Institutes, Police Buildings, Prisons, Courtsetc; assets in
infrastructure development include Roads, Bridges, Flyovers, Footpaths, Subways etc.

CPWD Delhi also sustains and preserves these assets through a well developed system of
maintenance which includes amongst others specialized services like rehabilitation works, roads
signage and aesthetic treatments like interiors, monument lighting, landscaping.

MISSION

1. Sound Planning and Design

2. Engineered Construction

3. Effective Maintenance

4. Benchmarking the Standards

5. Capacity Building

6. Public Private Partnership

7. Manpower Planning

8. Transparency in Management

1.Sound Planning and Design


1. All building norms and specifications to be standardized.

2. Architectural and structural design to be undertaken in-house as far as possible.

3. Detailed planning of all services to make the buildings operational in all respects.

4. Architectural and structural designs to be coordinated to evolve an

efficient building system compliant with latest Indian Standards.

2.Engineered Construction

1. Standardization of different building elements including their

pre-fabrication, mechanization in construction, use of

innovative materials and technologies adopting clean development

mechanism resulting in conservation of energy and natural resources.

3.Effective Maintenance


1. To preserve and maintain buildings and services in good operating condition.

2. To improve the specifications depending upon the development that is

taking place in the built environment.

4.Benchmarking the Standards

1.Updation of Specifications and standards for public works including

Delhi Schedule of Rates, Analysis of Rates, Works and Maintenance

Manual on regular basis.

5.Capacity Building

1. Updatingtechnical knowledge of engineers, architects by effective

training and participation in seminars, workshops etc.

2. Effective training to develop managerial skills and handling public

grievances so that engineers, architects and horticulturists become

development managers for tomorrow.

3. Target oriented training to workers on contemporary skills and behavioural


science to improve service delivery mechanism.

6.Public Private Partnership

1. To undertake contract or concession agreement with private sector

company for delivering General Pool Residential Accommodation

and General Pool Office Accommodation on payment of user charges

to:-

(1) Increase the stock of dwelling units thereby providing housing

to government employees.

(2) Increase the office space thereby providing comfortable working environment

to government employees

7.Manpower Planning

1. To provide the manpower of CPWD with professional environment,

excellent working opportunities and state of art technology.

2. To provide performance and ability based approach to career development as per

policy of the Government.


8.Transparency in Management of Works

1. e- tendering shall be introduced.

2. Effective use of websites in discharge of regulatory, enforcement and the

functions shall be introduced through integrated computerization.

3. Web based work progress monitoring system shall be introduced.


CENTRAL DESIGN ORGANISATION (CDO)

CDO was created in the year 1969 with a view to provide higher level of design inputs in

multi-storeyed projects which could not be handled by the design units under Chief

Engineers. As pressures on availability of land increased, CPWD could utilize the services

of CDO for high rise built habitats and complex projects such as jetties and bridges. CDO

has provided its services to over 350 projects in CPWD and 35 projects in last four years

alone. Important projects designed by CDO are Parliament Library Complex, Parliament

Annexe Building, National Gallery of Modern Art, National Museum, Supreme Court

Extension, National Stadium, and Afghan Parliament in Kabul, Lal Bahadur Shastri

National Academy of Administration Mussoorie, and Hall of States ITPO etc.

At present, Central Designs Organisation has the responsibility of structural design of

complex structures (with structural cost over Rs. 25 Crores) incorporating state of art

engineering practices and technology. It is also responsible for contributing to the

consultation process of BIS for framing new Codes and handbooks and thus setting

standards for the Construction Industry as a whole. CDO also offers its services in

preparing several technical documents/reports such as Handbook on Seismic Retrofitting,

Design Manuals, Fly ash utilization guidelines, and seismic assessment reports of critical

government buildings. CDO also develops computer aided design and planning software

such as Integrated Analysis & Design of Buildings (IADB).Important projects being

designed in CDO at present are Extension to Parliament Annexe Building, Indira


ParyavaranBhawan, New Campus for Supreme Court, NWAI Jetty at Kolkata and Guwahati,

Underground Parking for NirmanBhawan, and AG Office Building Lucknow.

