Section Active Str. Sys - Slabs

8/17/2019 Section Active Str. Sys - Slabs

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BUILDING CONTRUCTION

TECHNIQUES

SUBMITTED BY –

MANI ARORA


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The simplest way of describing the function of structure is to say that it is the part of a building which

resists the loads that are imposed on it. building may be regarded as simply an envelope which encloses

and subdivides space in order to create a protected environment. The surfaces which form the envelope,

that is the walls, the floors and the roof of the building, are subjected to various types of loads.

Gravitational loads and the occupation of the building cause roof and floor structures to bend and

induce compressive internal forces in walls. Wind causes pressure and suction loads to act on all

external surfaces.

The relationship of

structure to building

external surfaces are exposed to the

climatic loads.floors are subjected to the gravitational loads

of the occupants and their effects


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A building structure must be able to support two types of

load.

1. Static load. 2. Dynamic load.

Static load: ssumed to be constant in nature. !ts two type.

1.Dead load 2.Live load

Dead load:

"ead loads are relatively fixed and include the weight of the

building structure itself as well as the weight of any

permanent elements with in the building such as mechanical

e#uipment.

Live load:

$ive loads are moveable loads which may not be present all

of the time . They include the weight of a building occupants

and , furnishing as well as show loads no roof.

Dynamic load:%an be applied to a structure suddenly and vary in magnitude

and location.

The relationship of

structure to building

"ynamic load


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03

Structural requirements

To perform its function of supporting a building in response to whatever loads may be applied to it, a structure

must possess four properties&

it must be capable of achieving a state of

equilibrium.

This re#uires that the internal configuration of thestructure together with the means by which it is

connected to its foundations must be such that all

applied loads are balanced exactly by reactions

generated at its foundations.

it must be geometrically stable.Geometric stability is the property which

preserves the geometry of a structure andallows its elements to act together to resist

load. The distinction between stability and

e#uilibrium is illustrated by the framewor'

it must have ade#uate strength.The re#uirement for ade#uate strength is

satisfied by ensuring that the levels of stress

which occur in the various elements of a

structure, when the pea' loads are applied, are

within acceptable limits.

it must have adequate rigidity.(tructural calculations allow the

and rigidity of structures to be controlled

precisely. They are preceded by an

assessment

of the load which a structure will be re#uired

to carry.


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03

Basic structural elements

Slabs:

(labs generally refer to various types of floor

systems designed to support floor and sometimes

roof

loads.

alls! Load Bearing:(tructural walls are the vertical

constructions of a building that enclose a

building. (tructural

walls may also be internal partitions used

for load)bearing conditions forming part of

the

structural framing system. There are two

types of load bearing slab.Load bearing wall

slab

One WaySlab

Two WaySlab

Wafe Slab

MAIN BAR

DISTRIBUTION BAR


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Beam:*eams are typically hori+ontal structural

members designed to carry a load. (teel is

one of the

most common materials used for beams,

since it can withstand very heavy loads.

"olumn:

re upright vertical structural members thatsupport

slabs, beams or trusses

10


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03

!n strictly technical terms , structure may be considered as the means of translating external force into internal

loads caring mechanism in order to support and reinforce an rchitectural concept.

There are basic three types of structural system

.

Section Active Structural system:

.-ost slab structural system.

2.-ost)lintel structural system

1.Wall slab structural system.

(lab


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03

ALL SLAB

%ontinuous or linear support system to transfer the external loads to the ground with the help of wall and

slab. load bearing wall is a wall that bears a load resting upon it by conducting its weight to a foundation

structure.

Structural #ember

i. Wall vertical load bearing member /

0. Cellular wall arrangemen !

ALL SLAB ST$%"T%$AL S&ST'#

ertical load bearing member

The structure consists of walls each joined to its neighbor. The external walls

form the boundaries of the building and the internal walls divide the building

into cells rooms/ ma'ing the building cellular.

Non load bearing wall

Load bearing wall


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ii. (lab hori+ontal load bearing member /(lab

0 ne way slab

0 Two way slab

0 Waffle

3or Large Span waffle slab constructed

Length ( width )*+ 4one way slab

Length ( width ,*+4two way slab

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5xample

"ost and time

0 $ow rise building 6this system represents economy0 Generally low cost construction

0 3oundation 6more shallow than other system0 %onstruction period 6larger than any other system

-ormal 'pression

0 -lan 6no grid pattern, can be any desired shape0 $arge ,unbro'en plans could be expressed0 !n elevation 6 small punches0 3or large openings ,arches are provided

0 7assive and bold0 rch, dome, and vaults can be constructed in this

type of structure0 %antilevers can expressed as planes0 (olid void relation is boldly represented0 3or hot dry climate this type of structure gives

extra benefit.0 (creen wall can be added

0 This type of structure lasted for thousand years.

/eight 0 Generally 8 storied

Twin "ouse# C"arles Correa

Banglades" $ye %os&ial # Louis I

'a"n

(irs Uniarian C"ur)" # Louis I'a"n


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reng" 3or low storied structures this system is economical. 3oundation is shallower than other systems, so

foundation cost is the least of all. This type of construction lasted for thousands of

years. The construction of 7ohenjo)"aro built about

29:: *.% can be still identified

rches, "omes and aults are used in this system. -ost does not disturb the free space.

