Design and Specification Flashcards
(16 cards)
What is Modern Methods of Construction
‘Modern Methods of Construction’ (MMC) is a wide term, embracing a range of offsite manufacturing and onsite techniques that provide alternatives to traditional house building.
What are some examples of Modern Methods of Construction
- Modular construction whereby three-dimensional units are produced in a factory
- Non-structural pods (typically fully-fitted kitchens or bathrooms) which are incorporated within load-bearing structures;
- Panelised systems which are transported to site as flat panel units.
- Sub-assemblies and components such as roof frames and floor cassette
What are some key peices of documentation relating to Modern Methods of Construction
2005 - The National Audit Office published ‘Using modern methods of construction to build homes more quickly and efficiently’
2017 - The National House Building Council (NHBC) launched an online MMC hub.
2018 - a forward-thinking solution to the UK housing crisis
What is the RICS report a forward-thinking solution to the UK housing crisis
The RICS has released a paper calling on government and the construction industry to embrace Modern Methods of Construction (MMC)
What are some Criticisms of Modern Methods of Construction
- Difficulty of defining the precise meaning of ‘modern methods of construction’
- A shift in risk - All risk will lie with one or two cotractors rather than a series of smaller contractors especially with modular units.
- The House of Lords Science & Technology Committee enquiry “undermine investment in British Manufactured masonry products that are preferred by consumers”
- Chemistry building at the University of Nottingham fire a fire occoured when the building was 70% complete. Gaps between the modular units were identified as being a factor as to why the fire was not contained
What is cross laminated timber
CLT is planed and kiln-dried to reduce moisture content, then stacked into layers at 90 degrees to the layer below, gluing the lamellas together. CLT has been in use since the mid-1990s. There are some variations of this including dowel laminated timber, panels and beams.
What are some advantages of CLT compared to steel or concrete
Lightweight - CLT is approximately 720kg/m3 whereas concrete is approximately 2400 kg,
Reduced carbon - Embodied Carbon +976 tonnes CLT , +2,000 tonnes Concrete of a CLT flat,
Larger spans - Used for sportcenters such as Richmond Olympic Oval and bridges such as Accoya Glulam Bridge at Sneek
What is a universal beam
A Universal Beam is primarily used a horizontal load bearer. The section is often taller than a Universal column.
What is a universal column
A column is designed to support a compressive load. The web section is similar or equal in width and height to the flange sections. The web is a bit thicker in a column. Meaning it can be used as a beam.
What is a Rolled steel Joist
Traditionally specified before BS 4-1:2005 Hot rolled rather than extruded. This can be identified by slightly slopped flanges due to manufacturing process.
What is Modular construction
‘Modular construction’ is a term used to describe the use of factory-produced pre-engineered building units that are delivered to site and assembled as large volumetric components or as substantial elements of a building
What are the benifits to Modular construction
Safer Construction - Eliminates most onsite hazards due to being mostly off site. The only significant hazard remaining is working at height.
Reduced Construction Schedule
Reduced Waste - When building in a factory, waste is eliminated by recycling materials, controlling inventory and protecting building materials
Improved Air Quality - completed in a factory-controlled setting using dry materials, the potential for high levels of moisture being trapped in the new construction is eliminated.
Imporved Qulaity Assurance - Achieved through repetition, inspection and operating in a factory-controlled environment
What are the disadvantages to Modular construction
Smaller Rooms - Due to the limatitions of transportations the room sizer are limited
Transportation Challenges - Difficulty transporting and handling modules due to their large weight and size can be costly and challenging within the confines of a small constructioin site.
No design changes - Due to the nature of modular construction alterations are near impossible and expensive.
What are the types of load on a building
Dead loads refer to the structure’s self weight and generally remain constant during the structure’s life.
Live loads, Live loads, also known as imposed loads, are usually temporary, changeable and dynamic. These include loads such as vehicle traffic, occupants, furniture and other equipment.
Enviromental loads
What are enviromental loads
Wind loads may not be a significant concern for small, massive, low-level buildings, but it gains importance with height, the use of lighter materials and the use of shapes that my affect the flow of air, typically roof forms.
Snow Loads are calculated by the projections made by snow at different parts of the structure, The amount of snow load depends on the height of building, size & shape of the roof, the location of building e.t.c
Earthquake Significant horizontal loads can be imposed on a structure during an earthquake. Buildings in areas of seismic activity need to be carefully analysed and designed to ensure they do not fail if an earthquake should occur.
Thermal loads All materials expand or contract with temperature change and this can exert significant loads on a structure. Expansion joints can be provided at points on long sections of structures such as walls and floors.
Ground movement such as heave and settelment can be design out by IS 1904 (1986): Code of practice for design and construction of foundations in soils.
How are loads catagorised
Concentrated loads (or point loads): Single loads that act over a relatively small area, such as column loads.
Line loads: Loads exert a load along a line, such as a partition’s weight on the floor.
Distributed (or surface) loads: These exert a load over a surface area, such as the weight of floors and roofing materials.
