Patient Counselling. Definition of patient counseling; steps involved in pati...
Summer internship report L&T
1.
SUMMER
INTERNSHIP
REPORT
(7/5/2012
-‐
24/6/2012)
Submitted
by:-‐
Umed
Paliwal
Second
Undergraduate
Student,
Department
of
Civil
Engineering,
Indian
Institute
of
Technology
Kanpur
1
3. Aknowldgement
I
am
very
thankful
to
LARSEN
&
TOUBRO
CONSTRUCTIONS
BUILDINGS
&
FACTORIES
INDIPENDENT
COMPANY
(L&T
CONSTRUCTION,
B&F
IC)
for
having
given
me
the
opportunity
to
undertake
my
summer
training
at
their
prestigious
FORD
INDIA
PVT
LTD,
#
2
PROJECT.
It
was
a
very
good
learning
experience
for
me
to
have
worked
at
this
site
as
this
project
involved
many
unique
construction
practices
and
challenges.
I
would
like
to
convey
my
heartiest
thanks
to
Mr.
Ashutosh
Tripathi,
L&T
Construction.
Ahmadabad
Cluster
Project
Manager
Factory
Division,
who
heartily
welcomed
me
for
the
internship.
I
would
also
like
to
give
my
heart-‐felt
thanks
to
Mr.
S.
K.
Basu,
Project
Co-‐
Ordinator,
Mr.
Sudeep
Ghosh
,QA/QC
Head
who
guided
and
encouraged
me
all
through
the
summer
training
and
imparted
in-‐depth
knowledge
of
the
project.
Also
I
would
like
to
thank
Mr.
G.
M.
Mir,
Planning
Head,
who
assisted
and
guided
me
whenever
I
needed
help.
I
would
like
to
thank
all
the
department
heads
of
L&T
Construction,
B&F
IC,
for
giving
their
precious
time
and
valuable
guidance
during
my
internship
programme.
Last
but
not
the
least;
I
would
like
to
thank
all
the
staff
at
L&T
Construction
,
B&F
IC,
for
being
so
helpful
during
this
summer
training.
Name:
Umed
Paliwal
Date:
16th
June
2012
3
4. INTRODUCTION
ABOUT THE ORGANIZATION:
Larsen & Toubro Limited is the biggest legacy of two Danish Engineers, who built a
world-class organization that is professionally managed and a leader in India's
engineering and construction industry. It was the business of cement that brought the
young Henning Holck-Larsen and S.K. Toubro into India. They arrived on Indian
shores as representatives of the Danish engineering firm F L Smidth & Co in
connection with the merger of cement companies that later grouped into the
Associated Cement Companies.
Together, Holck-Larsen and Toubro, founded the partnership firm of L&T in 1938,
which was converted into a limited company on February 7, 1946. Today, this has
metamorphosed into one of India's biggest success stories. The company has grown
from humble origins to a large conglomerate spanning engineering and construction.
Larsen & Toubro Construction is India’s largest construction organisation. Many of
the country's prized landmarks - its exquisite buildings, tallest structures, largest
industrial projects, longest flyover, and highest viaducts - have been built by it.
Leading-edge capabilities cover every discipline of construction: civil, mechanical,
electrical and instrumentation.
L&T Construction has the resources to execute projects of large magnitude and
technological complexity in any part of the world. The business of L&T Construction
is organized in six business sectors which will primarily be responsible for
Technology Development, Business Development, International Tendering and work
as Investment Centres. Head quarters in Chennai, India. In India, 7 Regional Offices
and over 250 project sites. In overseas it has offices in Gulf and other overseas
locations.
L&T Construction’s cutting edge capabilities cover every discipline of construction –
civil, mechanical, electrical and instrumentation engineering and services extend to
large industrial and infrastructure projects from concept to commissioning.
4
5. L&T Construction has played a prominent role in India’s industrial and infrastructure
development by executing several projects across length and breadth of the country
and abroad. For ease of operations and better project management, in-depth
technology and business development as well as to focus attention on domestic and
international project execution, entire operation of L&T Construction is structured
into four Independent Companies.
• Hydrocarbon IC
• Buildings & Factories IC
• Infrastructure IC
• Metallurgical & Material Handling IC
• Power Transmission & Distribution
• Heavy Engineering
• Shipbuilding
• Power
• Electrical & Automation
• Machinery & Industrial Product
BUILDING & FACTORIES
The Buildings & Factories Independent Company is equipped with the domain
knowledge, requisite expertise and wide-ranging experience to undertake
Engineering, Procurement and Construction (EPC) of all types of building and factory
structures.
• Commercial Buildings & Airports
• Residential Buildings & Factories
RESIDENTIAL BUILDINGS & FACTORIES
L&T undertakes turnkey construction of a wide range of residential buildings and
factory structures. Projects are executed using the cutting edge technology,
sophisticated construction equipment and project management tools for quality, safety
and speed.
• Residential Building
• Factories
5
6. FACTORIES
L&T offers design and turnkey construction of heavy and light factories, cement &
plants including Defence Projects using the latest construction technology, with a
focus on Quality, Safety and Speed. The spectrum covers
• Heavy & Light Factories (HLF) –Automobile & Ancillary Factories, Glass
plants, Food processing Factories, Pharmaceutical plants, Warehouses &
Logistics Parks, Workshop Complexes, Solar thin film manufacturing units,
etc.
• Cement & Plants (C&P) – Cement Plants, Sugar Plants, Distillery Plants,
Food Grain storage structures, Pulp & Paper Mills, Textile Mills etc.
• Defence – Construction of Manufacturing Facilities and Warehouse Facilities
for Defence.
SERVICE SPECTRUM
L&T Construction’s range of services includes:
• Pre-engineering, feasibility studies and detailed project reports.
• Complete civil and structural construction services for all types of buildings,
industrial and infrastructure projects.
• Complete mechanical system engineering including fabrication and erection of
structural steel works; manufacture, supply, erection, testing and
commissioning of plant and equipment; heavy lift erection; high-pressure
piping; fire-fighting; HVAC and LP/ utility piping networks.
• Electrical system design, project electrification, automation and control system
including instrumentation for all type of industrial and telecom projects.
• Design, manufacture, supply and installation of EHV switchyards,
transmission lines.
6
7. QUALITY POLICY
At L&T, Environment, Health & Safety (EHS) is given the highest priority. The EHS
policy enunciated by the Corporate Management lays emphasis on Environment,
Health and Safety through a structured approach and well defined practices. Systems
and procedures have been established for implementing the requisites at all stages of
construction and they are accredited to the International standards of ISO 9001:2008,
ISO 14001:2004 and OHSAS 18001:2007.
7
10. WORK CULTURE
Work Culture emphasises:
• Freedom to experiment
• Continuous learning and training
• Transparency
• Quality in all aspects of work
• Rewards based on performance and potential
TRAINING
Human Resources Department believes that Quality is the hallmark of any successful
venture. Quality Training and Development of Human Resources is realized through:
Identifying training needs within the Organization and designing and implementing
those need based training programs to bring about continuous up-gradation of
knowledge, skills and employee attitudes.
VISION & MISSION
VISION
L&T shall be professionally managed Indian multinational committed to total
customer satisfaction and enhancing shareholder value. L&T shall be an innovative
entrepreneurial and empowered team constantly creating value and attaining global
benchmarks. L&T shall foster a culture of caring trust and continuous learning while
meeting expectations of employees, stakeholders and society.
10
11. MISSION
To achieve excellence in the field of Engineering, Procurement and Construction
through world class practice and standards in quality, Safety and Project
Management.
11
12. PROPOSED – PROJECT
CAR MANUFATURING FACILITY FOR FORD INDIA PVT LTD,
AHMEDABAD, INDIA.
12
13. THE PROJECT DETAILS
PROJECT - CAR MANUFATURING FACILITY
CLIENT - M/S. FORD INDIA PVT LTD.
CONSULTANT - KAJIMA INDIA PVT LTD
CONTRACTOR - L&T CONSTRUCTION BUILDING &
FACTORIES
TYPE OF CONTRACT – LUMPSUM CONTRACT
CONSTRUCTION PERIOD –
DEFECT NOTIFICATION PEROD - 365 DAYS
PROJECT COMPONENT -
• ENGINE SHOP
• PAINT SHOP
• TCF SHOP
• BODY SHOP
• STAMPING
• ROAD AND ADMIN BUILDING
PACKAGE UNDER L&T -
• ENGINE PLANT
• PAINT SHOP –PILING WORK
• TCF SHOP
PROJECT LOCATION AND AREA –
SANAND AHMEDABAD, NEAR TATA
NANO PLANT
AREA UNDER SCOPE – 460 ACRES
CONSULTANT – KAJIMA INDIA PVT LTD
13
14. BRIEF INTRODUCTION OF PROJECT
Ford India has laid the foundation for its new US $1 billion state-of-the-art, integrated
manufacturing facility in Sanand and its future growth on the subcontinent. The total
area of the plant is 406-acre.
• Ford India Sanand facility will deploy global best practices and
technology including a state-of-the-art Paint Shop
• Ford India’s Sanand facility attracts 19 world-class supplier
manufacturers to date
Ford India is laying the foundation for its new US $1 billion state-of-the-art,
integrated manufacturing facility in Sanand and its future growth on the subcontinent.
