Akash

WELCOME

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Ensuring Quality in civil Construction

Presented by :

AKASH MANDAL

10/FET/C(S)/2006

99999-2-4321.Under the guidance of

ER. AKASH

CIVIL ENGINEER2

Definition of QualityQuality 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.

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Quality Controls-----

Quality control ensures:- strict monitoring of every stage of

concrete production and rectification of faults. Quality control reduces maintenance

costs.

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Plan, Do, Check and Act cycle for assuring quality

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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.

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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.

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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.

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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.

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construction mistakes

The joint of brick masonry at larger height are improperly racked.

Mixing ratio in plaster and brick masonry is not maintained.

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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

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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.

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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

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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

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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

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Entity

Block Development Offi cer

Assistant Engineer

JE

Executive Offi cer

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

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 peopleMore no. of supervision to the site