CDO is headed by the Chief Engineer (Designs) who is responsible for the overall

administrative and technical control of the unit. Four Superintending Engineers directly

report to the C.E (Designs). S.Es are the direction officers for control, coordination and

execution of all tasks related to modelling analysis, design, detailing and drafting of

structural drawings. Out of four Superintending Engineers, one is in-charge of Computer

Cell CPWD responsible for e-Governance in the department. Each SE has three Executive

Engineer (Designs) reporting to him, who is responsible for all modelling, design and

drafting tasks and preparing design proposals. Each EE is assisted by a small team of Asst

Executive Engineers/ Asst Engineers, Junior Engineers and Draughtsmen. CDO is manned

by civil engineers having experience in structural design.

All design and drafting work in CDO is fully computerised. Design and analysis is done by

using softwares such as STAAD, eTABS, STRUDS, SAP, STAADFoundation etc. Drafting

work is done through AUTOCAD using heavy duty full size HP drafter plotters. Computing

is done through high end Intel Core i7 – 2600 Processors.


Computer Cell, CDO

The CPWD is determined to use IT to usher in era of e-Gov to simplify processes, bringing

in transparency, accountability, efficiency; effectiveness and need based timely and quality

information to all its stakeholders, and to use the available resources more effectively.

The CDO unit of CPWD has been entrusted this job. Many steps towards e-Gov initiatives

have already been taken e.g. PIMS for HR management, including training module and

monitoring of PG and VIP references; web based project monitoring system for monitoring

physical and financial progress of the projects, access to client to view the progress of the

projects and also to furnish the remarks;

CPWDSEWA in Delhi & NCR and being extended for PAN India for maintenance related

complaints management; enlistment for class one contractors; and CPWD website for

publishing all circulars and OMs and other information.

2. PROJECT OVERVIEW


NAME of WORK:Construction of Police Station KhajuriKhas, Near Sonia Vihar,
Delhi (SH: C/o Police Station Building, Electric sub Station & External
Development Work i.e. Internal Electrical Installations)

AGREEMENT NO. : 03/EE/CD-III/2011-12

NAME OF CONTRACTOR: M/S ROSHAN REAL ESTATES PVT LTD.

PLOT SIZE:5984Sqm. Area

ESTIMATED COST: Civil Work- Rs 6, 01, 47,287/-
Elec. Work- Rs 24, 75,332/-
Rs 6, 26, 22,609/-

TENDERED COST: Civil Work- Rs 6, 57, 88,182/-
Elec. Work- Rs 28, 69,490/-
Rs 6, 86, 57,672/-

DATE OF START: 04-08-2011

STIPULATED DATE OF
COMPLETION: 02-08-2012

ACTUAL DATE OF Work is Under Progress
COMPLETION:(80% Work is Completed)

TIME ALLOWED : 365 Days


3.SITE LOCATION:-

“Police Station& Staff Quarters at KhajuriKhas near Sonia Vihar, New Delhi”

Advantages of this site:-

1. Land

2. Store

3. Health unit

4. Car parking stand

5. Canteen

6. Connectivity of the yard

7. Ease of transportation Facilities


4. FORMWORK
Formwork is a mould or die used to support and shape the concrete until it attains sufficient to
carry its own weight. The formwork holds the concrete until it hardens to required shape and
size.

SIGNIFICANCE OF FORMWORK

1) Formwork constitutes 30% of the cost and 60% of the time in concrete construction.

2) Quality of concrete finish and soundness of concrete depends very much on the formwork
system

3) Desired shape of concrete is not possible if formwork not done properly.

4) Formwork should be properly designed, fabricated and erected to receive concrete.

5) Accidents happen because of the faulty formwork and scaffolding or staging.

SAFETY IN USING FORMWORK:-

1) Components are light in weight for manual handling.

2) Loose or hanging components are minimal.

3) Appropriate use of tools.

4) Minimum operations are involved in each reuse.


TYPES OF FORMWORK

1) Flex system

2) Quick deck system

3)Aluform system

4) Flex table formwork

Curing work and refilling of earth around footing.


Workers on a construction site building.


CURING V/S COMRESSIVE STRENGTH


COLUMN CONSTRUCTION WORK


6.PLANNING


Planning of a CPWD Project mainly includes:-

Pre-requisites for execution of work.
Deposit works
Preparation of estimates.
Execution of original work.
Expenditure on survey, exhibition.
Register of buildings.
Green building norms.
Preparation and accounting of Standard Measurement book.
Preparation and passing bills for payment.
Documentation of accounts.
General departmental charges.
Contracts and forms.
Preparation of tender documents.
Publicity of tenders
Sale of documents
Earnest money.
Issue of material to contractors.
Issue of tool and plant.
Payment to contractors
Insurance
Losses or damages.
Budgeting
Quality assurance and technical audit wing.
Inspection and Audit by Chief Controller.
Public accounts committee.