It will be complete in 2014; the integrated manufacturing facility will have the
capacity to produce an additional 240,000 new Ford vehicles and 270,000 engines per
year for Indian customers and for export market.
The new state-of-the-art assembly plant will be fully integrated to support stamping,
body assembly, paint, trim and final assembly. The paint shop will utilize Ford’s
environmentally friendly rotational dip technology and 3-Wet technology paint
processes, which will improve paint quality, depth and durability, as well as
significantly reducing Volatile Organic Compounds, CO2 emissions and waste.
The idea behind selecting Sanand as project site is, the way the Chennai Port served
the company’s markets in the East and South East Asia, the Gujarat terminal, or a
roll-on roll-off (RoRo) facility, could be used for exports to the western markets like
Mexico, South Africa and the Middle East as and when necessary.
Plus, the State Government has also prioritized land adjacent to the site for supplier
operations. It will be protected by the local government in order to attract and locate
automotive suppliers within close proximity of both the plants.
The project has divided into various packages; L&T has received three packages: first
package is Paint shop(Piling work) , second package Engine and third package is TCF.
The location of project makes it more important due to TATA NANO PLANT by side
and upcoming MARUTI PLANT.
14
15. EHS DEPARTMENT
GENERAL
EHS
RULES
®ULATIONS
1.
No
workmen
below
18
years
and
above
58
years
of
age
shall
be
engaged
for
a
job.
2.
All
workmen
shall
be
screened
before
engaging
them
on
the
job.
Physical
fitness
of
the
person
to
certain
critical
jobs
like
working
at
height
or
other
dangerous
locations
to
be
ensured
before
engaging
the
person
on
work.
The
final
decision
rests
with
the
site
management
to
reject
any
person
on
the
ground
of
physical
fitness.
3.
Visitors
can
enter
the
site
after
EHS
induction
with
the
visitor
pass.
He
should
be
provided
Safety
helmet
&
safety
Shoes,
also
he
should
be
accompanied
with
the
responsible
person
of
that
area.
4.
Smoking
is
strictly
prohibited
at
workplace.
5.
Sub-‐contractors
shall
ensure
adequate
supervision
at
workplaces.
They
shall
ensure
that
all
persons
working
under
them
shall
not
create
any
hazard
to
self
or
to
the
co-‐workers.
6.
Nobody
is
allowed
to
enter
the
site
without
wearing
safety
helmet.
Chinstrap
of
safety
helmet
shall
be
always
on.
7.
No
one
is
allowed
to
work
at
or
more
than
two-‐meter
height
without
wearing
full
body
harness
and
anchoring
the
lanyard
of
full
body
harness
to
firm
support
preferably
at
shoulder
level.
8.
No
one
is
allowed
to
enter
into
workplace
and
work
at
site
without
adequate
foot
protection
(including
female
worker).
9.
Usage
of
eye
protection
equipment
shall
be
ensured
when
workmen
are
engaged
for
grinding,
chipping,
welding
and
gas
cutting.
For
other
jobs,
as
and
when
site
safety
co-‐ordinator
insists
eye
protection
has
to
be
provided.
10.
All
PPEs
like
shoes,
helmet,
full
body
harness
etc.
shall
be
arranged
before
starting
the
job
as
per
recommendation
of
the
EHSO.
11.
Rigid
barrication
must
be
provided
around
the
excavated
pits,
and
barrication
shall
be
maintained
till
the
backfilling
is
done.
Safe
approach
is
to
be
ensured
into
every
excavation.
15
16. 12.
Adequate
illumination
at
workplace
shall
be
ensured
before
starting
the
job
at
night.
13.
All
the
dangerous
moving
parts
of
the
portable/fixed
machinery
being
used
shall
be
adequately
guarded.
14.
Ladders
being
used
at
site
shall
be
adequately
secured
at
bottom
and
top.
Ladder
shall
not
be
used
as
work
platforms.
15.
Erection
zone
and
dismantling
zone
shall
be
barricaded
and
nobody
will
be
allowed
to
stand
under
the
suspended
loads.
16.
Horseplay
is
completely
prohibited
at
workplace.
Running
at
site
is
completely
prohibited
except
in
case
of
emergency.
17.
Material
shall
not
be
thrown
from
the
height.
Proper
arrangement
of
Debris
Chute
can
be
installed.
18.
Other
than
the
electrician
possessing
B
licence
with
red
helmet,
no
one
is
allowed
to
carryout
electrical
connection,
repairs
on
electrical
equipment
or
other
job
related
thereto.
19.
Inserting
of
bare
wires
for
tapping
the
power
from
electrical
socket
is
completely
prohibited.
20.
All
major,
minor
accidents
near
misses
and
unhygienic
conditions
must
be
reported.
21.
All
scaffoldings/
work
platform
shall
meet
the
requirement.
The
width
of
the
working
platform
and
fall
protection
arrangement
shall
be
maintained
as
per
the
Standard.
All
tools
and
tackles
shall
be
inspected
before
use.
Defects
to
be
reported
immediately.
No
lifting
tool&tackle
to
be
used
unless
it
is
certified
by
the
concerned
Engineer
Incharge
/
P&M
engineer.
22.
Good
house
keeping
to
be
maintained.
Passage
shall
not
be
blocked
with
materials.
Material
like
bricks
shall
not
be
stacked
to
the
dangerous
height
at
workplace.
23.
Debris,
scrap
and
other
material
to
be
cleared
then
and
there
from
the
work
place
and
at
the
time
of
closing
of
work
every
day.
24.
Contractors
shall
ensure
that
all
their
workmen
are
following
safe
practices
while
travelling
in
the
company’s
transport
and
staying
at
company’s
accommodations.
25.
Adequate
fire
fighting
equipment
shall
be
made
available
a
workplace
and
persons
to
be
trained
in
fire
fighting
techniques
with
the
co-‐ordination
of
EHSO.
26.
All
the
unsafe
conditions,
unsafe
act
identified
by
the
contractors,
reported
by
site
supervisor
and
/
or
safety
personnel
to
be
corrected
on
priority
basis.
16
17. 27.
No
children
shall
be
allowed
to
enter
the
workplace.
28.
Workwomen
are
not
allowed
to
work
at
high-‐risk
areas.
29.
Other
than
the
Driver/operator,
no
one
shall
travel
in
a
tractor
/
tough
rider
etc.
30.
Wherever
the
vehicle/equipment
has
to
work
near
or
pass
through
the
overhead
electrical
lines,
the
goal
post
shall
be
installed.
31.
Identity
card
should
always
be
displayed
and
shown
when
demanded.
32.
Any
person
found
to
be
interfering
with
or
misusing
fixtures,
fittings
or
equipment
provided
in
the
interest
of
health,
safety
and
welfare
would
be
excluded
from
site.(
like
using
helmet
and
fire
bucket
for
carrying
the
material,
removing
the
handrails,
etc.)
33.
Visitors
must
use
safety
helmet
before
entering
the
Site.
34.
Safety
signs
and
notices
must
be
displayed
and
followed.
35.
Transistor
radios
or
personal
stereos
/
Walkman
must
not
be
used.
36.
All
site
personnel,
for
their
own
safety
and
for
the
safety
of
others,
are
required
to
fully
comply
with
the
agreed
safety
systems/
procedures
and
working
method.
37.
Consumption
of
alcohol
and
drugs
is
prohibited.
38.
No
person
is
to
operate
any
mechanical
/
Electrical
equipment
unless
they
have
been
authorized
and
have
been
certified
as
competent.
39.
Take
Food
only
at
the
designated
area
(like
dinning,
Rest
Room
etc).
The
Waste
food,
PVC/Paper
covers
need
to
be
dumped
in
the
Dustbin.
The
House
keeping
gang
on
regular
intervals
will
clear
this.
Also
hand
/
vessels
should
be
washed
in
the
same
area
with
proper
drainage.
40.
No
workers
should
enter
the
site
with
lunghies
and
dhotis.
41.
No
body
should
sit
/
sleep
on
the
floor
edges.
42.
Don’t
enter
inside
the
room
where
there
is
no
light.
43.
Don’t
take
shelter
under
the
vehicle
or
in
an
electrical
installation
rooms.
44.
Look
for
warnings
signs,
caution
boards
and
other
notices.
45.
Must
be
aware
about
the
locations
of
the
first
aid
canter,
fire
extinguisher,
emergency
assembly
point
and
emergency
siren.
46.
No
floor
opening,
floor
edges
should
be
left
unguarded
47.
Training
is
must
for
all
scaffolders
and
only
trained
scaffolders
should
make
platforms.
48.
Don’t
keep
loose
materials
at
height.
49.
Permission
should
be
taken
for
all
earthworks
from
P&M
Department.
17
18. 50.
Those
who
are
violating
the
safety
norms
will
be
penalized.
51.
Female
workers
should
not
be
engaged
on
work
between
7.P.M.
To
8
A.M.
52.
Physical
fitness
check
shall
be
carried
out
for
crane
operators
&
Drivers.
53.
PPE
Shall
is
provided
to
visitors
at
gate.
54.
No
smoking
sign
boards
shall
be
kept
at
flammable
and
combustible
material
Storage
places.
55.
Debris,
scrap
and
other
materials
shall
be
disposed
daily
at
closing
hours
of
the
day
by
the
same
crew.
56.
