Construction Technology and Environmental Services (L3) Flashcards
Which RIBA Stage is on-site construction?
RIBA Stage 5 - Manufacturing and Construction
What is buildability?
The extent to which the design of a building facilitates the ease of construction
What are the benefits of off-site construction over in-situ construction?
Safety - controlled factory environment
Quality - controlled factory environment
Programme - speed of installation can provide key programme benefits
Sustainability - reduction in waste produced
What is the difference between building works and civil engineering works?
Building works: all types of buildings such as houses, offices, shops, hotels, hospitals etc.
Civil engineering works: drainage schemes, highways, bridges, retaining walls etc.
What are temporary works?
The parts of a construction project that are needed to enable the permanent works to be built, usually required to provide safe access. Examples include scaffolding, formwork/falsework, propping.
What are hoists?
Designed for the vertical transportation of materials and or people
What is shoring?
A form of temporary support given to existing buildings and excavations, to prevent collapse or movement
What is a culvert?
A tunnel like structure constructed to allow water to flow under a road or similar obstruction
What is the purpose of a drainage headwall?
A small retaining wall structure to protect the end of the drain and prevent erosion of the embankment
What is the substructure of a building?
The lower portion of the building (in the ground) which supports the superstructure
Transmits the load of the building to the ground
Includes foundations, basements and retaining walls
What is ground heave?
Upward movement of the ground caused by soil swelling when wet (associated with tree removal)
What techniques are available for ground improvement?
Vibro compaction
Vibro stone columns
Vertical drains and vacuum consolidation
Soil mixing
Dynamic compaction
Dynamic replacement
What are the different forms of excavation?
Site clearance operations (removing vegetation and rubble)
Stripping topsoil
Reduced level dig (to reach formation level)
Cut and fill
Excavation for foundations
What are the key factors the contractor should consider when excavating?
Nature of the soil and the moisture content of the ground
Method of excavation
If ground support systems are required
Proximity of existing buildings
Depth of excavation
Underground services and drainage
Can you explain some of the techniques for waterproofing a basement?
Tanking - Materials such as asphalt, polythene sheeting, bitumen, etc. are applied internally or externally to provide a continuous membrane to the base slab and walls
Drained Cavity - This method accepts that a small amount of water seepage will occur. Cavity walls are formed, and the water seepage is collected in the cavity and drained or pumped away
Have you come across the term SUDS?
Sustainable Urban Drainage Systems
Designed to manage rain water locally, reducing reliance on drainage infrastructure
Can you detail a typical road build-up please?
Compacted and rolled type-1 subbase (100-250mm)
Base course (70-150mm)
Binder course (50-100mm)
Wearing/surface course (20-40mm)
What is the purpose of a foundation?
To provide support for structures, transferring their load to the ground to avoid excessive settlement
Typical considerations when selecting the type and size of foundations?
Total load of the building
Nature and load bearing capacity of the ground
Type of structure
Cost
Construction constraints
What are the different types of foundation?
Strip foundations
Pad foundations
Raft foundations
Piled foundations
What is a raft foundation?
A continuous slab that extends over the entire footprint to spread the load
What are pad foundations?
Typically used to support individual or multiple columns, spreading load to the ground below
What are strip foundations?
The formation of a strip of linear structure to spread the load across the area, usually supports masonry
What are pile foundations?
A pile is a column that extends deep into the ground
Where the bearing capacity of soil is poor or imposed loads are heavy, piled foundations are often required
There are two main types: End bearing and friction piles
There are two main methods: Bored and driven piles
In what scenarios might a piled foundation be the best solution for the project
Where the structure is heavy and underlying soil is weak
In areas where settlement issues are common
Where the sub-soil water table is high
Where load distribution of the structure is not uniform
Presence of horizontal forces
Can you explain how end bearing and friction piles transfer the load of the building?
End-bearing piles: Load is transferred through the pile to the strong layer
Friction piles: The pile transfers forces to the soil
What are the differences between bored and driven piles?
A driven pile is formed off site under factory controlled conditions
A bored pile is cast in-situ on site
What are the advantages and disadvantages of driven piles?
Advantages:
Piles can be precast to required specifications
Piles of any size, length and shape can be made in advance
Fast, neat and clean installation
Disadvantages:
Requires heavy equipment for handling and delivery
Increased noise and vibrations generated from driving the piles
It can be costly if piles are too short
What are the advantages and disadvantages of bored piles?
Advantages:
Any shape or size of pile can be formed on site
There is no risk of damage during delivery and installation
Reduced vibrations and noise
Disadvantages:
Significant spoils are generated that need to be handled
Reliance and coordination on multiple trades
Unlike driven piles, they do not improve the bearing capacity of the soil
What are secant pile walls?
