BUILDING SUPERSTRUCTURE
Oct 26, 2014
BUILDING
SUPERSTRUCTURE
LEARNING OUTCOMES
At the end of the class, students should
be able to:
Identify types of superstructures
Determine the properties of each types
of superstructures
Understand the construction method of
each types of superstructures
MAIN TOPIC
BUILDING
SUPERSTRUCTURE
COLUMN
FLOOR
ROOF
WALL
ROOF
WALL
BEAM
COLUMN
A column in structural engineering is a vertical structural element that transmits, through compression, the weight of the structure above to other structural elements below.
Columns are frequently used to support beams or arches on which the upper parts of walls or ceilings rest.
COLUMN EVOLUTION
National Capitol
Columns at the United
States National
Arboretum in
Washington, D.C.
Mosque of Uqba, city
of Kairouan, Tunisia
In architecture "column" refers to such a
structural element that also has certain
proportional and decorative features.
Early columns were constructed of stone, some out of a single piece of stone, usually by turning on a lathe-like apparatus.
Single-piece columns are among the heaviest stones used in architecture
Modern columns are constructed out of steel, poured or precast concrete, or brick.
They may then be clad in an architectural covering (or veneer), or left bare.
BEAM
BEAM Beam are rigid structural members
designed to carry and transfer transverse loads across space to supporting elements.
A beam is a structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight and external reactions to these loads is called a bending moment.
Beams generally carry vertical gravitational forces but can also be used to carry horizontal loads (i.e., loads due to an earthquake or wind). The loads carried by a beam are transferred to columns, walls, or girders, which then transfer the force to adjacent structural compression members.
Beams are characterized by their profile (the shape of their cross-section), length and material. In contemporary construction, beams are typically made of steel, reinforced concrete, or wood.
One of the most common types of steel beam is the I-beam or wide-flange beam (also known as a "universal beam" or, for stouter sections, a "universal column").
This is commonly used in steel-frame buildings and bridges. Other common beam profiles are the C-channel, the hollow structural section beam, the pipe, and the angle.
FLOOR
FLOOR
In architecture, a floor is generally the
lower horizontal surface of a room, and/or
the supporting structure underneath it.
A floor typically consists of a support
structure called a sub-floor on top of
which is laid a floor covering to provide a
walking surface.
The work of installing a floor covering is
called flooring. This term is also used to
refer to any permanent floor covering and
in particular to wood flooring.
The two major forms of floor construction
are 'suspended' and 'solid'. Suspended
floors are usually made out of quality or
economical timber boards or waterproof
chipboard sheets fixed on top of joists
Functional requirements
The main function is to provide support for the occupants, furniture and equipment of building.
These may be defined as the provision of adequate:
Strength and stability
Fire resistance
Sound insulation
Thermal insulation
Damp insulation
TYPES OF
FLOOR STRUCTURE
SOLID FLOOR
SUSPENDED FLOOF
STEEL FLOOR
TIMBER FLOOR
CONCRETE FLOOR
Solid floor
Plain or reinforced concrete.
In most building without basements the ground floors are solid of construction, of concrete on hardcore resting directly on the ground.
The thickness of the slab will vary according to the loading which the floor is to carry and the bearing capacity of the ground.
Suspended floor
These may be constructed in timber,
reinforced concrete or steel and, as in the
case of roof construction may be in the
form of single, double or triple construction
according to the loads and spans involved.
Timber floor
The timber floor has the advantages of
light self-weight and of being a dry form of
construction.
It is simple to construct and this, together
with the saving effected in the supporting
structure because of its light weight, make
it economical particularly where the
imposed loads are small.
Concrete floor
The concrete floor has the advantage of
strength and good fire resistance.
Its use in most of form of multi-storey building,
particularly because of the requirements in
respect of fire resistance which apply to such
structures.
The choice of a concrete floor can be made from
a wide variety of types including in situ solid
concrete floors, in situ hollow block floors and
pre cast floors of numerous forms.
ROOF
Terminology Roof: the entire covering assembly
Roofing: that part of the roof which is exposed to the elements.
Pitch: rise over run
Substrate: the decking that carries the roofing material.
Eaves: roof overhangs
Ridge: the peak of two or more roof slopes
Valley: an inverse ridge
Ceiling: the finish material attached to the underside of the roof
Basic types of roof designs:
Flat: must have a slight slope for drainage
Shed: a single slope
Gable: two slopes meeting at a ridge. Two walls extend up to the ridge.
Hip: two gables, a pyramid could be considered a hip roof.
Gambrel: four slopes in one direction, the typical barn roof.
Mansard: two gambrels. Basically is to the gambrel what the hip is to gable.
Flat
Shed
Gable
Hip
Gambrel
Mansard
Gable Roof
Shed Roof
Mansard Roof
Gambrel Roof
Hipped Roof
Pitched roof design:
A roof is designated as pitch if its slope is
more than ten degrees.
In areas of heavy rainfall a steeply pitched
roof quickly throws off rain, while in areas
oh heavy snowfall a less steeply pitch roof,
not more than 35-40 degrees, preserves a
useful ‘insulating blanket’ of snow during
the cold season, but permits the water to
run off freely.
Flat roof design
A roof is designated as flat if its slope is
less than ten degrees
Flat roofs have traditionally been used in
hot climates where water accumulation is
not a problem
They were generally unkown in northern
climated before the end of the last century.