Environment
poster
shall
be
displayed
at
site
as
and
when
required
Depending
upon
the
activities
in
progress.
57.
Fire
points
should
be
placed
at
all
required
areas
Use of Personal Protective Equipment and safety devices relevant to
site activities.
• SAFETY APPLIANCES
The
requirement
of
sufficient
number
of
safety
appliances
are
planned
well
in
advance
and
made
available
at
stores.
• HEAD PROTECTION
Every
individual
entering
the
site
must
wear
safety
helmet,
confirming
to
IS:
2925-‐
1984
with
the
chinstrap
fixed
to
the
chin.
• FOOT AND LEG PROTECTION
Safety
footwear
with
steel
toe
is
essential
on
site
to
prevent
crush
injuries
to
our
toes
and
injury
due
to
striking
against
the
object.
• HEARING PROTECTION:
Excessive
noise
causes
damage
to
the
inner
ear
and
permanent
loss
of
hearing.
To
protect
ears
use
ear
plugs
/
ear
muff
as
suitable
18
19. • EYE PROTECTION
Person
carrying
out
grinding
works,
operating
pavement
breakers,
and
those
involved
in
welding
and
cutting
works
should
wear
safety
goggles
&
face
shield
suitably.
Goggles,
Safety
Spectacles,
face
shield
confirm
to
IS:
5983-‐1980.
• EAR PROTECTION
Ear Muff / Earplug should be provided to those working at
places with high sound levels (confirm to IS: 9167-1979).
• HAND AND ARM PROTECTION:
While handling cement and concrete & while carrying out hot
works like gas cutting, grinding & welding usage of hand
gloves is a must to protect the hand,
1)
COTTON
Gloves
(for
materials
handling)-‐IS:
6994-‐1973
2)
RUBEER
Gloves-‐18”
(380/450mm
long)
electrical
grade,
tested
to
15000
Volts
conforming
to
IS:
4770-‐1991
3)
LEATHER
Gloves
–
hot
work
/
handling
of
sharp
edges
• RESPIRATORY PROTECTION
Required
respiratory
protection
according
to
the
exposure
of
hazards
to
be
provided.
• SAFETY NET
Though
it
is
mandatory
to
wear
safety
harness
while
working
at
height
on
the
working
platforms,
safety
nets
of
suitable
mesh
size
shall
be
provided
to
arrest
the
falling
of
person
and
materials
on
need
basis.
• FALL PROTECTION:
To
prevent
fall
of
person
while
working
at
height,
personnel
engaged
more
than
2m
wear
standard
Full
Body
harness
should
be
conforming
to
IS:
3521-‐1999(Third
Revision).
19
20. 1) Lanyard
should
be
of
12mm
Polypropylene
rope
and
of
length
not
more
than
2m.
2) Double
lanyard,
based
on
the
requirement.
20
21. QUALITY ASSURANCE & QUALITY CONTROL
DEPARTMENT
Quality is the key component which propels performance and defines leadership
traits. At L&T Construction, Quality Standards have been internalised and
documented in Quality Assurance manuals. L&T Construction recognizes the crucial
significance of the human element in ensuring quality. Structured training
programmes ensure that every L&T employee is conscious of his/her role and
responsibility in extending L&T Construction’s tradition of leadership through
quality. A commitment to safety springs from a concern for the individual worker –
every one of the thousands braving the rigours of construction at numerous project
sites. L&T, Buildings & Factories IC has a well-established and documented Quality
Management System (QMS) and is taking appropriate steps to improve its
effectiveness in accordance with the requirements of ISO 9001:2008. Relevant
procedures established clearly specify the criteria and methods for effective operation,
control and necessary resources and information to support the operation and
monitoring of these processes.
QUALITY IMPLEMENTATION AT SITE
L&T, Buildings & Factories IC has established procedure for monitoring, measuring
and analyzing of these processes and to take necessary actions to achieve planned
results and continual improvement of these processes. It has also maintained relevant
procedures to identify and exercise required control over outsourced processes, if any.
Systems and procedures have been established for implementing the requisites at all
stages of construction and they are accredited to the International standards of ISO
9001:2008, ISO 14001:2004 and OHSAS 18001:2007. L&T continues to maintain the
trail blazing tradition of meeting the stringent quality standards and adherence to time
schedules in all the projects.
PROJECT QUALITY PLAN (PQP):
The Project Quality Plan is prepared and formulated as a Management Summary of
Quality related activities required to meet the terms of contract. This Quality plan sets
out the Management practices and describes the Quality Management System based
21
22. on PDCA (Plan, Check, Do and Act) Principle. The Project Quality Plan comprises of
two sections:
A. VOLUME I
SCOPE:
The contents of this document are applicable to “SHOP
CONSTRUCTION FOR M/s. FORD INDIA Pvt. Ltd.” and “Construction
of Civil and Structural works for M/s. FORD INDIA Pvt. Ltd. At Sanand,
Gujarat” that will be carried out by Larsen & Toubro Limited, Buildings &
Factories IC for FIPL. In preparation of this document, due regard has been
paid to the requirements of ISO 9001: 2008 series of System Standards.
PURPOSE:
This Project Quality Plan is prepared and formulated as a Management
Summary of Quality related activities required to meet the terms of contract.
This Quality plan sets out the Management practices and describes the Quality
Management System.
TESTS ON CEMENT
CONSISTENCY
AIM
To determine the quantity of water required to produce a cement paste of standard
consistency as per IS: 4031 (Part 4) - 1988.
PRINCIPLE
The standard consistency of a cement paste is defined as that consistency which will
permit the Vicat plunger to penetrate to a point 5 to 7mm from the bottom of the Vicat
mould.
APPARATUS
22
23. VICAT APPARATUS
Vicat apparatus conforming to IS: 5513 - 1976 Balance, whose permissible variation
at a load of 1000g should be +1.0g Gauging trowel conforming to IS: 10086 - 1982
PROCEDURE
i) Weigh approximately 400g of cement and mix it with a weighed quantity of water.
The time of gauging should be between 3 to 5 minutes.
ii) Fill the Vicat mould with paste and level it with a trowel. iii) Lower the plunger
gently till it touches the cement surface.
iv) Release the plunger allowing it to sink into the paste.
v) Note the reading on the gauge.
vi) Repeat the above procedure taking fresh samples of cement and different
quantities of water until the reading on the gauge is 5 to 7mm.
REPORTING OF RESULTS
Express the amount of water as a percentage of the weight of dry cement to the first
place of decimal.
INITIAL AND FINAL SETTING TIME
AIM
To determine the initial and the final setting time of cement as per IS: 4031 (Part 5) -
1988.
APPARATUS
Vicat apparatus conforming to IS: 5513 - 1976 Balance, whose permissible variation
at a load of 1000g should be +1.0g Gauging trowel conforming to IS: 10086 - 1982
PROCEDURE
i) Prepare a cement paste by gauging the cement with 0.85 times the water required to
give a paste of standard consistency
23
24. ii) Start a stop-watch, the moment water is added to the cement.
iii) Fill the Vicat mould completely with the cement paste gauged as above, the mould
resting on a non-porous plate and smooth off the surface of the paste making it level
with the top of the mould. The cement block thus prepared in the mould is the test
block.
INITIAL SETTING TIME
Place the test block under the rod bearing the needle. Lower the needle gently in order
to make contact with the surface of the cement paste and release quickly, allowing it
to penetrate the test block. Repeat the procedure till the needle fails to pierce the test
block to a point 5.0 ± 0.5mm measured from the bottom of the mould . The time
period elapsing between the time, water is added to the cement and the time, the
needle fails to pierce the test block by 5.0 ± 0.5mm measured from the bottom of the
mould, is the initial setting time.
FINAL SETTING TIME
Replace the above needle by the one with an annular attachment.
The cement should be considered as finally set when, upon applying the needle gently
to the surface of the test block, the needle makes an impression therein, while the
attachment fails to do so. The period elapsing between the time, water is added to the
cement and the time, the needle makes an impression on the surface of the test block,
while the attachment fails to do so, is the final setting time.
REPORTING OF RESULTS
The results of the initial and the final setting time should be reported to the nearest
five minutes.
24
25. TESTS ON AGGREGATES
SIEVE ANALYSIS
AIM
To determine the particle size distribution of fine and coarse aggregates by sieving as
per IS: 2386 (Part I) - 1963.
PRINCIPLE
By passing the sample downward through a series of standard sieves, each of
decreasing size openings, the aggregates are separated into several groups, each of
which contains aggregates in a particular size range.
APPARATUS
A SET OF IS SIEVES
i) A set of IS Sieves of sizes - 80mm, 63mm, 50mm, 40mm, 31.5mm, 25mm, 20mm,
16mm, 12.5mm, 10mm, 6.3mm, 4.75mm, 3.35mm, 2.36mm, 1.18mm, 600µm,
300µm, 150µm and 75µm
ii)Balance or scale with an accuracy to measure 0.1 percent of the weight of the test
sample
PROCEDURE
i) The test sample is dried to a constant weight at a temperature of 110 + 5oC and
weighed.
ii) The sample is sieved by using a set of IS Sieves.
iii) On completion of sieving, the material on each sieve is weighed.
iv) Cumulative weight passing through each sieve is calculated as a percentage of the
total sample weight.
v) Fineness modulus is obtained by adding cumulative percentage of aggregates
retained on each sieve and dividing the sum by 100.
