NOMBRE DEL CARGO RESPONSABILIDAD
2. Gerencia del Trabajo de Grado
3.1. Cambio de fecha de entrega de informe final de Trabajo de Grado
Description and U-Value (W/m2K)
Section Layers
Low-rise module ceiling
U-Value = 0.81
1. 15mm plasterboard 2. 12.5mm plasterboard
3. 75mm steel studs with 60mm Rockwool insulation
4. 15mm OSB Low-rise module ceiling with
roof insulation, ventilated void and pitched tiled roof
U-Value = 0.16
1. 15mm plasterboard 2. 12.5mm plasterboard
3. 75mm steel studs with 60mm Rockwool insulation
4. 15mm OSB 5. 150mm insulation 6. Loft space
7. 40mm roof tiling including batten space (30° pitch)
Medium-rise module ceiling
U-Value = 0.80
1. 15mm plasterboard
2. 15mm plasterboard with a foil backed vapour control layer
3. 75mm steel studs with 60mm insulation between joists
4. 15mm OSB Medium-rise module ceiling
with roof insulation, ventilated void and pitched tiled roof
U-Value = 0.16
1. 15mm plasterboard
2. 15mm plasterboard with a foil backed vapour control layer
3. 75mm steel studs with 60mm insulation between joists
4. 15mm OSB 5. 150mm insulation 6. Loft space
7. 40mm roof tiling including batten space (30° pitch)
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4.3.8 Modular Windows
The windows used within modules varied based on project requirements, in terms of size, appearance and thermal properties. There were restrictions on the size and location of windows within modular walls, for structural reasons. Some projects included large windows that required alterations to the modular design, but typically windows were kept within the standard limitations to avoid the extra time and cost involved in redesigning the modules. Typically aluminium framed double glazed window units were used, of a standard thermal performance, (with a U-Value of 2.0–2.2 W/m2K), but many projects also had different windows. Module windows were installed in the factory, but no generic design or manufacturing documents were found, however there were detailed drawings for some projects which show a number of installation options. The windows had steel angles fitted to them (Figure 4.12), and these were then bolted to the steel frame, (Figure 4.12), they could be fitted in-line with the module wall (Figure 4.12), protruding past the module wall (Figure 4.12), or anywhere in-between. The quality of this detail is discussed in Chapter 7.
Figure 4.12 (far left): Modular windows with steel angles and DPC fitted prior to delivery to factory Figure 4.13 (centre left): Window fitted to module in factory so it protrudes past wall
Figure 4.14 (centre right): Section drawing of modular window fitted in-line with module wall [ 2012] Figure 4.15 (far right): Section drawing of modular window fitted to protrude past module wall [ 2012]
4.4 Corridor Panel and Cassette Design
Wall panels, floor cassettes and ceiling cassettes were used to create the corridors between modules. Floor cassettes were used on all storeys to create the corridor floors (Figure 4.16). Ceiling cassettes were used on the top floor only. Corridor panels were used to divide the corridors between flats and for external walls where the corridor met the external facade (Figure 4.17). Corridors could also be provided in modular form, but it appears that panelised corridors were used for all projects.
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The corridor components utilised the same steel C-sections as the module panels. However, unlike the modules, they were not finished in the factory, and required work on site; typically the addition of plasterboard, insulation, flooring, paint, mechanical and electrical services, and false ceilings.
Figure 4.16 (left): Corridor onstruction on site – floor casettes fitted between modules [ 2012] Figure 4.17 (right): Corridor construction on site – corridor wall panels and floor cassettes [ 2012]
4.5 Shower Pods
Shower pods were used in all bedroom and studio flat modules (Figure 4.18). initially manufactured their own shower pods, but later switched to purchasing them from other manufacturers. They were purchased fully fitted including plumbing and electrical wiring, and simply had to be installed within the module. The size and internal finish of the shower pods varied by project, for example the pods used for hotel projects were larger with a higher specification of fittings compared to student halls.
Figure 4.18: Shower pod [ 2012]
4.6 Component Sub-assemblies
The use of component sub-assemblies is standard in all construction projects, and therefore all buildings use this form of offsite construction. However, the type of sub- assemblies used in offsite construction can differ from those used on a traditional construction site, such as modular wiring systems, (Figure 4.19).
