WEEK 1: Construction materials: They are building materials used in the construction industry to create buildings and structures. Some considerations required for construction materials are:
Strength: Whether the material is strong or weak and how durable will it be. Stiffness: For aesthetic as well as for convenience to built the structure, materials should be stiff or flexible according to the needs of the specific structure. Shape: Constructing materials will be needed for building shapes of different kinds be it linear, planar or volumetric. Material behavior: Isotropic and anisotropic materials are used for different purposes of the building. Economy and sustainability: The material should be economically viable and als o be sustainable to a certain degree.
Site analysis for cnstructiong a building:
Path of the sun
Map climatic conditions
Determine point of access
Direction of prevailing winds
expected amount of rainfall
Analyze the ground slopes
Chart existing water features
Identify slopes unsuitable for developmen t
Draw the area of the site
Indicate existing set backs
Loads distribution on a building:
Loads on a building
Live loads(Acts vertically downwards )
Dead loads(Load s act downwards )
Impact loads(Movi ng vehicles,eq uipments and machinery)
elements permenatly attached to the building.
Wind loads (Horizontal prressure on windward vertical surfaces and normal to wind ward roof surfaces.)
Earthquake loads (Both horizontal and vertical forces apply)
Tension and compression : Tension is the pulling force exerted on an object which stretches and elongates the object. While compression is the opposite of tension which causes the and inward force on the object. ď‚ˇ Picture on the left shows a structure built completely on compression forces. ď‚ˇ Diagram below illustrates the compression and tension on a beam.
Load paths: It is the direction of the transfer of loads in a structure through connected members. It processes from a higher point to the footings of the structure.
WEEK 2: Structural systems:
Solid- These were used in early structures. It was mainly based on compression. Materials used were mud and bricks.
Surface- Planar structure eg:The Sydney Opera House. Skeletal structure- Most commonly used in modern times because of its efficiency. Very effective in transferring load to the ground.
Membrane- Covers large area efficiently and with very economically. These structures are strong in tension. Hybrid- They are fairly new. These contain a combination of other structural systems. These are also effective in covering large area economically. ETFE materials are used.
Considerations for constructing a building:
Factors to be consid ered Aesthe tic Qualiti es
Perfor mance require ments
Structu ral compat ibility
Fire resista nce
structu ral safety.
Control over heat,air flow, temper ature.
Resista nce to weathe ring.
Preffer ed qualitie s of form,m assing, color and pattern .
Relatio nship of buildin g to the site.
Econo mic consid eration s:
Life cycle cost
Enviro nmenta l Impact:
Energy saving s
Energy efficien cy
Use of resour ces
ESD (Environmentally Sustainable Design): Some factors to look at:
Orientation of the building with regards to the sun path, wind paths to allow use of active and passive shading and regulation of thermal mass energy. Ventilation for air circulation: Example: Night –purge ventilation- Cooling off the heat collected by the building during the night by opening the windows in the building automatically through a programmed system. Consumption of less energy by using renewable energy like solar energy. Embodied energy- taking into considerations of the materials to be used, which should be have less embodied energy.
Building systems: â€œA system can be defined as an assembly of interrelated or interdependent parts forming a more complex and unified whole and serving a common purpose.â€? (Ching and Adams, 2001).
Building Systems Structura l systems (support and transmit applied gravity and lateral loads safely to the ground.) Superstr ucture (Vertical extensio n of a building above the foundati on)
Substruc ture (underlyi ng structure forming the foundati on of the building)
Enclosur e system (Shell or envelope of the building )
Columns , beams and load bearing walls support floor and roof structure s.)
Roof and exterior walls to shelter interior spaces from various weather conditio ns.
Doors for access.
Mechani cal systems (Provide essential services to the building) Windows provide access to light ,air and view.
Water supply sytem.
Sewage disposal system.