Arch205 Materials and building construction I

buildings Buildings are made to house, support and inspire a range of human activities in response to various needs like societal, cultural, economic, political etc. Buildings are made in natural and built environments that has constraints as well as opportunities for development. Contextual forces need to be carefully considered in planning, designing and constructing buildings.

Natural Environment

Built Environment Created by man with or without the aid of the natural environment.

ENVIRONMENTAL FORCES Microclimate Topography Natural habitat Sun path Wind direction Water flow etc Stepped elevation or similar treatment to blend with the natural environment Split level construction to form economic shape Shape determined by existing trees

REGULATORY FORCES Zoning regulations like Muscat Bye Laws, Time Savers Standards, BIS, Building Codes etc. are the regulatory factors. Land use patterns, site activities, limitations to the size and shape of the building mass and location of building on site etc. are regulated by these forces.

Other forces Construction, use and maintenance of a building also influence the transportation systems, utilities and other services. Always think of how much development is possible on a site without exceeding the capacity of service systems, without consuming too much energy or causing environmental damage. The challenge is to create optimum solutions/designs !!

BUILDING SYSTEMS Structural System 1. Foundation/Subgrade (SITE) 2. Superstructure (STRUCTURE) Enclosure System 3. Exterior Envelope (SKIN) 4. Interior Partitions (SPACE PLAN) 5. Mechanical Systems (SERVICES) 6. Furnishings (STUFF)

Structural System Structural system of a building is designed and constructed to support and transmit all loads safely to the ground without stressing its members. Superstructure- vertical extension of a building above the foundation. Columns, beams and load bearing walls support floor and roof. Substructure is the foundation of a building.

Enclosure systems Enclosure system is the shell or envelope of a building consisting of roof, exterior walls, windows and doors. Roof and exterior walls protect interior spaces from weather, and control moisture, heat & air flow through the building parts. Exterior walls and beams also reduce noise from outside, provide security and privacy for indoor activities. Doors provide physical access. Windows provide light, air and views. Interior walls and partitions subdivide building into spaces.

Mechanical systems Mechanical systems provide services to a building. Water supply provide water for drinking and other uses. Sewage disposal system removes fluid and organic waste. Heating, Ventilation and Air Conditioning (HVAC) provide comfort. Electrical systems controls and distributes power supply. Vertical transportation systems carry people and goods to different levels. Fire-fighting systems detect and put off fire. Recycling and waste disposal systems remove and recycle other wastes.

Building systems When we select, assemble and integrate various building systems in construction of a building, the following factors are to be taken into account: Performance requirements Aesthetic qualities Regulatory constraints Economic considerations Environmental impact Construction practices

Building systems Cost over time Lifetimes Years 1.Foundation/ Subgrade structure 10% 2.Structure (superstructure) 30-40% 3.Exterior Wall 10-20% 4.Interior Partitions 10% 5.Mechanical Devices 30-40% Lifetimes Years 1.Foundation/Subgrade 50-100+ 2.Superstructure 50+ 3.Exterior Wall 25+ 4.Interior Partitions 10-30 5.Mechanical Devices 20

Basic structural forms SOLID CONSTRUCTION Load bearing walls. Structurally limited. Used in buildings of low height and short spans. Any opening in load bearing wall makes it weaker. A lintel or arch must support the load above the door or window and transfer to adjacent sections of walls.

Basic structural forms FRAMED OR SKELETAL CONSTRUCTION Made of columns and beams to form a skeleton.

Basic structural forms TRUSSED STRUCTURE The basis of a truss is the geometric rigidity of a triangle. All linear members of truss are either in axial tension or compression. No bending happen in truss elements.

Basic structural forms ARCHES Arches are curved structures for spanning an opening. Supports vertical load by axial compression. Transforms vertical forces into inclined components and transmits to abutments on either side of the archway.

Basic structural forms VAULTS Vaults are arched roofs over a hall or room. Vaults behaves as arches extended in 3-dimensions. To counteract/oppose arching action, supporting walls should be buttressed.

Basic structural forms HIGH RISE STRUCTURES Tall buildings have more effects from lateral forces. Rigid frame should be braced to make tube structure, that has perimeter lateral force resisting structure.

Basic structural forms DOMES Dome is a spherical surface structure with circular plan.

Basic structural forms SHELL STRUCTURE Shells are thin, curved plates made of RCC or steel plates. Cover large openings, but not suitable for concentrated loads.

Basic structural forms CABLE STRUCTURE Uses cable as main support element. These are high tension cables purely used for tension and not compression. Cable suspended and cable stayed structures are two types.

Basic structural forms MEMBRANE STRUCTURE Membranes are thin, flexible surfaces that carry loads through tension. Either suspended or stretched between posts, or supported by air pressure.