Figure 4.19: Modular wiring system
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4.7
Modular Fabrication
The modules and cassettes were manufactured in a factory in . The factory operated a production line, with the factory floor divided into areas, each dedicated to different tasks (Figure 4.20 and Table 4.6). Machinery was used to automate much of the construction process. When the factory was operating at maximum, one module could be completed every 55 minutes. Employees typically worked in one area, repeating the same task or set of tasks throughout the day. Employees were typically unskilled or semi-skilled; they were fully trained in the factory to perform the tasks required. Over time, some employees were trained to work in more than one production area.
Module fabrication in the factory is detailed in Appendix H. Once module fabrication was complete, the modules were transported to site by lorry for installation. The modular construction process on site is detailed in Appendix I.
Figure 4.20: factory floor schematic layout – based on floor plan [ 2012] Atrium 2 Atrium 1 Atrium 3
Cassette Rolling and Framing
Floor Butterfly CNC Lazzari Saw Area Grave Yard Butterfly Nailbridges B a t h r o o m L i n e Bedroom Line Kitchen Line Finish / Cover / Lift
Paint Line
Ship / Box
Show Flats
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Table 4.6: Overview of tasks undertaken in each factory production area
Production Line Area Tasks Performed in Area Automated
Rolling Steel cut and rolled into C-sections Yes
Framing Steel C-sections connected together to create structural
frames, for wall, ceiling and floor panels.
Yes
CNC Lazzari Saw Boards cut to size using a CNC driven saw Partly
Nailbridges Boards and some insulation nailed to the steel frames to
create panels
Yes
Butterfly and Floor Butterfly
Joints between boards on the panels sealed Heating pipework fitted within floor panels Electric wiring fitted within ceiling panels
Fire insulation fitted between studs in ceiling panels Panels moved to the next part of the production line using a machine called a butterfly
No
Paint Line Wall and ceiling panels painted and dried
Ship/Box Floor panel completed, then shower pod fitted to it,
followed by four wall panels and finally one ceiling panel to create a module
No
Bathroom Line Bathroom pods stored here and lifted onto the floor panel
on the Ship/Box line
No
Kitchen and Bedroom lines
Modules fitted out internally, with electrics, radiators, plumbing, flooring, furniture and appliances.
Electrics and plumbing tested
No
Finish/Cover/Lift Windows fitted
Fire insulation fitted between wall studs Racking boards fitted if required
Waterproof membrane fitted
No
Cassette Steel C-sections used to create the floor, wall and ceiling
panels for corridors
Partly
Show flats Show modules completed to different specifications N/A
Graveyard Material storage area
Area for miscellaneous tasks, such as fitting out structural steel modules for modular stairwells
N/A
Atria Access for lorries to deliver equipment and load
completed modules for transport to site
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4.8
Operation and Management
As a company, operated as a sub-contractor, and they had little involvement in the design or construction of buildings unless it directly related to the modular construction. Each project would follow the traditional construction process. The building would be designed by the architect to meet the project brief; this design would then be “modularised” by (Figures 4.21 and 4.22). Modularisation involved dividing the internal space into modular units, quantifying the number and size of modules and corridor components required, and their interfacing within the building. Modularisation was an iterative process, involving collaboration between and various parties such as the architect, structural engineers, structural contractors, consultants, window suppliers etc. This process ensured the modularised design met all requirements, primarily safety and regulatory requirements, but also interfacing requirements between components.
Figure 4.21 (left): Drawing of architect's building design [Architect 1, 2009] Figure 4.22 (right): Drawing of modularisation of architect's design [ 2012]
4.9 Standard
Product
In total, constructed around 40 halls of residences using modular construction. These halls are all unique, and no two projects were identical, although many were of a similar style and appearance (Figures 4.23 to 4.26). Different architects were used for different projects, although some architects worked on a number of projects for It appears that the decision to use modular construction was not necessarily pre-determined from the inception of a project, and had to compete for tendering with other contractors.