6. SEQUENCE OF STRUCTURE WORK
Site clearance
Demarcation of site
Positioning of central coordinate i.e. (0,0,0) as per grid plan
Surveying and layout
Excavation
Bar binding and placement of foundation steel
Shuttering and scaffolding
Concreting
Electrical and plumbing

CONSTRUCTION PROCESS AND MATERIAL USED:-

SITE CLEARANCE-
A number of conditions determine the kind of building that may be erected on a plot of ground.
These conditions may determine where on the lot it may be located. There are also covenants
that are legally binding regulations. These may, for example, set the minimum size of a house,
prohibit utility buildings, or ban rooftop television antennas.
Zoning laws regulate the setback and other factors that play into the equation of house location
on a lot. Septic tanks also require special consideration.
A Certificate of Occupancy is an important piece of paper. It
is the final piece of paper, the sign-off, that says the construction
of the building is complete and it is ready to be occupied. Any town that has adopted the BOCA
or UBC building codes requires a CO. In most instances, the bank making the mortgage loan
requires a certificate of occupation as well.


CONCRETE:-

There are eight types of Portland cement. They are designated by Roman numerals and with an
A suffix on three of them
Normal concrete is made of fine aggregates (sand) and regularaggregates (crushed stone or
gravel), plus water. Concrete will set up hard enough in normal weather in about 3 hours.
However, it takes 28 days for it to reach its fullest strength. Concrete may have admixtures. The
Romans added lard, blood, milk, and other materials to make the concrete more workable.
There are at least 6 known admixtures.

Normal concrete contains a small amount of air by adding anair-entrainment admixture, the
amount of air in the concrete can be increased by 10 percent or more by volume. By using an
accelerator, it is possible to have concrete reach its 28-day full strength in only 7 days. Calcium
chloride is the most common accelerator. Pozzolonas are natural volcanic ash or artificial
materials that react with lime in the wet concrete to form cementing compounds. Fly ash is a
by-product of coal-burning power generating stations.

Romansobtained fly ash from Mount Vesuvius eruptions. Fully loaded concrete mixer trucks
may weigh as much as 80,000 lbs, or 40 tons. If the mixer can’t get close enough to unload the
concrete where needed, it is necessary to use chutes, mixer-mounted conveyors, motorized
buggies, or wheelbarrows.

Another term for rebar is deformed steel bar. This is the steel reinforcement used in concrete
to increase its tensile strength. Three types of bar support material are available: wire, precast
concrete, and moulded plastic. Rebar is supported by chairs made of plastic or welded wire.
Welded-wire fabric (WWF) looks like fencing and is manufactured with plain or deformed cold-
drawn wire.

Slump is a measure of how consistent, fluid, and workable a batch of freshly mixed concrete is.
Any change in the slump may mean that the amount of water, the temperature, hydration, or
setting has changed. Slump is a measure of the amount of water in the mix.


Foundations

Though the foundation supports a building, the earth is the ultimate support. The foundation is
a system comprising foundation wall, footing, and soil. The prime purpose of an efficient
structural foundation system is to transmit the building loads directly to the soil without
exceeding the bearing capacity of the soil. A properly
Designed and constructed foundation system transfers the loads uniformly, minimizes
settlement, and anchors the structure against racking forces and uplift. Because soil type and
bearing capacity are the crucial factors in the foundation system, the foundation must be
designed and built as a system. Too many residential foundations are designed and built
without any concern for the soil.

Types of Foundations

The many types of foundations can be separated into two broad groups: shallow foundations
and deep foundations. Shallow foundations consist of four types: deep basements (8-foot
walls), crawl spaces, slabs-on-grade, and frost-protected shallow foundations. They include
spread footings, mat or raft footings, long footings, and strap footings.
Deep foundations extend considerably deeper into the earth.
They include drilled caissons or piers, groups of piles driven and cast-in-place concrete piles,
and floating foundations.

A number of different construction systems can be used. Casting- place concrete is the most
widely used material for residential foundations, followed by concrete block. Other methods
include precast foundation walls, cast-in-place concrete sandwich panels, and masonry or
concrete piers, all weather wood foundations (AWWF), which are now called permanent wood
foundations (PWF), or preserved.