25
26. REPORTING OF RESULTS
The results should be calculated and reported as:
i) the cumulative percentage by weight of the total sample
ii) the percentage by weight of the total sample passing through one sieve and
retained on the next smaller sieve, to the nearest 0.1 percent.
WATER ABSORPTION
AIM
To determine the water absorption of coarse aggregates as per IS: 2386 (Part III) -
1963.
APPARATUS
i) Wire basket - perforated, electroplated or plastic coated with wire hangers for
suspending it from the balance
ii) Water-tight container for suspending the basket
iii)Dry soft absorbent cloth - 75cm x 45cm (2 nos.)
iv) Shallow tray of minimum 650 sq.cm area
v) Air-tight container of a capacity similar to the basket
vi) Oven SAMPLE A sample not less than 2000g should be used.
PROCEDURE
i) The sample should be thoroughly washed to remove finer particles and dust,
drained and then placed in the wire basket and immersed in distilled water at a
temperature between 22 and 32oC.
ii) After immersion, the entrapped air should be removed by lifting the basket and
allowing it to drop 25 times in 25 seconds. The basket and sample should remain
immersed for a period of 24 + 1⁄2 hrs. afterwards.
26
27. iii) The basket and aggregates should then be removed from the water, allowed to
drain for a few minutes, after which the aggregates should be gently emptied from the
basket on to one of the dry clothes and gently surface-dried with the cloth,
transferring it to a second dry cloth when the first would remove no further moisture.
The aggregates should be spread on the second cloth and exposed to the atmosphere
away from direct sunlight till it appears to be completely surface-dry. The aggregates
should be weighed (Weight 'A').
iv) The aggregates should then be placed in an oven at a temperature of 100 to 110oC
for 24hrs. It should then be removed from the oven, cooled and weighed (Weight 'B').
REPORTING OF RESULTS
Water absorption = [(A-B)/B] x 100%
TESTS ON FRESH CONCRETE
SLUMP
AIM
To determine the workability of fresh concrete by slump test as per IS: 1199 - 1959.
APPARATUS
i) Slump cone
ii) Tamping rod
PROCEDURE
i) The internal surface of the mould is thoroughly cleaned and applied with a light
coat of oil.
ii) The mould is placed on a smooth, horizontal, rigid and non- absorbent surface.
iii) The mould is then filled in four layers with freshly mixed concrete, each
approximately to one-fourth of the height of the mould.
27
28. iv) Each layer is tamped 25 times by the rounded end of the tamping rod (strokes are
distributed evenly over the cross- section).
v) After the top layer is rodded, the concrete is struck off the level with a trowel.
vi) The mould is removed from the concrete immediately by raising it slowly in the
vertical direction.
vii)The difference in level between the height of the mould and that of the highest
point of the subsided concrete is measured.
viii) This difference in height in mm is the slump of the concrete.
REPORTING OF RESULTS
The slump measured should be recorded in mm of subsidence of the specimen during
the test. Any slump specimen, which collapses or shears off laterally gives incorrect
result and if this occurs, the test should be repeated with another sample. If, in the
repeat test also, the specimen shears, the slump should be measured and the fact that
the specimen sheared, should be recorded.
OMC & MDD TEST
This test is done to determine the maximum dry density and the optimum moisture
content of soil using heavy compaction as per IS: 2720 (Part 8 ) – 1983.The apparatus
used is:-
i) Cylindrical metal mould – it should be either of 100mm dia. and 1000cc volume or
150mm dia. and 2250cc volume and should conform to IS: 10074 – 1982.
ii) Balances – one of 10kg capacity, sensitive to 1g and the other of 200g capacity,
sensitive to 0.01g
iii) Oven – thermostatically controlled with an interior of noncorroding material to
maintain temperature between 105 and 110oC
iv) Steel straightedge – 30cm long
v) IS Sieves of sizes – 4.75mm, 19mm and 37.5mm
28
29. PREPARATION OF SAMPLE
A representative portion of air-dried soil material, large enough to provide about 6kg
of material passing through a 19mm IS Sieve (for soils not susceptible to crushing
during compaction) or about 15kg of material passing through a 19mm IS Sieve (for
soils susceptible to crushing during compaction), should be taken. This portion should
be sieved through a 19mm IS Sieve and the coarse fraction rejected after its
proportion of the total sample has been recorded. Aggregations of particles should be
broken down so that if the sample was sieved through a 4.75mm IS Sieve, only
separated individual particles would be retained.
Procedure To Determine The Maximum Dry Density And The Optimum
Moisture Content Of Soil
A) Soil not susceptible to crushing during compaction –
i) A 5kg sample of air-dried soil passing through the 19mm IS Sieve should be taken.
The sample should be mixed thoroughly with a suitable amount of water depending
on the soil type (for sandy and gravelly soil – 3 to 5% and for cohesive soil – 12 to
16% below the plastic limit). The soil sample should be stored in a sealed container
for a minimum period of 16hrs.
ii) The mould of 1000cc capacity with base plate attached, should be weighed to the
nearest 1g (W1 ). The mould should be placed on a solid base, such as a concrete floor
or plinth and the moist soil should be compacted into the mould, with the extension
attached, in five layers of approximately equal mass, each layer being given 25 blows
from the 4.9kg rammer dropped from a height of 450mm above the soil. The blows
should be distributed uniformly over the surface of each layer. The amount of soil
used should be sufficient to fill the mould, leaving not more than about 6mm to be
struck off when the extension is removed. The extension should be removed and the
compacted soil should be levelled off carefully to the top of the mould by means of
the straight edge. The mould and soil should then be weighed to the nearest gram
(W2).
iii) The compacted soil specimen should be removed from the mould and placed onto
the mixing tray. The water content (w) of a representative sample of the specimen
should be determined.
29
30. iv) The remaining soil specimen should be broken up, rubbed through 19mm IS Sieve
and then mixed with the remaining original sample. Suitable increments of water
should be added successively and mixed into the sample, and the above operations i.e.
ii) to iv) should be repeated for each increment of water added. The total number of
determinations made should be at least five and the moisture contents should be such
that the optimum moisture content at which the maximum dry density occurs,
lies within that range.
B) Soil susceptible to crushing during compaction –
Five or more 2.5kg samples of air-dried soil passing through the 19mm IS Sieve,
should be taken. The samples should each be mixed thoroughly with different
amounts of water and stored in a sealed container as mentioned in Part A)
C) Compaction in large size mould –
For compacting soil containing coarse material upto 37.5mm size, the 2250cc mould
should be used. A sample weighing about 30kg and passing through the 37.5mm IS
Sieve is used for the test. Soil is compacted in five layers, each layer being given 55
blows of the 4.9kg rammer. The rest of the procedure is same as above.
REPORTING OF RESULTS
Bulk density Y(gamma) in g/cc of each compacted specimen should be
calculated from the equation,
Y(gamma) = (W2-W1)/ V
where, V = volume in cc of the mould.
The dry density Yd in g/cc
Yd = 100Y/(100+w)
The dry densities, Yd obtained in a series of determinations should be plotted against
the corresponding moisture contents,w. A smooth curve should be drawn through the
resulting points and the position of the maximum on the curve should be determined
The dry density in g/cc corresponding to the maximum point on the moisture
content/dry density curve should be reported as the maximum dry density to the
nearest 0.01. The percentage moisture content corresponding to the maximum dry
density on the moisture content/dry density curve should be reported as the optimum
30
31. moisture content and quoted to the nearest 0.2 for values below 5 percent, to the
nearest 0.5 for values from 5 to 10 percent and to the nearest whole number for values
exceeding 10 percent.
WATER CONTENT
OVEN DRYING METHOD
AIM
To determine the water content in soil by oven drying method as per IS: 2720 (Part II)
- 1973.
PRINCIPLE
The water content (w) of a soil sample is equal to the mass of water divided by the
mass of solids.
APPARATUS
i) Thermostatically controlled oven maintained at a temperature of 110 ± 5oC
ii) Weighing balance, with an accuracy of 0.04% of the weight of the soil taken
iii) Air-tight container made of non-corrodible material with lid
iv) Tongs
SAMPLE
The soil specimen should be representative of the soil mass. The quantity of the
specimen taken would depend upon the gradation and the maximum size of particles
as under:
PROCEDURE
i) Clean the container, dry it and weigh it with the lid (Weight 'W1').
ii) Take the required quantity of the wet soil specimen in the container and weigh it
with the lid (Weight 'W2').
iii) Place the container, with its lid removed, in the oven till its weight becomes
constant (Normally for 24hrs.).
iv) When the soil has dried, remove the container from the oven, using tongs.
v) Find the weight 'W3' of the container with the lid and the dry soil sample.
31
32. REPORTING OF RESULTS
The water content w = [(W2 − W3) ×100%] /(W3 −W1)
CALCIUM CARBIDE METHOD(RAPID MOISTURE METER TEST)
AIM
To determine the water content in soil by calcium carbide method as per IS: 2720
(Part II) - 1973.
PRINCIPLE
It is a method for rapid determination of water content from the gas pressure
developed by the reaction of calcium carbide with the free water of the soil. From the
calibrated scale of the pressure gauge the percentage of water on total mass of wet soil
is obtained and the same is converted to water content on dry mass of soil.
