Floor System in Multistory Building
Transcript of Floor System in Multistory Building
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FLOOR SYSTEM INMULTISTORY BUILDING
Floor Structural Subsystem
Floor Finish Subsystem
Ceiling (Soffit of floor) finish subsystem.
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FLOOR STRUCTURAL SUB SYSTEM
Vertical Loading Function
The main function of the floor structural system is to carry
the live loads and dead loads that are placed on it. Thenthe floor structure has to transfer these loads to eithersupport beams of the structural frame or supportingstructural walls. The floor structure must be stiff enoughas to neither noticeable deflect due to the load nor felt tooscillate when repetitive impact loads (e.g people
walking) are applied.
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Horizontal Loading Function
Act as internal strut of the buildings horizontal loadingstructural system.
Deeper solid floor slabs or joists or girders give betterstiffness to the building
Yet to compensate for the deeper floor slab or girders orjoist, designers will increase the floor-to-ceiling height.
The impact is more expense due to longer ducts, liftshafts, increased materials etc.
On the other hand, if the designer does not increase thefloor to ceiling height, the headroom will be limited andthe use of false ceilings and floors to house the servicesruns is restricted.
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TYPES OF FLOOR
SteelFloorConcreteFloor
Composite steel-concrete
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ADVANTAGES OF COMPOSITE STEEL-
CONCRETE CONSTRUCTION
1. Combination of the advantages of steel withadvantages of concrete
2. Reduced temporary works
3. Reduced wet construction operations
4. Improved usable floor height
space
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Light-weight or normal concrete floorstructures
ONE WAY SYSTEM
TWO WAY SYSTEM
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1. Cast in situ solid Slab
2. Slab on Joist Floors
3. Pre-cast concrete slab
4. Post-tensioned joist supporting precast concrete slab or in situ
concrete slabs.
ONE WAY SYSTEM
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Two way slabs on stiff beams
Two way slabs on shallow joist
bands Flat slabs
Waffle slabs
Pre-cast slabs Diagrid floors
TWO WAY SYSTEM
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Steel Floor Structures
Two classes of steel floor structures
NON COMPOSITE FLOORINTERACTION
COMPOSITE FLOORINTERACTION
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The floor r.c slab can act separately from steelframework. In other words, the steel and concretecomponents of the floor act as separate structural
entities.
NON COMPOSITE FLOOR
INTERACTION
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The floor slab can act in composite way withsteel framework. In other words, the steel and
concrete are keyed to each other and interact as asingle element instead of two separate
components
COMPOSITE FLOOR
INTERACTION
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STEEL FLOOR CONSISTS OF 2COMPONENTS
FLOOR SLAB
HORIZONTAL SPANMEMBERS
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SKIN SYSTEM
CAST IN SITU
CONCRETE
SLAB
CAST IN SITU CONCRETE
SLAB ON CORRUGATED
METAL DECK WITH ANCHOR
STUD
CAST IN SITU
CONCRETE SLAB
ON CORRUGATED
METAL DECK
PRE CAST
CONCRETE
SLAB
CERAMIC
SLAB
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HORIZONTALSPAN MEMBERS
OPEN
WEBBEB
STEEL JOIST
CASTELLATED HOT
ROLLED BEAM
TRUST GIRDERS
LATTICE
GIRDERS
HOT ROLLED
BEAM
VIERENDEEL
GIRDERS
STUB
GIRDERS
TAPPERED OR
HAUNCHED
GIRDERS
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NON COMPOSITE STEEL FLOOR
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COMPOSITE STEEL FLOOR WHERE
STEEL I BEAM IS EMBEDDED IN
CONCRETE
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COMPOSITE STEEL FLOOR USING
METAL DECKING
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TYPES OF COMPOSITE STEEL
FLOORS
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Fire Protection
Contact fire proofing
The steel frame may be fireproofed by eitherencased in a fireproof material such as
concrete or sprayed with contact fire proofingmaterials e.g vermiculite If steel decking is partof the floor system, the soffit of the decking isspayed with contact fire proofing materials e.g
vermiculite
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Ceiling as membrane fire fighting
The ceiling behaves as a fire resistance barrier.
It protects the floor structure and theM&E ducts, pipes and cabling within the ceiling
space fr. the floor below. To prevent fire spreadthrough the ceiling space, fire curtains are
installed in the ceiling space to fire-compartmentalise the space
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Accommodation of Services
1. Below the floorThe horizontal M&E pipes and ducts are suspendedeither from the floor frame or from the soffit in thesuspended ceiling space.
2. Within the floorThe M&E pipes and ducts are directly supported bythe floor either through the penetrations in the floorcomponents e.g. holes through beams, trussesgirders or imbedded in the concrete slab or in chasesin the floor slab.
3. Above the floorThe M&E pipes and ducts are directly supported onthe floor in the space created by raised floors.
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FLOOR FINISH SUBSYSTEMS
Screed floorThe floor finish is usually screed which is laid on theconcrete slab. Tiling or membrane type covers (e.g.carpet, linoleum) are laid on the screed. Access boxesfor the M&E ducts lain in the floor slab are positioned
relevant to the layout of the floor.
Raised floorPropriety raised floor systems are installed onto the floorcreating a false floor. Space within the raised flooraccommodate M&E ducts, cables etc and allows theused of under-floor air-conditioning plenums.Manufacturing have devised raised floor systems thatmodular and integrated for accomodating airconditioning, electricity and telecommunication serviceslines.
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Ceiling Subsystems
Wet construction
- Plaster or spray finish orcemented acoustic tilingthat are clad directly to
the floor soffit.
- May also be in the form orwet plastering on dryboards on a frame that iseither suspended from thefloor soffit or fixed
directly to the floor soffit
- Usually for residentialbuilding
Dry construction
- Dry boards or tilesfastened on a frameeither suspended from the
floor soffit or fixeddirectly to the floor soffit.
- Made from gypsum, metallath, wood cement etc.Tiles are usually of theacoustic type.
- Ceiling are either attacheddirectly to the floor orsuspended with hangingwires or rods from thefloor.
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Suspended ceilings
SOLID TYPE
GRID TILETYPE
LINEARPLANKING
TYPE
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CONSTRUCTION OF SUSPENDED
CEILING
Assembly of separate parts installed by varioustradesmen. The parts are standard design componentsand may be sourced from different manufacturers.However the dimensions of the light, air-conditioning andfire safety fittings are usually aesthetically incompatible
with the ceiling Assembly of a complete propriety system from a single
manufacturer. Such a ceiling is called an integratedceiling. An integrated ceiling is either of the linear planktype or the grid tile type. The ceiling system consists ofthe following components.
- ceiling support system- ceiling materials for acoustic and fire protection
- light fittings
- HVAC air diffuser