Week 6 Constructing Journal

Construction Journal Submission Report Week Five and Six: Structural Concepts Nicole Tan 641433 CASE STUDY BUILDING: EASTERN RESOURCE CENTRE STUDENT SERVICES CENTRE Note: We did not have enough time in the Week 5 tutorial to conduct this activity and so this week’s journal is slightly modified.

DESCRIPTIONS AND CLASSIFICATION OF STRUCTURAL SYSTEMS Foundations and footings:  



The student centre is located on level three of the ERC and so does not have directly attached footings or foundation system.

The two types of foundation systems can be found on level 1. o Strip footings which are the continuous spread footings of foundation walls (Ching 2008) o Concrete pad footings. According to Ching (2008), the presence of a concrete slab also indicates that the soil is stable, uniformly dense and contains no organic matter.  The presence of a base plate allows the concentrated load imposed by a column to be distributed so the pressure does not exceed the bearing capacity of the concrete slab (Ching 2008) The floor level is situated atop a reinforced concrete slab which sits above the ceiling of level two. As can be seen in Figure 1, there are a series of beams running across the ceiling which supports the floor of level 3 (student centre). o There are air-conditioning ducts sitting below the concrete slab of level 3 and thus the floor of the student centre contains air-conditioning ducts too.

Figure 1. Sketch of foundation system section

Figure 2. Sketch of floor penetration/ceiling section

Primary structure: Many of the structures of this building are tailored specifically to the design and measurements of the building. 



Horizontal members: o Beams (tapered), Universal beams o Reinforced concrete slab o Rectangular hollow section o Parallel flange channel Vertical members: o Walls (of the café and the bluestone wall) o Universal columns, columns (only present at the doorways of the building. The foyer of the student centre is column-less).

Figure 3. Sketch depicting a section of the student centre displaying the roof beam system and the bluestone wall. The glass panels sit above the roof beam.

Figure 4. Sketch of roof beam detail and the pin joint connecting the beam with the bluestone block.

Secondary structure:  

  

Purlins (on the roof) Mullions (separates elements of a door or window) o Louvre mullions o Mullions Lintles (above doors) Fabricated T section glass support beam Window header

Figure 5. Sketch of the secondary structure present around the air lock door section.

IDENTIFICATION, DESCRIPTION AND LOCATION OF STRUCTURAL MEMBERS 



The student centre only uses two key structural materials: o Steel  The steel is used for the beams and tapered beams  Steel is much lighter and hence is appropriate for the ceiling members since the student centre foyer doesn’t contain any columns and rely on the walls to carry its force.  Steel also has high tensile strength and is resistant to fracture which enables it to be a good material for the cantilevering beams which stretch across a wide span without supporting columns. o Concrete  A reinforced concrete slab is used for the floor. It would also contain shrinkage and temperature reinforcement.  The concrete slab is a one way slab. It utilises T-beams which are suited to longer spans and heavier loads (Ching 2008).  It is clear from the structural drawings that the beams are evenly spaced which allows loads to be distributed more uniformly.

Bluestone wall o The existing bluestone wall can be considered a structural member as there are beams that simply rest on it and hence the wall carries their weight

STRUCTURAL JOINTS 

Welds and bolts are used to join steel elements like the beams o Fixed joints are used for the beams which the battens are attached to (at the entrance of the building) o Pin joints are used where the beams rest on the bluestone wall to ensure zero moment.  Pin joints also allow for expansion and shrinkage of materials

SUSTAINABILITY AND ENVIRONMENTAL ANALYSIS 



Because the majority of structural elements are made from concrete and steel, the carbon footprint and embodied energy of the student centre is fairly high o Many steel elements are fabricated off site as they are ad hoc and tailored specifically to the building and hence add towards transportation and extra processing methods carbon and energy costs o For example, steel on average contains 20.10MJ/kg compared to timber which is only 4.5MJ/kg (Department of Climate Change 2013).