Wood foundations in Canada. Expanded polystyrene (EPS)Blocks, polyurethane blocks, and
other similar systems using EPS blocks filled with concrete are also used.


FOOTINGS

Footings (which may be square, rectangular, or circular) are strips of concrete or filled concrete
blocks placed under the foundation wall. Gravel or crushed stone footings are used with PWFs.
The purpose of the footings is to transfer the loads from walls, piers, or columns to the soil. The
spread footing is the most common type used to support walls, piers, or columns. The National
Concrete Masonry Association (NCMA) has developed a system of solid.

Pile foundation systems
Foundations relying on driven piles often have groups of piles connected by a Pile cap (a large concrete
block into which the heads of the piles are embedded) to distribute loads which are larger than one
pile can bear. Pile caps and isolated piles are typically connected with grade beams to tie the foundation
elements together; lighter structural elements bear on the grade beams while heavier elements bear
directly on the pile cap.

Monopile foundation
A monopile foundation utilizes a single, generally large-diameter, foundation structural element to
support all the loads (weight, wind, etc.) of a large above-surface structure.

Dried Piles
Also called caissons, drilled shafts, drilled piers, Cast-in-drilled-hole piles (CIDH piles)or Cast-in-
Situ piles. Rotary boring techniques offer larger diameter piles than any other piling method and permit
pile construction through particularly dense or hard strata. Construction methods depend on the geology
of the site. In particular, whether boring is to be undertaken in 'dry' ground conditions or through water-
logged but stable strata - i.e. 'wet boring'.

'Wet' boring also employs a temporary casing through unstable ground and is used when the pile bore
cannot be sealed against water ingress. Boring is then undertaken using a digging bucket to drill through
the underlying soils to design depth. The reinforcing cage is lowered into the bore and concrete is placed
by tremie pipe, following which, extraction of the temporary casing takes place.


Under reamed piles
Underreamed piles have mechanically formed enlarged bases that have been as much as 6 m in
diameter. The form is that of an inverted cone and can only be formed in stable soils. The larger base
diameter allows greater bearing capacity than a straight-shaft pile.

Augercast pile
An augercast pile, often known as a CFA pile, is formed by drilling into the ground with a hollow stemmed
continuous flight auger to the required depth or degree of resistance. No casing is required.

Augercast piles cause minimal disturbance, and are often used for noise and environmentally sensitive
sites. Augercast piles are not generally suited for use in contaminated soils, due to expensive waste
disposal costs. In cases such as these however a displacement pile may provide the cost efficiency of an
augercast pile and minimal environmental impact. In ground containing obstructions or cobbles and
boulders, augercast piles are less suitable as refusal above the design pile tip elevation may be
encountered. In certain cases drill motors that produce more torque and horsepower may be able to
mitigate these events.

Specialty Piles:

1. Micro piles
2. Tripod piles
3. Sheet piles
4. Soldier piles
5. Suction Piles
6. Ad freeze Piles


Types of shallow foundations:

Interlocking concrete blocks called IDR footer-blocks
. The minimum width of the footing is
based on the foundation wall thickness. An 8-inch thick foundation wall would have an 8-inch
wide footing. However, footings are made wider than the foundation wall, and the extra width
projects (or cantilevers) equally beyond each side of the wall.
Contrary to widespread belief, the purpose of footings is not for spreading out and distributing
the loads to the soil. The extra width is used to support the wall forms while the concrete is
poured, or as a base for concrete masonry blocks or brick.

Finishing and Curing Concrete

When working with concrete, certain methods and techniques must be employed to ensure the
best finished product. This chapter discusses the following:

1) Screeding
2) Tamping and jitterbugging
3) Finishing (including Floating, Troweling,Brooming, Grooving, and Edging)
4) Curing (including curing time and curing methods)

1)Screeding

To screed is to strike-off or level slab concrete after pouring. Generally, all the dry materials
used in making quality concrete are heavier than water. Thus, shortly after placement, these
materials will have a tendency to settle to the bottom and force any excess water to the
surface. This reaction is commonly called bleeding. This bleeding usually occurs with non–air-
entrained concrete. It is of utmost importance
that the first operations of placing, screeding, and darbying
be performed before any bleeding takes place.


