guniting ppt

8/20/2019 guniting ppt

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VEERMATA JIJABAI TECHNOLOGICAL

INSTITUTE

CIVIL AND ENVIRONMENTAL ENGINEERINGDEPARTMENT

REHABILITATION OF STRUCTURES


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ANIKET PAWAR

(152030010)

GUNITING


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The term "gunite" refers to a dry-mix process. It was invented in 1909 by naturalist arl !eley.

It involves a mixture of #ortland cement and sand thoroughly

mixed dry$ passed through a cement gun and conveyed by air

through a flexible tube. There are two different processes in use namely %wet mix& and

%dry mix&.

'ormally fresh material with (ero slump can support itself

without sagging or pilling off. There is not much difference between guniting and shotcreting.

The dry mix process is more successful and is generally used.

INTRODUCTION


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)unite can be defined as mortar conveyed through a hose

and pneumatically pro*ected at a high velocity on to asurface.

DEFINITION


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1. ement and sand are thoroughly mixed.

+. The cement-sand mix is fed to special air pressuri(ed mechanical feeder termed as

,gun.

. The mixture is metered into the hose by a feed wheel or distributor within the gun.

/. The material is carried to the no((le by compressed air through delivery hose.

. The no((le is fitted inside with a perforated manifold through which water is sprayed

under pressure and intimately mixed with the sand-cement *et.

. The wet mortar is *etted from the no((le at high velocity onto the surface to be

gunited.

PROCESS OF DRY MI


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DRY MIX PROCESSDIAGRAM


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GUNITING MACHINE


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• It enables to have extremely strong 2 dense concrete.

• oncrete produced thus is highly resistant to

weathering 2 chemical attac.• It is also heat resistant to a high degree.

• Its resistance to abrasion is extremely high.

• 3ore homogeneous and waterproof concrete is

obtained.

PROPERTIES OF GUNITE


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It can be impacted on to any type of shape of surface including vertical oroverhead areas.

It adheres better than poured concrete to the structural steel.

It is used when formwork is cost prohibitive, impractical, where form can

be eliminated and normal casting techniques cannot be applied.

The high compressive strength is obtained. Strength of about 5 to !"

n#mm$ at $% days is generally obtained.

The repairs are carried out in any situation in a short time.

It will be placed and consolidated at the same time.

It o&ers reduced shrinkage and lower permeability.

ADVANTAGES OF GUNITING


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SR.

NO.

SHOTCRETE GUNITE

1It covers both dry and wet mix

process of shotcreting.

It is the dry mix process of

shotcreting.

2

It is a method in which fine concrete

is deposited by *etting it with high

velocity.

It is a method in which fine mortar

is deposited by *etting it with high

velocity.

3 4i(e of aggregates used is between10 to 1+ mm.

4i(e of aggregates used is below 10mm.

!5astage of material is less as

compared to guniting.

omparatively more wastage of

material is there.

54illed no((le man may or may not

be re6uired here.4illed no((le man is re6uired here.

"7oth smaller and larger thicness is

achieved.

omparatively smaller thicness is

achieved.

#5ater cement ratio is between0. to

0..5ater cement ratio is 0..

$!dmixtures are added near to the

no((le.!dmixtures are added to feeder.

%5ater cement ratio may or may not

be ad*usted.

5ater cement ratio can be ad*usted at

the time of placement.

DIFFERENCE BETWEEN SHOTCRETE ANDGUNITE


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Repair of ra!" i# $a%

APPLICATIONS OF GUNITING


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Gi'i#( for "pi))*a+


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Gi'i#( for ,re $a%a(e$ "'r&'&re


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Repair of orro$e$ pi)e" -+ (i'i#(


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Co#re'i#( of o%p)e "/ape"


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Gi'i#( for &r0e$ "&rfae"


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Gi'i#( &"e$ for a#a)1)i#i#(


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Gi'i#( &"e$ for o#re'i#( of $o%e1"/ape$ "'r&'&re" */ere for%*or!

ere'io# i" #o' po""i-)e


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Gi'i#( $o#e for "*i%%i#( poo)"


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Gi'i#( $o#e for "*i%%i#( poo)"20i$eo3


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GUNITING20i$eo3


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Gi'i#( &"e$ for '#e)1)i#i#(


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THAN41YOU

guniting ppt

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