Modern Methods of Construction Flashcards
Features of traditional construction methods (7)
- Loadbearing walls/onsite construction, 2. Non-framed buildings, 3. Massive materials/labour intensive, 4. Low efficiency, 5. Slow, 6. Quality control issues (In-situ construction), 7. Construction waste
Features of MMC (8)
- Non-loadbearing walls/offsite construction, 2. Saving materials and labour, 3. Fast, 4. Higher efficiency, 5. Quality assurance, 6. Reduced waste, 7. sustainability
Off-site construction techniques (7)
- Volumetric modules (prefab concrete), 2. Panelised systems, 3. Hybrid systems, 4. 3D concrete printing, 5. Light Gauge Steel Framing, 6. Cross Laminated Timber (CLT), 7. Smart construction technologies
Volumetric modules (prefabricated concrete)
Entire rooms or sections of buildings are manufactured off-site as complete modules. These modules are ready-made rooms transported to the construction site for assembling. (popular for bathrooms and kitchens) (modules - ready made rooms) AKA pods
Panelised systems
Walls, floors, roofs are assembled into panels off-site, then transported to the site and connected to form the building’s structure. EG curtain walling, infill walling
difference between volumetric modules and panelised systems?
Volumetric is 3d and panels are a 2D plane with a certain thickness
Hybrid systems
The concrete in construction is the combination of precast and insitu concrete. Combines various materials and construction techniques to create customised modular solutions. A mix of volumetric modules, panelised systems, and other prefabricated components
Concrete 3D printing
Large scale 3D printers are used to print concrete structures layer by layer for constructing walls, bridges, and other structural components.
Light Gauge Steel Framing (steel framing systems)
Pre-engineered steel components are manufactured off-site and assembled on-site to create the structural frame of the building. Popular for residential and light commercial construction
Cross Laminated Timber (CLT)
CLT panels are manufactured off-site by layering and gluing together dimensioned lumber. On site these panels are assembled into the structural elements of a building
Smart Construction technologies
BIM (building information modelling), digital twin (a bit like bim but includes real time data and analytics) , industry 4.0 + AI, VR, AR
Modular construction
Factory produced building units that are assmebled as large volumetric components of a building. Used in hotels, education, student accomodtion,
Pods
Small, complete volumetric rooms. Usually non-structural and used within a loadbearing structure. The enclosure can be of steel frame, timber frame, concrete or composite constructions. Typically bathrooms
Panelised systems - open panels
Panels delivered to site where windows, services, linings are fitted. All structural components are visible
Panelised systems - closed panels
Like open panels but can have windows and doors. Internal structural components can only be seen around perimiter of panel
Panelised systems - concrete panels
Structural wall panels, which can include cladding, insulation materials, windows and doors
Panelised systems - Composite panels
Made from a combination of different materials that act together to provide structural support. Structural insulated panels are a specific form of composite panel.
Panelised systems - Structural insulated panels (SIPs)
Sandwich construction comprising two layers of sheet material bonded to a foam insulation core. They do not rely on internal studs for their structural performance. Used primarily as wall and roof panels.
Sub-assemblies and components (10)
- prefabricated foundations, 2. Floor cassettes, 3. Roof cassettes, 4. Preassembled roof structure, 5. Prefabricated dormers, 6. Prefabricated chimney stacks, 7. Wiring looms, 8. prefabricated plumbing, 9. Timber I-Beams, 10. Metal web joists
sub-assemblies and components - pre-fabricated foundations
A series of prefab ground beams and other components to form foundations quickly and accurately
sub-assemblies and components - floor cassettes
prefab panels designed for floor construction. Fewer labour hours are needed per sqm and reduced work at height has potential health and safety benefits
sub-assemblies and components - roof cassettes
Pre fab panels designed for pitched roofs. Stiff and designed to leave the loft free of struts and props, allowing easy production of ‘room in the roof’ construction. Allows the roof to become watertight more quickly than conventional constructions
sub-assemblies and components - preassembled roof structure
Roofs assmbled on the ground before constructing the shell of the building. Can then be craned into place after the superstructure is in place, creating a weather tight structure more quickly than assembling the roof in situ
sub-assemblies and components - prefabricated dormers
Factory made dormers can speed up the process of making the roof watertight. (Dormers are squares/windows petruding from pitched roofs)
sub-assemblies and components - prefabricated chimney stacks
factory made lightweight chimney stacks for mounting on the roof structure without the need for masonry work, making them suitable for lightweight construction
sub-assemblies and components - wiring looms
cabling systems manufactured so they can be assembled quickly with relatively unskilled labour. Cables are manufactured in various lengths an terminated with easy to use plugs
sub-assemblies and components - prefabricated plumbing
Pipework and fittings pre-assembled for use in volumetric units for quick work
sub-assemblies and components - Timber I Beams
Lightweight joists, studs or rafters manufactured with a timber sheet material web to make an I beam. Very stiff for their weight and can be used to create structures with larger unsupported spans for increased flexibility
sub-assemblies and components - metal web joists
Lightweight joists comprising two timber flanges separated by light gauge steel lattice webs, as with timber I beams, large room spams are possible
onsite MMCs - tunnel form in-situ concrete
concrete bays case between L shaped steel shutters. The ends of the bays are infilled with other materials to create a habitable space. More efficient when used for large numbers of repeat units
onsite MMCs - Insulating concrete formwork
Insulation in the form of hollow blocks or sheets used as permanent shuttering for concrete to create the external walls of a dwelling. Airtight and thermally efficient dwellings are created using this.
onsite MMCs - aircrete
aerated concrete products, used to form the major elements of a structure. Uses conventional skills and is suited to both low and high output volumes
MMC - disadvantages (8)
- Inflexibility for late design change, 2. Higher initial costs, 3. Potential higher overall costs, 4. Less durability, 5. Delays in obtaining planning permission, 6. Regulatory complexities, 7. Training requirements of site and professional staff, 8. Skills shortage in logistics and planning
Operational carbon
The co2 and other greenhouse gases emitted from a building’s energy use, EG heating, hot water, coolng, blah blah
Embodied carbon
The carbon emissions incurred from the manufacture, transport and erection of building materials used in construction as well as disposal
Embodied energy of building materials, high to low (4)
- Aluminium (super high), 2. Steel (high) 3. Concrete (low), 4. Timber (very low)
Sustainable building solutions - passive (6)
- High thermal mass/good insulation, 2. Double/triple glazing windows, 3. Window curtains/blinds, 4. Air tightness, 5. Summer shading devices, 6. Natural ventilation
Sustainable building solutions - active (8)
- Energy efficient lighting, 2. Solar thermal systems, 3. Air-source heat pumps, 4. Geothermal heating systems, 5. Wind energy systems, 6. Hydrogen heating systems, 7. Biomass heating systems, 8. Building energy management systems
