Quality Controls - Odishapanchayat.gov.in

siennatearfulUrban and Civil

Nov 25, 2013 (4 years and 1 month ago)

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1

Ensuring Quality in civil Construction


Presented by :


Er. P. Das,(M.Tech.Civil )A.E, Jatni.

Under the guidance of


Er. Mahendra Kumar Mohanty


EE,DRDA,KHORDA

2

Definition of Quality


Quality means excellence.




It is thus a philosophy rather than a mere attribute.



The difference between two objects

is judged by their qualities
.



We set some standards which

determine the level of acceptability
.

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Quality control:
-




Quality control means rational use of resources.



Quality control procedures implement:
-



appropriate mixing,



proper compaction,



correct placement and



adequate curing.



Quality control prevents temptation of over

design.


4


Quality Controls
-----




Quality control ensures:
-




strict monitoring of every stage of


concrete production and




rectification of faults.



Quality control reduces maintenance

costs
.


5

Plan, Do, Check and Act cycle
for assuring quality

6

Plan
:
-
quality


Do

:
-

Working
systematically


Check:
-

checking with

non
conformance



Act :
-
Upon
the result




The
cement sand mix
in the mortar and brick

masonry
is made quite early
, prior

to its use

and
in larger

quantities
than required.



The
construction materials
like sand, bricks,



Aggregate
etc
are not washed
and are
full of



deleterious material and dust
.



7


Knowing the 20 No mistakes
occurr during
construction phase
( for planning purpose )

construction mistakes


Compaction

of bottom strata in foundation

work is not carried out.


During concreting of footing, the
concrete is
poured

at a height greater than 1m.



Generally,
trapezoidal footings
are resorted
to where

concrete
is
never vibrated.


8

construction mistakes


Reinforced concrete
column
, being an
important part of the structure are neither
mechanically vibrated nor machine mixed
.



They are
cast in short lifts
with increased
number of joints.


Cover

to reinforcement in column, beams
and slabs is
insufficient.


9

construction mistakes


No

cover

to

reinforcement

in

contact

of

the

ground


Misalignment

of

column

at

foundation

level

and

rectification

at

higher

level,

leading

to

eccentric

loading
.





Reinforced

coping

at

plinth

level

being

an

important

barrier

to

dampness

is

never

densely

cast
.


10



The

plinth

filling

is

never

carried

out

in

layers

nor

compacted
.



At

the

joints

of

Reinforced

concrete

and

brick

masonry,

either

:
-



the

RC

surface

is

not

roughned


or

filling

of

mortar

at

the

joint

is

not

evident
.



11

construction mistakes



The

joint

of

brick

masonry

at

larger

height

are


improperly

racked
.





Mixing

ratio

in

plaster

and

brick

masonry

is

not

maintained
.


12

construction mistakes



In

the

case

where

beams

are

cast

prior

to

slabs

:



In

large

slabs,

the

concrete

in

beams

starts

setting

before

casting

of

RC

slab
.



The

concrete

spilled

on

the

sides

of

beams

while

casting

is

never

removed

which

gets

set

subsequently


13

construction mistakes


Reinforcement

of RC
column

is kept
exposed

above RC slab.




Hacking

to concrete surface is poorly
done
prior to Plastering.



Bearing to lintels
on both the ends is
not

sufficient.



14

construction mistakes


In load bearing structure ,
secondary beams
are
resting
directly
on the walls
giving point
loading.



Proper
care

for uplift pressure
in black
cotton

soil is not taken
in by
proving with



ground beam


Combined footing



15

construction mistakes

The above 20 no construction mistakes may result
in



Cracks in concrete.


Improper bonding between concrete and
brick masonry
.


Spillage of plaster.


Dampness of walls.


Leakage of slabs.


Cracks in brick masonry.


Settlement of foundation and walls.





Result of mistakes.

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Causes for poor quality can be summarized
as

ignorance,
poor materials
,
poor design
,
poor detailing
,
poor workmanship
,
improper

quantity of cement
,
improper concrete mix,
excess water,
inadequate compaction
,
substandard forms
, inadequate curing
,
inadequate cover
, poor construction
practices,
poor supervision
and above all
lack of technical knowledge
.

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Causes of mistakes

19

Description of
deficiency
Frquency of
occurrence
Applicable
application
% frequency
occurrence
Inadequate
suspended
reinf conc beam
depth
6
13
46%
missing column
reinf
1
17
6%
retaining wall
reinf on wrong
side of wall
11
1
100%
inadequate
cantilever reinf
anchorage
1
1
100%
Effectiveness of the Existing system in quality
vulnerability reduction

20

Entity
Block Development Officer
Assistant Engineer
JE
Executive Officer
Executant
Sanjojaka
only interested in profit as 10%, profit is not in estimate
Can't be believed,not accountable
Comments
Check only the progress
Monitor progress,Check quality,encourage public participation
Estimate,Execute,Check only during his presence
Does not Check quality
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With the
increase of
quality of
design, cost
increase

is
exponential but
value addition
initially
increases, but
starts saturating
at of some point
.
Hence the
optimum cost is
arrived when
slope of both the
curves is same
.

Relation between Quality and Cost

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One can note
that with the
increase of
quality of
construction,
cost of quality
control gets
saturated.
Thus we can
arrive at
optimum
quality for
minimum cost
from total cost
of the
construction.

Economics of Quality of
Conformance










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Case Study



Project : Community
Centre

Scheme : MPLAD

GP: Gangapada

Est.Cost :
-
3.96 Lakh

Steps taken
:
The
entire reinforcement
was wrong, and was
removed as per the
design requirement

Of the slab













CONCLUSIONS:

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100% quality in PR Deptt. can not be
controlled it can only be managed by :
-


Immediate Execution of the work



Use of machinery and technology



Experienced quality engineer



Distributing quality manuals to the

people


More no of supervision to the site

Thank you

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