The concrete should not be allowed to remain in wheelbarrows, buggies, or buckets any longer
than is necessary. It should be dumped and spread as soon as possible and struck-off to the
proper grade, then immediately struck-off, followed at once by darbying. These last two
operations should be performed before any free water is bled to the surface. The concrete
should not be spread over a large area
beforescreeding—nor should a large area be screeded and allowed to remain before darbying.
If any operation is performed on the surface while the bleed water is present, serious scaling,
dusting, or crazing can result. This point cannot be overemphasized and is the basic rule for
successful finishing of concrete surfaces.
The surface is struck off or rodded by moving a straightedge
back and forth with a sawlike motion across the top of the forms or screeds. A small amount of
concrete should always be kept ahead of the straightedge to fill in all the low spots and
maintain a plane surface. For most slab work, screeding is usually a two-person job because of
the size of the slab.

2)Tamping or Jitterbugging

The hand tamper or jitterbug is used to force the large particles of coarse aggregate slightly
below the surface to enable the cement mason to pass a darby over the surface without
dislodging any large aggregate. After the concrete has been struck-off or rodded (and, in some
cases, tamped), it is smoothed with a darby to level any raised spots and fill depressions. Long-
handled floats of either wood ormetal (called bull floats) are sometimes used instead of darbies
to smooth and level the surface.

The hand tamper should be used sparingly and, in most cases,
not at all. If used, it should be used only on concrete having a low slump (1 inch or less) to
compact the concrete into a dense mass. Jitterbugs are sometimes used on industrial floor
construction because the concrete for this type of work usually has a very low slump, with the
mix being quite stiff and perhaps difficult to work.


3)Finishing

When the bleed water and water sheen have left the surface of the concrete, finishing may
begin. Finishing may take one or more of several forms, depending on the type of surface
desired.
Finishing operations must not be overdone, or water under the
surface will be brought to the top. When this happens, a thin layer of cement is also brought up
and later, after curing, the thin layer becomes a scale that will powder off with usage. Finishing
can be done by hand or by rotating power-driven trowels or floats. The size of the job
determines the choice, based on economy.
The type of tool used for finishing affects the smoothness of the concrete. A wood float puts a
slightly rough surface on the concrete.
A steel (or other metal) trowel or float produces a smooth finish.
Extra rough surfaces are given to the concrete by running a stiffbristled broom across the top.

4)Floating

Most sidewalks and driveways are given a slightly roughened surface by finishing with a float.
Floats may be small, hand-held tools , with the work done while kneeling on a board, or
they may be on long handles for working from the edge.
shows a worker using a long-handled float, and shows
the construction details for making a float.
When working from a kneeling board, the concrete must be stiff enough to support the board
and the worker’s weight without deforming.
This will be within two to five hours from the time the surface
water has left the concrete, depending on the type of roof.

A roof includes the roof cover (the upper layer, which protects
against rain, snow, and wind) or roofing, the sheathing to which it is fastened, and the framing
(rafters) that support the other components. Because of its exposure, roofing usually has a
limited life. It is made to be readily replaceable. Roofing may be made of many widely
diversified materials, among which are the following:


1) Wood

These are usually in the form of shingles (uniform
machine-cut) or shakes that are hand-cut. They are seen in
Many areas of the country.

2) Metal or aluminium

Simulates other kinds of roofing.

3) Slate

this may be the natural product or rigid manufactured slabs, often cement asbestos, though
these are on the decline since the controversy over asbestos.

4) Built-up covers of asphalt or tar-impregnated felts, with a mopping of hot
tar or asphalt

these are placed between the pliesand a mopping of tar or asphalt overall. Tar-felt roofs
usuallyhave the top covered with embedded gravel or crushed slag.

5) Roll roofing

Which, as the name implies, is marketed in?
Rolls containing approximately 108 ft2. Each roll is usually
36 inches wide and may be plain or have a coating of colored
Mineral granules. The base is a heavy asphalt-impregnated felt.


6) Asphalt shingles

These are usually in the form
Of strips with two, three, or four tabs per unit. These shingles
Is asphalt with the surface exposed to the weather heavily?
Coated with mineral granules. Because of their fire resistance,
Cost, and durability, asphalt shingles are the most popular roofing material for homes. Asphalt
shingles are available in a wide range of colours, including black and white.
_ Glass fibre shingles—These are made partly of a glass fibre mat (which is waterproof) and
partly of asphalt. Like asphalt shingles, glass fibre shingles come with self-sealing tabs and carry
a Class-A fire-resistance warranty. For the do-it-yourself, they may be of special interest
because they are lightweight, about 220 pounds per square (100 ft2 of roofing).

