WEEK 5
STRUCTURAL CONCEPTS # 640263 KATHRYN RANDALL-DZERDZ
Structural Systems a) FOUNDATIONS AND FOOTINGS: transfers and distributes the load/s of the building to the ground (fig.1). b) PRIMARY STRUCTURE: the structural system that transferrs live and static loads through the the building and to the ground (fig.2).
LOAD-BEARING COLUMNS
Figure 1; Concrete footing. (Sketch: K. Randall-Dzerdz)
c) SECONDARY STRUCTURE: the non-loadbearing structure of a building consisting of walls, doors, windows and features that contribute little to the load-bearing capacity of the structure (fig.3). Figure 2; Columns of the primary structure.
Note: unless otherwise stated, all architectural images are a attributed to Cox Architects and Planners.
Figure 3; Doors and windows of the secondary structure.
Figure 4; Brickwork
Figure 5; Structural concrete
Figure 7; Solid concrete block
Figure 6; Varied use of steel
Figure 8; Grout
Figure 9; Loose insulation
Brick (fig.4): existing walls. Structural concrete (fig.5): slabs, footings, walls. Steel (fig.6): structural framing. Concrete block (fig.7): walls. Grout (fig.8): used between some joints. Loose insulation (fig.9): between walls, floors and roof-spaces.
Structural materials
Note: unless otherwise stated, all architectural images are a attributed to Cox Architects and Planners.
joints and fixings Joints observed are predominantly fixed: Welded: due to the primarily steel structure of the Eastern Resource Centre, many elements are connected through the heating and subsequent cooling and hardening of metals. This cooled, solid mass that is developed creates a fixed joint (fig.10). Bolted: Many elements are bolted together with multiple bolts to create a fixed joint (fig. 11). If singular bolts were used on these areas, a pin-joint may be formed allowing movement in the structure. Chemset: Chemset is used in some instances (fig.12) in conjunction with bolts to reinforce the bond between the bolt and the element it is being affixed to.
Figure 11: Bolted fixing.
Figure 10: Welded joint.
Figure 12: Chemset fixing.
Note: unless otherwise stated, all architectural images are a attributed to Cox Architects and Planners.
The structure must consider connections to existing buildings, not just joints between structural elements
sustainability AND ENVIRONMENT Many processes within the acquisition, manufacturing and transportation of structural materials will produce carbon dioxide and consume energy. Data collected in the United Kingdom by Tata Steel (2002) reveals that the production of one tonne of steel may produce almost one tonne of carbon dioxide. However, this may be reduced to approximately 0.4 tonne if 100% recycled steel is used. The production of steel may also consume about 17 GJ of energy. This is termed embodied energy; the energy that is used to manufacture and construct the steel component. The more complex the steel element, the more energy it consumes, and the more carbon dioxide it produces.
GLOSSARY: CONTINUOUS SPAN A continuous span extends, without joints, over multiple supporting structures. A continuous span is often utilised in bridges, and may be used where long spanning elements require support at multiple points throughout their length.
Concrete used in footings and walls cannot be recycled or broken down into its constituent parts and reused. Consideration appears to have been taken in the construction of a new structure, and existing concrete slabs utilised as best as possible to avoid removal and relaying (fig.13). This is also a more economical approach. Steel has a high strength-to-weight ratio, therefore less material may be used compared to other materials, resulting in a more economical and efficient structure. Cheaper materials may not be an economically wise choice in the long-run, and may break down quicker or require more energy and revenue to maintain.
Figure 13: Utilisation of existing concrete.
References: Ohio Department of Transportation n.d., ‘Bridge Terms - C’, Available: http:// www.dot.state.oh.us/Divisions/Engineering/Structures/bridge%20operations%20 and%20maintenance/PreventiveMaintenanceManual/BPMM/glossary/c_terms.htm [2013, September 5]. Tata Steel 2002, The carbon footprint of steel, Available: http://www.tatasteelconstruction.com/en/sustainability/carbon_and_steel/ [2013, September 5].