The concrete slabs are in-situ which somewhat reduces its transportation costs compared to pre-fabricated concrete.

Note: Instead of building the structural model in Week 6’s studio, we (as a class) went through each of the drawings for all four buildings.

QUEENS COLLEGE EXTENSION: 



FOOTINGS AND FOUNDATIONS o Presence of strip footings and reinforced concrete footings o Pad footings are located at columns. o Bored piers  This indicates that the soil is not stable and of poor bearing capabilities thus foundations need to be laid deeper into the soil structure where it is stable (Build Right 2012). o The ground slab has been constructed in sections and it connects the footing system.

PRIMARY STRUCTURES: o Reinforced concrete and metal columns o Concrete beams

ORMOND THEOLOGY CENTRE RECEPTION:  



FOOTINGS AND FOUNDATIONS o Reinforced in-situ concrete foundation PRIMARY STRUCTURES: o Concrete and steel columns o Roof o Concrete slabs SECONDARY STRUCTURES: o Purlins made from cold, bent steel so it is small and light-weight o Soffits o Stud walls o Noggins

MSLE BUILDING:  

FOOTINGS AND FOUNDATIONS o Reinforced concrete slab PRIMARY STRUCTURES: o Existing load bearing wall o Universal beams o Parallel flange channels  A plate is used to connect this to the wall.

It is clear that the drawing conventions, abbreviations and symbols are consistent across all buildings. Furthermore, most of these buildings also contain similar elements, materials and systems albeit in different configurations. This links to the concept of ‘following traditions’ in construction as many builders and designers choose to incorporate tried and tested methods of construction.

STRUCTURAL MODEL FOR THE ERC STUDENT SERVICES CENTRE ROOF BEAM

EXISTING FOUNDATION WALL OF THE DOUG MCDONNEL BUILDING

EXISTING BLUESTONE WALL OF THE ERC LIBRARY

SLOPING BEAM

MULLIONS WHICH SUPPORT GLASS PANELS

COLUMNS CONCRETE SLAB

Figure 6. Structural system present at the entry of the student centre (Tan 2013).

ROOF BEAM WINDOW HEADER BEAM

MULLIONS WHICH SUPPORT GLASS PANELS THIS COLUMN SUPPORTS THE ROOF BEAM AS WELL AS THE WALLS FOR THE STUDENT CENTRE AREA

COLUMNS

Figure 7. Structural system present at the Western end of the student centre foyer (Tan 2013)

ROOF BEAMS

GLASS SUPPORT BEAMS

GLASS HEADER

LINTEL

Figure 7. Structural system present at the Western end of the student centre foyer (Tan 2013).

THE ROOF BEAMS HAVE TO BE MADE FROM LIGHTWEIGHT STEEL AS IT CENTILEVERS ACROSS A FAIRLY LARGE SPAN

THE CEILING OF THE STUDENT SERVICES DESK IS SUSPENDED FROM THIS BEAM

THESE COLUMNS SUPPORT THE STUDENT SERVICES AREA

Figure 8. Structural system present from the interior of the student centre (Tan 2013).

LOAD PATHS At the foundation:

BASEPLATE TO DISTRIBUTE AN OTHERWISE VERY CONCENTRATED LOAD FROM THE COLUMN

THE LOAD FROM THE CONCRETE SLAB IS MORE EVENLY DISTRIBUTED

Irwin Consult Pty. Ltd. 2013 From the roof:

THE ROOF BEAMS ASSIST IN TRANSFERRING LOADS FROM THE GLASS PANELS TO THE COLUMNS AND CONSEQUENTLY TO THE FOUNDATION OF THE BUILDING THE EXISTING WALL ASSISTS IN LOAD TRANSFER FROM THE ROOF BEAMS TO THE FOUNDATION

THE GLASS WINDOWS ADD TOWARDS THE LOAD WHICH THE BEAM CARRIES

At a doorway:

The load imposed by the wall is transferred to the lintel which transfers it to the adjacent walls around the opening

LINTEL