Roofs
The slope of the roof is frequently a factor in the choice of roofing materials and method used
to put them in place. The lower the pitch of the roof, the greater the chance of wind getting
under the shingles and tearing them out. Interlocking cedar shingles resist this wind prying
better than standard asphalt shingles. For roofs with less than a 4-inch slope per foot, do not
use standard asphalt. Down to 2 inches, use self-sealing asphalt. Roll roofing can be used with
pitches down to 2 inches when lapped 2 inches. For very low-pitched
Slopes, the manufacturers of asphalt shingles recommend that the roof be planned for some
other type of covering.
Aluminium strip roofing virtually eliminates the problem of wind prying, but these strips are
noisy. Most homeowners object to the noise during a rainstorm. Even on porches, the noise is
often annoying to those inside the house.
Spaced roofing boards are sometimes used with cedar shingles.
This is usually done as an economy measure and because the cedar shingles add considerably
to the strength of the roof. The spaced roofing boards reduce the insulating qualities.

Roll Roofing

Roll roofing is an economical cover especially suited
For roofs with low pitches. It is also sometimes used for valley flashing instead of metal. It has a
base of heavy asphalt-impregnated felt with additional coatings of asphalt that are dusted to


prevent adhesion in the roll. The weather surface may be plain or covered with fine mineral
granules. Many different colours are available. One edge of the sheet is left plain (no granules)
where the lap cement
Is applied. For best results, the sheathing must be tight, preferably 1 × 6 tongue-and-groove, or
plywood. If the sheathing is smooth.

These asphalt shingles have a three-dimensional look.
Asphalt shingles are the most popular.

CEMENT
SECOND SHEET
FIRST SHEET

Method of cementing and lapping the first and second
Strips of roll roofing.

Roofing (with no cupped boards or other protuberance), the slate-surfacedroll roofing will
withstand a surprising amount of abrasion from foottraffic, although it is not generally
recommended for that purpose.
Windstorms are the most relentless enemy of roll roofing. If the wind gets under a loose edge,
almost certainly a section will be blown off.

Built-Up Roof (BUR)

A built-up roof is constructed of sheathing paper, a bonded base sheet, perforated felt, asphalt,
and surface aggregates.

The sheathing paper comes in 36-inch-wide rolls and has approximately 432 ft2 per roll. It is a
rosin-size paper and is used to prevent asphalt leakage to the wood deck. The base sheet is a
heavy asphalt-saturated felt that is placed over the sheathing paper.

It is available in 1, 11/2, and 2 squares per roll. The perforatedfelt is one of the primary parts of
a built-up roof. It is saturated with asphalt and has tiny perforations throughout the sheet. The
perforations prevent air entrapment between the layers of felt.


The perforated felt is 36 inches wide and weighs approximately 15 lbs per square. Asphalt is
also one of the basic ingredients of a built-up roof. There are many different grades of asphalt,
but the most commonare low-melt, medium-melt, high-melt, and extra-high-melt

SHEATHING PAPER

BASE SHEET

PERFORATED FELT

ASPHALT AGGREGATE

Sectional plan of a built-up roof

Prior to the application of the built-up roof, the deck should beInspected for soundness. Wood
board decks should be constructed of 3/4-inch seasoned lumber or plywood. Any knotholes


larger than one inch should be covered with sheet metal. If plywood is used as a roof deck it
should be placed with the length at right angles to the rafters and be at least 1/2 inch in
thickness.
The first step in the application of a built-up roof is the placing of sheathing paper and base
sheet. The sheathing paper should be lapped in 2 inches and secured with just enough nails to
hold it in place. The base sheet is then placed with 2-inch side laps and 6-inch end laps. The
base sheet should be secured with 1/2-inch diameter head galvanized roofing nails placed 12
inches on center on the exposed lap. Nails should also be placed down the center of the base
sheet. The nails should be placed in two parallel rows, 12 inches apart.
The base sheet is then coated with a uniform layer of hot asphalt.
While the asphalt is still hot, a layer of roofing felt is placed and mopped with the hot asphalt.
Each succeeding layer of roofing felt is placed and mopped in a similar manner with asphalt.
Each sheet should be lapped 19 inches, leaving 17 inches exposed.
Once the roofing felt is placed, a gravel stop is installed around
the deck perimeter. Two coated layers of felt should extend 6 inches past the roof decking
where the gravel stop is to be installed. When the other plies are placed, the first two layers are
folded over the other layers and mopped in place. The gravel stop is then placed in an 1/8-inch-
thick bed of flashing cement and securely nailed every 6 inches. The ends of the gravel stop
should be lapped 6 inches and packed in flashing cement.