APPARATUS
i) Metallic pressure vessel, with a clamp for sealing the cup, alongwith a gauge
calibrated in percentage water content
ii) Counterpoised balance, for weighing the sample
iii) Scoop, for measuring the absorbent (Calcium Carbide)
iv) Steel balls - 3 steel balls of about 12.5mm dia. and 1 steel ball of 25mm dia.
v) One bottle of the absorbent (Calcium Carbide)
PREPARATION OF SAMPLE
Sand - No special preparation. Coarse powders may be ground and pulverized.
Cohesive and plastic soil - Soil is tested with addition of steel ball in the pressure
vessels.
The test requires about 6g of sample.
PROCEDURE
i) Set up the balance, place the sample in the pan till the mark on the balance arm
matches with the index mark.
ii) Check that the cup and the body are clean.
iii) Hold the body horizontally and gently deposit the levelled, scoop-full of the
32
33. absorbent (Calcium Carbide) inside the chamber.
iv) Transfer the weighed soil from the pan to the cup.
v) Hold cup and chamber horizontally, bringing them together without disturbing the
sample and the absorbent.
vi) Clamp the cup tightly into place. If the sample is bulky, reverse the above
placement, that is, put the sample in the chamber and the absorbent in the cup.
vii) In case of clayey soils, place all the 4 steel balls (3 smaller and 1 bigger) in the
body alongwith the absorbent.
viii) Shake the unit up and down vigorously in this position for about 15 seconds.
ix) Hold the unit horizontally, rotating it for 10 seconds, so that the balls roll around
the inner circumference of the body.
x) Rest for 20 seconds.
xi) Repeat the above cycle until the pressure gauge reading is constant and note the
reading. Usually it takes 4 to 8 minutes to achieve constant reading. This is the water
content (m) obtained on wet mass basis.
xii) Finally, release the pressure slowly by opening the clamp screw and taking the
cup out, empty the contents and clean the instrument with a brush.
REPORTING OF RESULTS
The water content on dry mass basis,
W = (m/100 – m)*100%
IN-SITU DRY DENSITY
CORE CUTTER METHOD
AIM
To determine the in-situ dry density of soil by core cutter method as per IS: 2720 (Part
XXIX) - 1975.
APPARATUS
i) Cylindrical core cutter
ii) Steel dolley
iii) Steel rammer
33
34. iv) Balance, with an accuracy of 1g
v) Straightedge
vi) Square metal tray - 300mm x 300mm x 40mm
vii) Trowel
PROCEDURE
i) The internal volume (V) of the core cutter in cc should be calculated from its
dimensions which should be measured to the nearest 0.25mm.
ii) The core cutter should be weighed to the nearest gram (W1).
iii) A small area, approximately 30cm square of the soil layer to be tested should be
exposed and levelled. The steel dolly should be placed on top of the cutter and the
latter should be rammed down vertically into the soil layer until only about 15mm of
the dolly protrudes above the surface, care being taken not to rock the cutter. The
cutter should then be dug out of the surrounding soil, care being taken to allow some
soil to project from the lower end of the cutter. The ends of the soil core should then
be trimmed flat in level with the ends of the cutter by means of the straightedge.
iv) The cutter containing the soil core should be weighed to the nearest gram (W2).
v) The soil core should be removed from the cutter and a representative sample should
be placed in an air-tight container and its water content (w) determined as in Para 5.1.
REPORTING OF RESULTS
Bulk density of the soil γ = (W2 −W1)/V g /cc
Dry density of the soil γd = [100γ/100+w] g cc
MIX DESIGN
Concrete is the basic engineering material used in most of the civil engineering
structures. Its popularity as basic building material in construction is because of, its
economy of use, good durability and ease with which it can be manufactured at site.
The ability to mould it into any shape and size, because of its plasticity in green stage
and its subsequent hardening to achieve strength, is particularly useful.
Concrete like other engineering materials needs to be designed for properties like
strength, durability, workability and cohesion. Concrete mix design is the science of
deciding relative proportions of ingredients of concrete, to achieve the desired
34
35. properties in the most economical way.
With advent of high-rise buildings and pre-stressed concrete, use of higher grades of
concrete is becoming more common. Even the revised IS 456-2000 advocates use of
higher grade of concrete for more severe conditions of exposure, for durability
considerations. With advent of new generation admixtures, it is possible to achieve
higher grades of concrete with high workability levels economically. Use of mineral
admixtures like fly ash, slag, meta kaolin and silica fume have revolutionised the
concrete technology by increasing strength and durability of concrete by many folds.
Mix design of concrete is becoming more relevant in the above-mentioned scenario.
However, it should be borne in mind that mix design when adopted at site should
be implemented with proper understanding and with necessary precautions.
Durocrete mix design manual is an attempt to increase the awareness among the
users, about concrete mix design. It is made with intention of serving as ready
reckoner for personnel, implementing mix design at site.
Advantages of mix design
Mix design aims to achieve good quality concrete at site economically.
I. Quality concrete means Better strength Better imperviousness and durability Dense
and homogeneous concrete
II. Economy
a) Economy in cement consumption
It is possible to save up to 15% of cement for M20 grade of concrete with the help of
concrete mix design. In fact higher the grade of concrete more are the savings. Lower
cement content also results in lower heat of hydration and hence reduces shrinkage
cracks.
b) Best use of available materials:
Site conditions often restrict the quality and quantity of ingredient materials. Concrete
mix design offers a lot of flexibility on type of aggregates to be used in mix design.
Mix design can give an economical solution based on the available materials if they
meet the basic IS requirements. This can lead to saving in transportation costs from
longer distances.
c) Other properties:
Mix design can help us to achieve form finishes, high early strengths for early
deshuttering, concrete with better flexural strengths, concrete with pumpability and
35
36. concrete with lower densities.
What is mix design?
Concrete is an extremely versatile building material because, it can be designed for
strength ranging from M10 (10Mpa) to M100 (100 Mpa) and workability ranging
from 0 mm slump to 150 mm slump. In all these cases the basic ingredients of
concrete are the same, but it is their relative proportioning that makes the
difference.
Basic Ingredients of Concrete: -
1. Cement – It is the basic binding material in concrete.
2. Water – It hydrates cement and also makes concrete workable.
3. Coarse Aggregate – It is the basic building component of concrete.
4. Fine Aggregate – Along with cement paste it forms mortar grout and fills the voids
in the coarse aggregates.
5. Admixtures – They enhance certain properties of concrete e.g. gain of strength,
workability, setting properties, imperviousness etc
Concrete needs to be designed for certain properties in the plastic stage as well as in
the hardened stage.
Properties desired from concrete in plastic stage: -
Workability Cohesiveness Initial set retardation
Properties desired from concrete in hardened stage: -
Strength Imperviousness Durability
Concrete mix design is the method of correct proportioning of ingredients of
concrete, in order to optimise the above properties of concrete as per site
requirements.
In other words, we determine the relative proportions of ingredients of concrete
to achieve desired strength & workability in a most economical way.
Information required for concrete mix design
The site engineer should give following information while giving material for mix
36
37. design to the mix design laboratory: -
Grade of concrete (the characteristic strength)
Workability requirement in terms of slump
Other properties (if required): -
i. Retardation of initial set (to avoid cold joints in case of longer leads or for ready
mix concrete)
ii. Slump retention (in case of ready mix concrete)
iii. Pumpability (In case of ready mix concrete)
iv.Acceleration of strength (for precast members or where early deshuttering is
desired)
v. Flexural strength (normally required for concrete pavements)
Ascertain whether condition of exposure to concrete is mild, moderate severe or very
severe. Proper investigation of soil should be done to ascertain presence of sulphates
& chlorides, in case of doubt.
Following factors indicate degree of control at site: -
Batching – weigh batching / volume batching.
Type of aggregates – whether mixed graded aggregate will be used or 20mm, 10mm
aggregates will be used separately.
Testing of concrete – whether casting & testing of concrete cubes will be done
regularly at site.
Source of aggregate – whether sources of sand and aggregate will be standardised or
likely to change frequently.
Supervision – whether qualified staff will be present to supervise concreting work and
make necessary corrections e.g. correction for moisture in sand and changes in
material properties.
Site laboratory – whether the site will have necessary laboratory equipment like
sieves, weighing balance etc. to check material properties.