A wall formed by installing interlocking piles which create a solid barrier free of gaps
Typically used to form a retaining wall
What is underpinning and why might it be required?
A method for repairing and strengthening existing foundations
What is the superstructure of a building?
The structural components of a building constructed above ground level (above the DPC)
The basic components include columns, beams, slabs, walls etc
What is the envelope of a building?
The boundary between the interior and exterior of a building
The materials and components include brickwork, cladding and curtain walls
What are the key considerations when designing external walls?
Weather protection
Fire resistance
Acoustic and thermal performance
Structural performance
Appearance / aesthetics
Expected lifespan
Future maintenance
Can you briefly explain what a retained facade is?
The facade of a building is preserved whilst the rest of the structure is re-modelled
Often used during the restoration of listed buildings
What are the standard brick dimensions in the UK?
Standard bricks are 215mm x 102.5mm x 65mm
How many UK standard bricks are required per m2?
60 bricks per m2
How many UK standard size blocks are required per m2?
10 blocks per m2
What are weep holes?
Small openings in the outer skin of masonry construction
Weep holes provide ventilation for the cavity and allow moisture to drain away
Can you name two different types of brick bond?
English bond - alternating courses of headers and stretchers
Stretcher bond - The most common brickwork method, with vertical joints staggered by half a brick
What is a curtain wall system?
Curtain wall systems comprise a lightweight aluminium frames onto which glazed panels are fixed.
What are movement joints and why are they used?
A movement joint is designed to safely absorb the expansion and contraction of construction materials
What are the key differences between wet rot and dry rot?
Two different types of fungi
Wet rot needs a higher moisture content to grow
Wet rot is wet and spongy, whereas dry rot is dry and brittle
What are the main components of concrete?
Cement, aggregate and water
What are the difference between dead and live loads on a structure?
Dead loads are the static forces which are relatively constant over time (Kitchens, Walls etc)
Live loads are dynamic forces from occupancy (People, furniture etc)
What are retaining walls?
Retaining walls hold back the soil behind it
Often seen where there is a change in ground elevation
What is pre-tensioned concrete?
The reinforcement is stretched across the formwork before the concrete is poured and not released until the concrete has hardened. The reinforcement shortens and induces strength into the concrete.
What is post-tensioned concrete?
Concrete is cast around tubes which will contain reinforcement, once concrete has hardened the reinforcement is threaded through and tensioned.
Can you explain what a glulam beam is?
Glue laminated timber
Glulam is made with multiple layers of solid wood bonded together with high strength adhesive to form a single structural unit
Can you explain what reinforced concrete is?
A combination of concrete with reinforcements, used to make use of the compressive strength of concrete and the tensile strength of steel at the same time.
What are the key advantages of timber frames?
Construction on site can be faster (compared to in situ concrete frames)
The structure is relatively lightweight
Timber can be aesthetically pleasing
Sustainability benefits (assuming responsible harvesting)
What are the key disadvantages of timber frames?
Skilled workmanship is required to achieve a high-quality finish
Potential for wet rot, dry rot and woodworm
Fire protection may be required
What are the key advantages of steel frames?
Faster to erect than concrete frames
Recyclable
High strength to weight ratio
Beams can span over long distances (ideal for warehouses)
What are the key disadvantages of steel frames?
Lower load bearing capacity than concrete frames
Fire protection may be required
The price of steel can be volatile
Steel frames do not have the same acoustic and thermal properties as concrete frames
What is a portal frame and when are they suitable?
Commonly used to construct warehouses
What are the key advantages of concrete frames?
Fire protection is inherent in the structure
Cladding and other finishes can be fixed directly to the frame
Provides good sound and heat insulation
High compressive strength
What are the key disadvantages of concrete frames?
Requires formwork/falsework
Slower to construct on site
Requires a bulky structure
Concrete does not span as well as steel
Long curing time - maximum strength typically achieved after 28 days
With reference to concrete frames, what is formwork?
The temporary structure used to contain poured concrete and mould it to required dimensions.
Formwork is stripped away once the concrete has hardened and can support itself
What key factors should be considered when selecting the type of structural frame?
Programme requirements
Fire protection
Acoustic and thermal properties
Market conditions and supply costs
Site logistics and general site constraints
Sustainability objectives
Future expansion requirements
What is slip form construction?
Involves pouring concrete into the top of continuously moving formwork
What is jump form construction?
The structure is cast in a series of vertical sections called lifts, with formwork jumping up to the next level
What key factors should be considered when designing internal partitions?