AGGREGATE
GRAVEL STOP
ASPHALT
ROOF CEMENT
NAILS—3" O.C.

The gravel stop.
After the gravel stop is placed, the roof is flooded with hot asphalt and the surface aggregate is
embedded in the flood coat. The aggregates should be hard, dry, opaque, and free of any dust
or foreign matter. The size of the aggregates should range from 1/4 inch Roofing to 5/8 inch.
When the aggregate is piled on the roof, it should be placed on a spot that has been mopped
with asphalt. This technique ensures proper adhesion in all areas of the roof.


7.PROJECT MONITORING :-
PROJECT MONITORING SYSTEM

This is done to continuously track the performance of the project progress, cost sand condition
contribution. Corrective actions can be taken when required and provides data.
The following three reports are made for the tracking-

Monthly progress report

Job cost report

Project performance report.

8. QUALITY:-


The technical audit of works done by CPWD used to be done in-house right from its
inception. The functions of Quality Assurance and Technical Audit of works were shifted
to CVC in the year 1964. On the recommendation of Ranganathan Committee, the
Quality Assurance functions were again shifted to CPWD in the year 1979.

The implementation of Quality Assurance in the field will require close co-operation
among the three agencies, namely (a) field engineers (b) the construction agency, and
(c) the Quality Assurance team at Circle level for strict compliance of Quality Assurance
Procedure forming part of agreement.

Quality Control System Of The Department

Multi level Quality checks have been created in CPWD as detailed below:

Field level

The direct responsibility for ensuring proper quality of work as per approved
specifications for achieving the intended performance and structural, functional and
aesthetical parameters, and the desired life of the building/installation/structure rests
with the construction team of Executive Engineer, Assistant Engineer and Junior
Engineer.

Quality Control team at Circle Level

To keep a watch on the effectiveness/adequacy of Quality Assurance measures at site, a
Quality Assurance team with SE of the circle as its head and comprising of one AE.

The functions of the Quality Assurance team at Circle level are to check the compliance
of Quality Assurance system by the field units, to locate the lapse/deficiency in the
implementation of the Quality Assurance Plan, and to guide the field engineers in
quality related aspects of the work.


Core Wing at Directorate Level

This Core Wing carries out the following main functions to ensure systematic and
comprehensive Assurance of quality in the works: -

· Quality Assurance of works under the Special DG(S&P), (TD), ADG (Border) and
Engineer- in- Chief (CPWD), Delhi.

· Carry out comprehensive examination & technical audit of works.

· To carry out investigations and enquiries with regard to quality related aspects.

Quality Assurance units in the Regions

Quality Assurance works in various Regions are being looked after by the Regional QA
units headed by the Superintending Engineer (TLQA) or Director Works of the Region.

CONTRACT SPECIFICATIONS AND QUALITY ASSURANCE (CSQ)

The CSQ unit of CPWD is responsible for Contract related matters and quality assurance
functions.

The unit headed by a Chief Engineer is located in Nirman Bhawan and has 5 separate
cells headed by superintending engineers to look after specific areas. The specific areas
are

1. Contract & Manual

2. Standards and Specifications


3. Quality Assurance

4. Techno-Legal matters

5. Technology Application & Standards Unit.

The unit is also responsible for enlistment of class-1 contractors in CPWD besides
formulating rules and regulations for enlistment of contractors by different authorities.

All contract related issues, techno legal issues referred to DGW by field units or by other
organisations are dealt by this unit. The responsibility of bringing out schedules and
specifications also rests with the CSQ unit.

10.CONCLUSION:-


It was a wonderful learning experience at CPWD office, IP Bhawan, New Delhi 110002
forSix Weeks. I gained a lot of insight regarding almost every aspect of site. I was given
exposure in almost all the departments at the site, but I had liked to highlight the areas
of safety, quality management, material management and execution.

I hope this experience will surely help me in my future and also in shaping my career.


CPWD Report on Construction of Police Station

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