Material properties and how they affect mix design Cement
a) Strength/grade of cement: Grade of cement e.g. 43 grade or 53 grade can
influence the mix design. Grade of cement indicates minimum strength of cement in
N/mm2 tested as per standard conditions laid down by IS codes (OPC 43 grade – IS
8112-1989, OPC 53 grade – IS 12269 – 1987 e.g. a 43 grade cement should give
minimum strength of 43 N/mm2 at 28 days). Higher the strength of cement, higher is
37
38. the strength of concrete for the same water/cement ratio. In other words a higher
strength of cement permits use of higher water/cement ratio to achieve the same
strength of concrete. The IS 10262 - 1982 for mix design gives the different curves of
cement based on the actual strength of cement on 28th day. These cement curves give
water/cement ratio required to achieve a given target strength. Information on grade
of cement may not be as useful as the actual 28days strength of cement. This is
because some of the 43 grade cements practically give strengths more than 53
N/mm2. When a 53-grade cement is stored for a long time, its strength may
deteriorate and become equivalent to 33 grade or 43 grade cement. Thus 28 days
strength of cement is required to select the cement curve before starting the mix
design. Finding the 28 days strengths of cement consumes time. It is not practical in
many cases to wait for 28 days strength of cement to start the mix design. In such
cases 28 days strength reports of the manufacturers may be used and can be
supplemented by accelerated strength of cement found by reference mix method
given in IS 10262 Apart from strength of cement, the type of cement e.g. Ordinary
Portland Cement, pozzolona cement (blended cement) etc, is also important factor
affecting the gain of strength. Blended cements achieve strengths later than Ordinary
Portland Cements and require extended curing period. However, use of these cements
result in more durable concrete by offering greater resistance to sulphate and chloride
attacks.
b) Initial & Final setting time of cement: The initial setting time of cement indicates
the time after which the cement paste looses its plasticity. Operations like mixing,
placing and compaction should be completed well before the initial setting time of
cement .The minimum initial setting time specified by IS 456 –2000 (Clause 5.4.1.3
page no 14 and IS 8112-1989 page 2) is 30 minute. Most of the cements produced
today give an initial set of more than 60 minutes. Beginning of hardening of cement
paste indicates the final setting of cement. The maximum limit for final setting
permitted by IS 8112: 1989 (Clause 6.3. page 2) is 600 minute. Most of the cements
produced today give a final setting of between 3 to 5 hours. Curing can be started
after final setting of cement. The initial setting and the final setting can be extended
by use of retarders in order to avoid cold joints when lead-time for placing concrete is
longer.
Fine Aggregates
a) Gradation of fine aggregates: The gradation of sand is given by sieve analysis.
38
39. The sieve analysis is done by passing sand through a set of standard sieves and
finding out cumulative passing percentage through each sieve. The IS 383 – 1970
classifies fine aggregates in 4 zones starting from zone I representing coarse sand, to
zone IV representing the finest sand. The limits of cumulative percentage passing for
each sieve for above zones are given in table 4 of IS 383 The fineness of sand found
by sieve analysis governs the proportion of sand in concrete .The overall fineness of
sand is given by factor called fineness modulus. Fineness Modulus is given by
division of the summation of cumulative retained fractions for standard sieves up to
150-micron sieve size by 100.
c) Silt Content by weight: This is found by wet-sieving of sand and material passing
75 micron sieve is classified as silt. This silt affects the workability of concrete,
results in higher water/cement ratio and lower strength. The upper limit for 75-micron
sieve in case of sand is 3% by weight. This limit has however been extended to 15%
in case of crushed sand in IS 383 – 1970 Table 1
Coarse Aggregate
a) Maximum size of coarse aggregate: Maximum size of aggregate is the standard
sieve size (40mm, 25mm, 20mm, 12.5mm, 10mm) through which at least 90% of
coarse aggregate will pass. Maximum size of aggregate affects the workability and
strength of concrete. It also
influences the water demand for getting a certain workability and fine aggregate
content required for achieving a cohesive mix. For a given weight, higher the
maximum size of aggregate, lower is the surface area of coarse aggregates and vice
versa. As maximum size of coarse aggregate reduces, surface area of coarse aggregate
increases. Higher the surface area, greater is the water demand to coat the particles
and generate workability. Smaller maximum size of coarse aggregate will require
greater fine aggregate content to coat particles and maintain cohesiveness of concrete
mix. Hence 40 mm down coarse aggregate will require much less water than 20 mm
down aggregate. In other words for the same workability, 40mm down aggregate will
have lower water/cement ratio, thus higher strength when compared to 20mm down
aggregate. Because of its lower water demand, advantage of higher maximum size of
coarse aggregate can be taken to lower the cement consumption. Maximum size of
aggregate is often restricted by clear cover and minimum distance between the
39
40. reinforcement bars. Maximum size of coarse aggregate should be 5 mm less than clear
cover or minimum distance between the reinforcement bars, so that the aggregates can
pass through the reinforcement in congested areas, to produce dense and homogenous
concrete.
It is advantageous to use greater maximum size of coarse aggregate for concrete
grades up to M 35 where mortar failure is predominant. Lower water/cement ratio will
mean higher strength of mortar (which is the weakest link) and will result in higher
strength of concrete. However, for concrete grades above M40, bond failure becomes
predominant. Higher maximum size of aggregate, which will have lower area of
contact with cement mortar paste, will fail earlier because of bond failure. Hence for
higher grades of concrete (M40 and higher) it is advantageous to use lower maximum
size of aggregate to prevent bond failure.
The fineness modulus of sand varies from 2.0 to 4.0; higher the FM coarser is the
sand.
Type of Sand
Fine Medium Coarse
- FM
- 2.0 to 2.8 - 2.8 to 3.2 - 3.2 and above
b) Specific gravity of fine aggregates: This is the ratio of solid density particles to
the density of water. Higher the specific gravity, heavier is the sand particles and
higher is the density of concrete. Conversely a lower specific gravity of sand will
result in lower density of concrete. Specific gravity of sand is found with help of
pycnometer bottles. The specific gravity of fine aggregates found in Pune region
varies from 2.6 to 2.8.
b) Grading of coarse aggregate: The coarse aggregate grading limits are given in IS
383 – 1970 - table 2, Clause 4.1 and 4.2 for single size aggregate as well as graded
aggregate. The grading of coarse aggregate is important to get cohesive & dense
concrete. The voids left by larger coarse aggregate particles are filled by smaller
coarse aggregate particles and so on. This way, the volume of mortar (cement-sand-
water paste) required to fill the final voids is minimum. However, in some cases gap
graded aggregate can be used where some intermediate size is not used. Use of gap-
graded aggregate may not have adverse effect on strength.
By proper grading of coarse aggregate, the possibility of segregation is minimised,
especially for higher workability. Proper grading of coarse aggregates also improves
40
41. the compactability of concrete.
c) Shape of coarse aggregate: Coarse aggregates can have round, angular, or
irregular shape. Rounded aggregates because of lower surface area will have lowest
water demand and also have lowest mortar paste requirement. Hence they will result
in most economical mixes for concrete grades up to M35. However, for concrete
grades of M40 and above (as in case of max size of aggregate) the possibility of bond
failure will tilt the balance in favour of angular aggregate with more surface area.
Flaky and elongated coarse aggregate particles not only increase the water demand
but also increase the tendency of segregation. Flakiness and elongation also reduce
the flexural strength of concrete. Specifications by Ministry of Surface Transport
restrict the combined flakiness and elongation to 30% by weight of coarse aggregates.
d) Strength of coarse aggregate: Material strength of coarse aggregate is indicated
by crushing strength of rock, aggregate crushing value, aggregate impact value,
aggregate abrasion value. In Maharashtra the coarse aggregates are made of basalt
rock, which has strengths in excess of 100 N/mm2. Hence aggregates rarely fail in
strength.
e) Aggregate Absorption: Aggregate can absorb water up to 2 % by weight when in
bone dry state, however, in some cases the aggregate absorption can be as high as 5%.
Aggregate absorption is used for applying a correction factor for aggregates in dry
condition and determining water demand of concrete in saturated surface dry
condition.
Decision Variables in Mix Design
A. Water/cement ratio B. Cement content C. Relative proportion of fine & coarse
aggregates D. Use of admixtures
A. Water/cement ratio
Water to cement ratio (W/C ratio) is the single most important factor governing the
strength and durability of concrete. Strength of concrete depends upon W/C ratio
rather than the cement content. Abram’s law states that higher the water/cement ratio,
lower is the strength of concrete. As a thumb rule every 1% increase in quantity of
water added, reduces the strength of concrete by 5%. A water/cement ratio of only
0.38 is required for complete hydration of cement. (Although this is the theoretical
limit, water cement ratio lower than 0.38 will also increase the strength, since all the
cement that is added, does not hydrate) Water added for workability over and above
41
42. this water/cement ratio of 0.38, evaporates leaving cavities in the concrete. These
cavities are in the form of thin capillaries. They reduce the strength and durability of
concrete. Hence, it is very important to control the water/cement ratio on site. Every
extra lit of water will approx. reduce the strength of concrete by 2 to 3 N/mm2
and increase the workability by 25 mm. As stated earlier, the water/cement ratio
strongly influences the permeability of concrete and durability of concrete.
B. Cement content
Cement is the core material in concrete, which acts as a binding agent and imparts
strength to the concrete. From durability considerations cement content should not be
reduced below 300Kg/m3 for RCC. IS 456 –2000 recommends higher cement
contents for more severe conditions of exposure of weathering agents to the concrete.
It is not necessary that higher cement content would result in higher strength. In fact
latest findings show that for the same water/cement ratio, a leaner mix will give better
strength. However, this does not mean that we can achieve higher grades of concrete
by just lowering the water/cement ratio. This is because lower water/cement ratios
will mean lower water contents and result in lower workability. In fact for achieving a
given workability, a certain quantity of water will be required. If lower water/cement
ratio is to be achieved without disturbing the workability, cement content will have to
be increased. Higher cement content helps us in getting the desired workability at a
lower water/cement ratio. In most of the mix design methods, the water contents to
achieve different workability levels are given in form of empirical relations.