Advantages of flat roof design
No space lost below roof, i.e. no dead space.
Less material is used than in a sloped roof.
The rooftop is potentially useful as a terrace, or sleeping porch.
Potentially pleasing appearance.
Easier to build than a sloped roof
Disadvantages of flat roof design
Roof elements can not overlap, hence
waterproofing must be more complex, and
more thorough
Drainage is not automatic
Support of snow load must be insured
Weatherproofing the flat roof
The flat roof relied on some kind of
membrane for keeping moisture out. In dry
climates this is done with clay tiles, but in
Canada asphalt, or rubber is necessary.
Flat roofs are never actually flat, a subtle
slope directs standing moisture to drains
at edges, or inside
Polyurethane coating
Roof waterproofing film
Flashing Flashing is special material used to make
sure that no moisture leaks in those areas of a roof that are particularly vulnerable to penetration. Areas where flashing is commonly used:
Wherever the roof is pierced by a chimney, skylight, air or plumbing vent
Where roofs meet walls
At the edges of flat roofs where they meet parapet walls (a wall that extends above the level of the roof)
Insulation
Because hot air rises, roofs lose more
heat than walls, and thus require greater
degree of insulation.
There is a multitude of different locations
for the insulation in a roof, some of which
are listed here.
Sloped roofs insulation location
Resting above ceiling
Attached between rafters
Between the substrate and the roofing (a
particularly useful method of the rafters
are to be exposed, but may result in
overheating in the summer)
Flat roofs insulation location
Between substrate and roofing
Resting above roofing material (with
ballast provided to keep it from moving)
Factors to be considered
FACTORS
TO BE
CONSIDERED
WEATHER RESISTANCE
THERMAL INSULATION
FIRE RESISTANCE
SOUND INSULATION
Weather Resistance
Adequate weather resistance is provided
by the roof coverings and the nature of
these will affect the form of some details of
the roof structure.
Thermal Insulation
Is rarely a factor affecting the choice of the
roof type since the normal methods of
providing it are generally applicable to all
form of roof.
Fire Resistance
The degrees of fire resistance which a roof
should provide depends upon the proximity
of other building which the roof cover.
Adequate fire resistance is necessary in
order to give protection against the spread
of fire from and to any adjacent buildings
and to prevent early collapse of the roof.
Sound Insulation
Most form of roof construction provide for
the insulation of building an adequate
degree of insulation against sound from
external sources.
Only in the case of building such as
concert halls in noisy localities might
special precautions be necessary and only
in such cases it is likely to be a factor
affecting the choice and design of the roof
structure
Roof drainage
R.C gutter
Scupper drain
WALL
The vertical constructions of a building that enclosed, separate, and protect its interior spaces.
It is consist of:
1) Load bearing wall
2) Composite wall
3) Non-load bearing wall
A wall is a usually solid structure that defines and sometimes protects an area.
Most commonly, a wall delineates a building and supports its superstructure, separates space in buildings into rooms, or protects or delineates a space in the open air.
There are three principal types of structural walls: building walls, exterior boundary walls, and retaining walls.
In addition to support vertical loads, exterior wall constructions must be able to withstand horizontal wind loading.
If rigid enough, they can serve as shear walls and transfer lateral wind and seismic forces to the ground foundation.
The wall construction should control the passage of heat, infiltrating air, sound, moisture and water vapour, durable and resistant to the weathering effects.
Internal Wall
The interior walls or partitions, which subdivide the space within a building, may be either structural or non load bearing.
be able to support the desired finish materials, provide the required degree of acoustical separation, and accommodate the distribution and outlets of mechanical and electrical services.
The primary function is to act as a vertical divider of floor space and in so doing form a storey height enclosing element.
Opening for doors and windows must be constructed so that any vertical loads from above are distributed around the openings and not transferred to the doors and windows.
The size and location are determined by the requirements for natural light, ventilation, view and physical access
Load Bearing Wall A load-bearing wall or bearing wall, is one in which a wall
of a structure bears the weight and force resting upon it, conducting the vertical load from the upper structure to the foundation.
It gives a building structural integrity.
It carries and distributes weight from the roof and top floors down to the foundation.
Damage to a load bearing wall can cause floors to sag, finishes to crack and the entire structure to collapse
The materials most often used to construct load-bearing walls in large buildings are concrete, block, or brick.
Application of Load Bearing Wall
Depending on the type of building and the number of stories, load-bearing walls are gauged to the appropriate thickness to carry the weight above it. Without doing so, it is possible that an outer wall could become unstable if the load exceeds the strength of the material used, potentially leading to the collapse of the structure.
Notre Dame de Paris
flying buttress
Non-Load Bearing Wall
A wall capable only of supporting its own
weight and (if it is an exterior wall) capable
of resisting the force of the wind blowing
against it; it cannot support an imposed
load
Composite Wall A wall built of a combination of two or
more masonry units of different types of
materials that are bonded together, one
forming the facing of the wall and the other
the backup.
Composite Wall
Retaining Wall
A retaining wall is a structure that holds back soil or rock from a building, structure or area.
Retaining walls prevent down slope movement or erosion and provide support for vertical or near-vertical grade changes.
Cofferdams and bulkheads, structures that hold back water, are sometimes also considered retaining walls.
Retaining walls are generally made of masonry, stone, brick, concrete, vinyl, steel or timber.
Retaining Wall