Wea*ness (pan of the area is not enough. 7aximum 12;. $imitation of structure height 8)< storied. Walls must be built over a wall. 7ore time is re#uired

(mall space over a big space is not possible. %ontinuous opening can not possible

&&oruniy (creen wall can be used. =atural color can be obtained in the building surface, by

different exposed bric' of different hue. 3or hot dry climate this type of structure gives extra benefit. Wall thic'ness sometimes is extra beneficial for shading. This system could expresses the composition of >ori+ontal

and vertical plane.

T"rea This type of construction is not possible with out

good load bearing capacity of earth. 3lexibility of massing is very small floors can

taper ? up)ward. "ampness is also greater problem.

all slab structural system


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0ost lintel!n rchitecture post and lintel structural system is a simple constructiontechni#ue also called column and beam,hori+ontal member is supported by two vertical posts at either end. ll structural opening have evolved from this.

-ost)and)beam structures are either load bearing wall structures or framestructures. large range of spans is also possible depending on the types of

element which are used.

+ar"enon# ,R$$'

%$@7=

*57(


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03

L1AD B'A$234 S&ST'# 1- 01ST L23T'L

Load Dead load and Li-e load

Linel

Columns

(ooings

,round

7ultiple rectangular grid(ingle rectangular grid7ultiple s#uare grid

(ingle s#uare grid


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!f $ength A $ Width A W, ? $BW C 2

Then the slab wor's as a one way slab

ne way slabTwo way slab

1rientation of members

D5%T=G@$D -$= D"!$ GD!" 3or %olumn3or *eam


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1. n overhang where one floor extends

beyond and over a foundation wall.

2. %an be possible even more than :)9:E

economic/

. (pan is limited,1


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0ost Lintel Structure System

9:E cantilever system is applicable. @nexpected beam hampers interior. coustic problem may occur. (tairs must be started with the reference of beam

& 7aximum column to column opening ny type of roof can be provided esthetic framewor' can be done

!f beam is not strong enough, where large span,

huge concentrated load may occur bending stress

and deflection.

(hort span beams with large concentrated loadnear the posts will occur shear stress .

reng" Wea*ness

&&oruniy T"rea


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0ost slab structural system:

#embers: %olumn , (lab

(lab >ori+ontal structural member

-ost ertical structural member

"lassification of post slab:

. flat plate

*. flat slab & with capital

with drop

with capital ? drop

/a &lae &os slab /a slab wi" )a&ial /a slab wi" dro& /a slab wi" )a&ial 0 dro&


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#aterials:D . % . % , iron

Load transfer system:

The load of the slab it self and other live load transfer to the post by the slab. both

the dead load and live load which the post gets form the slab transfer to the ground

by the post.

$oad slab column ground1 1 1

slab

&os

,.L.

2ooing

L

Middle sri&

Column

sri&

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-lat

slab-lat slab with drop

panels

-lat slab with column head -lat slab with drop panel and column head


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Wall can be built freely as desired in different floors.

it is recommended to built walls on the column strips

!t is better to avoid the middle strips from first floor

0osition of wall!

Hohnson Wax dministration *uilding

3ran' $oyd Wright

7D3 >ead#uarter

%harles %orrea

06

37


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'pression:

The plan of the building of post and slab system is regular shaped and

respect strong s#uare grid pattern.

The slab is always cantilevered from the post.

(olid void relationship is strongly achieved

ertical reference is maintained


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7assing constructed in post and slab system has an effect of floating

%ontinuous opening can be provided

'pression:

Advantage:

Dibbon window or large opening is a greater opportunity

%antilever E9:E possible

(labs can be cut as freely as needed

-osition of enclosing wall can be changed in different floor plan "ifferent types of shading device can be used

-artition wall can be use as re#uired


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illa savoya

$e corbusier

'ample:!

06


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Load transfer system:

slabBfloor

%olumn

3ooting

sub soil


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1rientation&

(#uare grid pattern


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1pening&

%ontinuous opening, ribbon window

"antilever :


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0unch in slab&

$arge -unch, without disturbance of beam


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03

reng" 5conomical for low storied structure (hallow 3oundation $ong lasting

Wea*ness %ontinuous ribbon window for panoramic view

is impossible. Wall thic'ness is greater than in the other two

systems.

s for the poor opening ratio, it is not suitablefor our climatic condition.

(mall space over a big space is not possible. Wall must be built over a wall.

&&oruniy

-lans follow no grid patternI it can be of any desired shape. $arge, unbro'en plans could be formed. 5xtra benefit for hot dry climate Wall thic'ness sometimes extra beneficial for shading. -ost does not disturb the free space.

T"rea =ot usually suitable for high)rise (pan of the area is not large enough. llowable amount of cantilever is limited $ow 3lexibility of massing

0ost slab structural system

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0 waffle slab is a two)way concrete slab

reinforced by ribs in two directions.

0 Waffle slabs are able to carry heavier loads

and span longer distances than flat slab.

0 ;; to F)1B2;;


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Documents

Section Active Str. Sys - Slabs