Water/cement ratios required to achieve target mean strengths are interpolated from
graphs given in IS 10262 Clause 3.1 and 3.2 . The cement content is found as follows:
-
Cement content (Kg/m3) =
Water required achieving required workability (Lit/m3)
Water/cement ratio
Thus, we see that higher the workability of concrete, greater is cement content
required and vice versa. Also, greater the water/cement ratio, lower is the cement
content required and vice versa.
C. Relative proportion of fine, coarse aggregates gradation of aggregates
Aggregates are of two types as below:
a. Coarseaggregate(Metal): Theseareparticlesretainedonstandard IS 4.75mm sieve.
b. Fine aggregate(Sand): These are particles passing standard IS 4.75mm sieve.
42
43. Proportion of fine aggregates to coarse aggregate depends on following:
i. Fineness of sand: Generally, when the sand is fine, smaller proportion of it is
enough to get a cohesive mix; while coarser the sand, greater has to be its proportion
with respect to coarse aggregate.
ii. Size & shape of coarse aggregates: Greater the size of coarse aggregate lesser is
the surface area and lesser is the proportion of fine aggregate required and vice versa.
Flaky aggregates have more surface area and require greater proportion of fine
aggregates to get cohesive mix. Similarly, rounded aggregate have lesser surface area
and require lesser proportion of fine aggregate to get a cohesive mix.
iii. Cement content: Leaner mixes require more proportion of fine aggregates than
richer mixes. This is because cement particles also contribute to the fines in concrete.
D. Use of admixtures
Now days, admixtures are rightly considered as the fifth ingredient of concrete. The
admixtures can change the properties of concrete. Commonly used admixtures are as
follows:
i. Plasticisers & superplasticisers
ii. Retarders
iii. Accelerators
iv. Air entraining agents
v. Shrinkage compensating admixtures
vi. Water proofing admixtures
i. Plasticisers & super plasticisers
Plasticisers help us in increasing the workability of concrete without addition of
water. It means that we can achieve lower water/cement ratio without reducing the
workability at the same cement content. Cement particles tend to form flocs trapping a
part of mixing water in them. Hence not all the water added is useful for generating
workability. Plasticisers work as dispersion agents (de flocculent) releasing the water
trapped in the flocs resulting in workability. Use of plasticisers is economical as the
cost incurred on them is less than the cost of cement saved; this is more so in concrete
designed for higher workability.
Compatibility of plasticisers with the cement brand should be checked before use.
Also plasticiser should not be added in dry concrete mix.
43
44. Plasticizers are used for moderate increase of workability whereas super plasticizers
are used where very large increase in workability is required. Plasticizers are normally
lignosulphonated formaldehydes and are normally added in small dosages. This is
because large dosage can cause permanent retardation in concrete and adversely affect
its strength. Super plasticizers are naphthalene or melamine based formaldehyde.
They can be used in large dosages without any adverse effect on concrete. This is
contrary to popular perception that term super plasticizers means more potent, hence
lower dosage is required when compared to normal plasticizers. In practice super
plasticizers are used in large dosages for generating higher workability and better
slump retention. Compatibility of plasticizers with cement should be ascertained
before use in concrete. Since action of plasticizers is based on ionic dispersion certain
plasticizers are more effective with certain cements, thus requiring lower dosages.
Non-compatible plasticizers if used, will not adversely affect the concrete, but its high
dosage will make it uneconomical for use.
ii. Retarders:
They are used for retarding (delaying) the initial setting time of concrete. This is
particularly required when longer placing times are desired as in case of ready mixed
concrete. Retarders are commonly used to prevent formation of cold joints when
casting large concrete. Retarders are normally added in lower dosages as large
dosages can cause permanent retardation in concrete. Retarders are recommended in
case of hot weather concreting to prevent early loss of slump. It is important to note
that retarders reduce early strength of concrete e.g. 1-day and 3-day strength.
However, 28 days strength is not affected.
iii. Accelerators
They are used for accelerating the initial strength of concrete. Typical accelerators
increase the 1-day (up to 50 %) and 3-days (up to 30 %) strength of concrete. Most of
the accelerators show little increase for 7 days strength. For this reason, accelerators
are commonly used in precast concrete elements for early removal of moulds.
Accelerators may not be much useful for early deshuttering where early strengths are
required in range of 5 to 7 days. This is because accelerators are expensive and their
ability to increase strengths decreases after 3-5 days. A better option for early
deshuttering would be the use of plasticizers, reducing the water/cement ratio and
achieving a higher grade of concrete. It is believed that accelerators may cause
retrogression of strength after 28 days when compared with normal concrete.
44
45. Concrete Mix Design Methods
The basic objective of concrete mix design is to find the most economical proportions
(Optimisation) to achieve the desired end results (strength, cohesion, workability,
durability, As mentioned earlier the proportioning of concrete is based on certain
material properties of cement, sand and aggregates. Concrete mix design is basically a
process of taking trials with certain proportions. Methods have been developed to
arrive at these proportions in a scientific manner. No mix design method directly
gives the exact proportions that will most economically achieve end results.
These methods only serve as a base to start and achieve the end results in the
fewest possible trials.
The code of practice for mix design-IS 10262 clearly states following: - The basic
assumption made in mix design is that the compressive strength of workable
concretes, by and large, governed by the water/cement ratio. Another most convenient
relationship applicable to normal concrete is that for a given type, shape, size and
grading of aggregates, the amount of water determines its workability. However, there
are various other factors which affect the properties of concrete, for example the
quality & quantity of cement, water and aggregates; batching; transportation; placing;
compaction; curing; etc. Therefore, the specific relationships that are used in
proportioning concrete mixes should be considered only as the basis for trial, subject
to modifications in the light of experience as well as for the particular materials used
at the site in each case. Different mix design methods help us to arrive at the trial mix
that will give us required strength, workability, cohesion etc. These mix design
methods have same common threads in arriving at proportions but their method of
calculation is different. Basic steps in mix design are as follows:
Find the target mean strength.
Determine the curve of cement based on its strength.
Determine water/cement ratio.
Determine cement content.
Determine fine and coarse aggregate proportions
45
47. PROJECT EXECUTION
METHOD STATEMENT FOR CIVIL AND MECHANICAL
1. METHOD STATEMENT FOR CIVIL
METHOD STATEMENT FOR SURVEY WORKS
OBJECTIVE: To formulate guidelines for Setting out and routine survey
works
REFERENCE:
1. Drawing
2. Technical Specifications for Civil works
3. Inspection and test plan
4. Survey Layout showing control stations
MAJOR EQUIPMENTS: Calibrated Auto - level, Theodolite (LC-1"), Total
Station and necessary measuring tools
METHOD STATEMENT FOR BUILDING UP OF PILES UPTO
CUTOFF LEVEL
OBJECTIVE: Building up of Plies up-to cut-off levels
REFERENCE:
1. Drawing
2. Technical Specifications for Civil works
3. Technical Data sheet of Nitobond EP
METHOD STATEMENT FOR REINFORCEMENT WORK
1. OBJECTIVE: This procedure covers method for cutting, bending and
tying of reinforcement and inspection of works.
2. REFERENCE: Reinforcement placing and handling shall be as per IS-456
MAJOR EQUIPMENTS: Bar cutting & bending machines, rebar tying tool.
METHOD STATEMENT FOR FORMWORK
1. OBJECTIVE: This Procedure covers fixing and removal of formwork and
checking of formwork.
2. REFERENCE:
1. Approved Drawings
47
48. 2. IS 456 & IS 6461(Part 5)
3. Tender Document
METHOD STATEMENT FOR BOLTS PROCUREMENT & FIXATION
1. OBJECTIVE: This Procedure covers procuring and fixing of bolts.
2. REFERENCE:
1. Tender Specification
2. Approved Drawings
METHOD STATEMENT FOR CONCRETING WORKS
1. OBJECTIVE: This Procedure covers fixing and removal of formwork and
checking of formwork.
2. REFERENCE:
1. Tender Specification
2. Approved Drawings
3. IS 10262, IS 3370 & IS 456
4. IS 383
METHOD STATEMENT FOR BACKFILLING
1.OBJECTIVE: The scope of back-filling covers the filling in plinths, pits,
trends, depressions in layers 200mm thick including watering and compaction
by Roller / plate compactor.
2. REFERENCE:
1. Drawing
2. Bill of Quantities
METHOD FOR REINFORCEMENT WORK
1.All reinforcement shall be placed above the ground by using wooden sleepers or
concrete blocks.
2.For reinforcement, care shall be taken to protect the reinforcement from exposure to
saline atmosphere during storage, fabrication and use.
3.Against requirement from site, bars shall be cut and bent to shape and dimension as
shown in bar bending schedule based on Good For Construction (GFC) drawings.
48
49. 4.Reinforcement shall be tied as per the latest GFC drawing and any extra bars
provided at site shall be recorded in the pour card/ lap register.
5.Unusable cut rods and scrap reinforcement shall be properly placed at yard.
Bar Bending Schedule:
1.Prepare bar bending schedule based on the latest GFC drawings and to be submitted
to Engineer for review
2.Bar bending schedule shall clearly specify the following:
a) Bar dia.
b) Numbers.
c) Cut-lengths.
d) Shapes.
3.Bar bending schedule shall take into account the following field/ design
requirement.
a) Desirable lap locations and staggering of laps.
b) Lap lengths.
c) Development length/ Anchorage length.