Fire rating and acoustic requirements
Thermal properties
Requirement for doors and internal windows
Strength and structural requirements
Robustness
Height of the partition
What is a CAT A fitout?
The provision of a basic level of finish
What is a CAT B fitout?
The provision of a space ready to move into and operate in
Can you name some common types of plasterboard?
Standard boards (white/light grey)
Fire boards (pink)
Acoustic board (red)
Moisture resistant board (green)
What is raised access flooring?
A floor sitting on pedestals above the structural slab (allowing for services)
Can you explain the difference between single phase and 3-phase electrical supplies?
Single phase has just one live wire, whereas three phase power uses three live wires
Why do we install generators in addition to regular grid power?
Generators (powered by diesel engines) act as a backup should the primary power supply fail
What is a UPS?
Uninterruptible Power Supply - used for life critical equipment in hospitals
What does HVAC stand for?
Heating, Ventilation and Air Conditioning
What do FCU, AHU and VAV stand for?
Fan Coil Unit, Air Handling Unit and Variable Air Volume system
What is natural ventilation?
A method of supplying fresh air to a building a room by means of passive forces
What is mechanical ventilation?
The intentional, fan-driven flow of outdoor air into a building
What is the purpose of a parapet?
The extension of the external building shell above roof level allows for maintenance to take place and masks the unsightly roof plant from ground level
What site surveys may be required on a typical construction project?
Topographic survey
Site investigation
Asbestos survey
Drainage CCTV survey
Utility searches
Measured surveys
Ecology surveys
Archaeological surveys
UXO surveys
Objectives of a site investigation?
To establish parameters for foundation and substructure design - engineer will assess properties and condition of soil and rock, and potential ground contamination
Which vegetation causes issues?
Japanese knotweed
Fire safety provision in a new building?
Maximum occupancy numbers
Fire evacuation plan, designated escape routes
Fire extinguishers
Fire alarms
Sprinklers
Fire dampers in ventilation ductwork
Fire barriers in floor, walls and ceilings
Fire rated roller shutters
Smoke control systems
What is a fire compartment in a building?
Compartmentation is a form of passive fire protection - the idea is to provide a compartment which limits the spread of fire and smoke, allowing for a ‘stay put’ strategy whilst the fire is extinguished
Different types of fire extinguishers
Water - wood, cardboard
Foam - flammable liquids
Dry powder - electrical fires
Carbon dioxide - electrical fires
Wet chemical - cooking oil fires
What is a mansafe fall arrest system?
Horizontal or vertical safety lines designed to keep people safe whilst working at height. The user clips onto the line with a harness - providing protection from a fall.
What are Building Regulations?
Regulations to ensure that new buildings, conversions, renovations and extensions are going to be safe, healthy and high performing.
Can you list the Building Regulations Approved Documents?
Part A - Structure
Part B - Fire safety
Part C - Site preparation
Part D - Toxic substance
Part E - Sound resistance
Part F - Ventilation
Part G - Sanitation, hot water safety and water efficiency
Part H - Drainage and waste disposal
Part J - Combustion appliances and fuel storage
Part K - Protection from falling, collision and impact
Part L - Conservation of fuel and power
Part M - Access to and use of buildings
Part O - Overheating
Part P - Electrical safety
Part Q - Security in dwellings
Part R - High speed electronic communications
Part S - Infrastructure for charging elec vehicles
Part T - Toilet accommodation
Approved Document 7 - Materials and workmanship
Who reviews compliance with Building Regulations?
The building control officer or improved inspector
What are British Standards?
Publications issued by the British Standards Institution - they give recommended minimum standards for materials, components, design and construction practices
Can you name some materials which have been banned from use in construction?
Asbestos
High alumina cement
Urea formaldehyde
What is the Equality Act 2010?
Legally protects people from discrimination in the workplace and in wider society.
How does the Equality Act affect buildings?
Whilst accessible design is regulated by Approved Document M, the Equality Act requires ‘reasonable adjustments’ to be made when providing access. This means due regard must be given to specific needs of likely building users. Compliance with Part M does not guarantee compliance with the Equality Act
Can you explain what the Party Wall Act 1996 is?
The Party Wall Act 1996 provides a framework for preventing and resolving disputes in relation to party walls, boundary walls and excavation near neighbors.
The Act is separate from obtaining planning permission or building regulation approval.
What are O&M manuals?
Operation and Maintenance manuals are provided upon completion of the build phase, providing crucial information to the Client/Building owner regarding how the building was constructed, should be maintained and deconstructed.