Cutting, Bending and Placing:
1.All reinforcement shall be free from loose mill scales, loose rust and coats of paints,
oil, mud or any other substances which may destroy or reduce bond. Use wire brush
to clean the reinforcement.
2.Cutting and bending shall conform to the details given in the approved bar bending
schedule.
a) Cutting of Rebar by heat is not permitted, only cutting by grinding or shearing is
permitted.
b) No heating is allowed to facilitate bending of Rebar.
3.Place the reinforcement as per GFC drawings ensuring the following aspects
properly.
a) Type & size of bar. b) Number of bars.
c) Location and lengths of laps, splices.
d) Curtailment of bars.
e) In two way reinforcement, check the direction of reinforcement in various layers.
f) Adequate number of chairs, spacer bars and cover blocks.
49
50. g) Size of cover blocks.
h) All the bars shall be tied with double fold 18g soft GI annealed binding wire.
4.Reinforcement may be placed with in the following tolerance whenever required:
a) for effective depth 200mm or less ±10mm.
b) for effective depth more than 200mm ±15mm.
c) The cover shall in no case be reduced by more than one third of the specified cover
or 0 /+ 10mm.
d) The cover should suit various cover requirement as per Drawing Notes.
5.The sequence of reinforcement shall be correlated with fixing of inserts, sleeves,
conduits, anchors and formworks.
6.In walls, place accurately bent spacer bars wired to vertical or horizontal bars
between successive rows.
7.No steel parts of spacers sure allowed inside the concrete cover. Spacer blocks made
from cement, sand and small aggregate shall match the mix proportion of the
surrounding concrete. Alternatively PVC cover blocks of approved make can be used.
8.Spacers, cover blocks should be of concrete of same strength or PVC
9.Spacers, chairs and other supports detailed on drawings, together with such other
supports as may be necessaray, should be used to maintain the specified nominal
cover to the steel reinforcement.
10.Spacers or chairs should be placed at a maximum spacing of 1.0 mtr and closer
spacing may sometimes be necessary.
11.All reinforcement shall be placed and maintained in the positions shown in the
drawing by providing proper cover blocks, spacers, Supporting bars.
12.Rough handling, shock loading (Prior to embedment) and the dropping of
reinforcement from a height should be avoided. Reinforcement should be secured
against displacement.
METHOD FOR FORMWORK
Pre Check
1.Check if the shutters are properly cleaned by removing the concrete/ mortar and
protruding nails.
50
51. 2.Formwork shall be made to the exact dimensions within the permissible tolerances
as mentioned below.
3.Required thickness and quality of plywood conforming to IS 6461 shall be used to
meet the requirements of design and surface finish.
4.For beam bottom & sides, proper size of timber at required spacing shall be
provided to take the design loads/ pressure considering sleeves, conduit anchors &
inserts.
Erection of formwork
5.Sufficiently rigid and tight to prevent the loss of grout or mortar from the concrete.
6.Capable of providing concrete of the correct shape and surface finish within the
specified tolerance limits.
7.Soffits forms capable of imparting a camber if required.
8.The formwork may be of timber, plywood,steel,plastic or concrete depending upon
the type of finish specified.
9.Erect staging/shuttering as per drawing/sketches in such a way that deshuttering can
be done easily including provision for repropping, if planned.
10.Check the location, line,level,plumb and dimensions of the formwork to ensure
that the deviations are within the permissible limits.
11.Provide bracing at proper places & intervals as specified by the manufacturer or as
per formwork scheme to take care of lateral loads.
12.Apply mould oil/other coatings as release agents before reinforcement steel is
placed.
13.Wire ties passing through beams,columns and walls shall not be allowed .In their
place bolts passing through sleeves shall be used.For liquid retaining structures
,sleeves shall not be provided for through bolts.
14.Check all the shutters are properly aligned and fixed firmly with required lateral
supports and ties.
15.Check all the spanning members have proper bearing at the supports.
16.Wedges or jacks shall be secured in position after the final check of alignment.
17.Forms shall be thoroughly cleaned of all dirt, mortar and other matters such as
metals, blocks, saw dust and foreign materials before concreting if required through
clean-out openings.
18.Check all the gaps/openings are properly closed to avoid leakages.
51
52. 19.Check all the inserts/embedments and openings are exactly placed as per the
drawings.
20.In case of leakages, bulging and sagging immediate actions shall be taken by
tightening wedges or adjusting by jacks which must be done before the concrete takes
its initial set.
Removal of Forms
21.Formwork components shall not be dropped but shall be lowered without damage
to the components and structures. All the removed formwork materials shall be
thoroughly scarped, cleaned immediately and stacked properly for reuse.
22.'All forms shall be removed after the minimum period stipulated mentioned below
without damage to the concrete including removal without shock as per IS 456
METHOD FOR BACKFILLING
1. Backfilling area shall be free from foreign matters (ie. wooden scraps , plywood
pieces rebar bits etc) and tie rods recesses shall be rendered with polymer based non
shrink compound with a subsequent application of curing compound on them.
2.Filling around foundation or other places indicated shall be done with approved
material obtained from excavation or approved materials brought from out side.
3.The material shall be good quality soft or hard murrum or Panna sand or other
approved back filling material.Back filling soil shall be free from black cotton soil.
4.Filling shall be done in layers not exceeding 20 cms thick and each layer shall be
watered adequately and consolidated properly by rollers or pneumatic rammers 8 to
10 tonnes wherever conditions permit. If it is not possible, the consolidation shall be
done by hand rollers/ heavy pneumatic/ hand rammers/ plate compactor.
5.The surface of the filling shall be finished to lines and levels as required.
6.The approved materials shall be plced in layers, not exceeding 200mm in depth
before compaction and shall be compacted to minimum 95% dry density. Layers
placed in the top 300mm of the fill shall be compacted to 98% of maximum dry
density.
No of Samples:
(i)For foundation filling - one for every 10 foundation for each compacted layer.
(ii)For area filling one for every 1000 sqm area for each compacted layer.
52
53. METHOD FOR PILING
1.Excavate till the COL of pile
2.Predict the level of concrete in side the pile by driving rebar to touch the hard strata
of concrete.
3.Excavate till the predicted level of pile till visibility of concrete
4.Chip off loose concrete/ laitance from the top level of exposed concrete and ensure
the quality of concrete after chipping.
5.Straighten the distorted vertical bars & tie the lateral ties/ helical to COL
6.Fix the formwork of the required size up to the pile COL.
7.Apply the bonding agent(Nitobond EP) before pouring the concrete with the help of
an extended brush.
8.Pour concrete of the same grade(M30)
9.Strip the form work after 24 hrs
10.Back fill around the piles in layers not exceeding 200mm up to COL and allow for
PCC
11.FDT to be carried out as per relevent IS Code and Technical specification.
12.Curing of concrete with approved water shall start after completion of Initial
setting time of concrete and in hot weather after 4 hours. Concrete will be cured for a
minimum period of seven days when OPC with high water cement ratio is used,
curing for minimum 10 days in hot weather or low water cement ratio is used. Curing
shall be done by continous sprays or ponded water or continously saturated coverings
of sacking canvas,hessain or other absorbent material for the period of complete
hydration with a minimum of 7 days.Curing shall also be done by covering the
surface with an impermeable material such as Polyethlene ,which shall be well sealed
and fastened.
METHOD FOR CONCRETING
53
54. 1.Concrete mix design for Different Structure should be as per Notes in the specific
approved drawing
2.For Design Mix Concrete,the mix shall be designed to provide the grade of concrete
having the required strength, workability & durability requirements given in IS: 456
for each grade of concrete taking into account the type of cement, minimum cement
content and maximum W/C ratio conforming to exposure conditions as per tender
specifications.
3.Mix design and preliminary tests are not necessary for Nominal Mixconcrete (M5,
M7.5, M10, M15, M20 as Specified in IS 456 - Table 9) .However works tests shall
be carried out as per IS:456
4.No concreting shall be done without the approval of engineer. Prior notice shall be
given before start of concreting.
5. Cement shall be measured by weight in weigh batching machines of an approved
type, aggregate shall be measured by volume / weight. The machines shall be kept
clean and in good condition and shall be checked adjusted for accuracy at regular
intervals when required by the engineer. Material shall be weighed within 2.5%
tolerances, inclusive of scale and operating errors. The weigh batching machines /
Measuring Boes shall discharge efficiently so that no materials are retained.
6.Concrete shall be mixed in mechanical mixers of an approved type. In no case shall
the mixing of each batch of concrete continue for less than 2 minutes.The water to be
added in concrete 3.6 shall be adjusted based on moisture contents in fine and coarse
aggregates. During hot and cold weather, suitable methods to reduce the loss of water
by evaporation in hot weather and heat loss in cold weather will be adopted as per
procedure set out in IS: 7861.
7.The compaction of concrete will be done by immersion type needle vibrator which
shall be inserted into concrete in vertical position not more than 450 mm apart.
Vibration will be 3.7 applied systematically to cover all areas immediately after
placing concrete and will be stopped when the concrete flattens and takes up a
glistening appearance or rise of entrapped air
ceases or coarse agregate blends into the surface but does not completely disappear.
The vibrator shall be slowly withdrawn to ensure closing of the hole resulting from
insertion.
8.Unless otherwise approved, continuous concreting shall be done to the full thickness
of 3.8 foundation rafts, slabs, beams & similar members. For placing on slope,
54