Construction Tech Flashcards
What is buildability?
Extent to which design of a building facilitates the ease of construction.
RIBA Stages?
0-7.
0 - Strategic Definition.
1 - Preparation and Brief.
2 - Concept Design.
3 - Spatial Co-ordination.
4 - Technical Design.
5 - Construction.
6 - Handover.
7 - Use.
Off-site vs in-situ construction?
- Safety.
- Efficiency.
- Sustainability.
- Speed.
Building works vs civil engineering works?
Building Works: all buildings.
Civil Eng Works: drainage, highways, bridges, etc.
What are temporary works?
Parts of a project needed to enable work, but not permanent. i.e. scaffolding, hoarding.
What are hoists?
Vertical transportation of materials/people.
What is shoring?
Temporary support to existing buildings/excavations to prevent collapse.
What is a culvert?
Tunnel-like structure, to allow water to flow under roads or other obstructions.
What is a drainage headwall?
Small retaining wall/structure at inlet or outfall of a storm water drainage pipe, to protect end of the drain, and prevent erosion.
What is the substructure?
Portion in the ground, supporting superstructure.
Foundations, basements, retaining walls.
What is ground heave?
Upward movement of the ground, often with clay soil when wet.
Ground improvement techniques?
- Vibro compaction.
- Vibro stone columns.
- Vertical drains.
- Soil mixing.
- Dynamic compaction.
- Dynamic replacement.
Forms of excavation?
Site clearance.
Stripping topsoil.
Cut and fill.
Foundation excavation.
Factors to consider while excavating?
Nature of the soil.
Method.
Ground support systems.
Existing buildings.
Depth.
Services.
Waterproofing basement techniques?
Tanking - materials applied internally or externally to provide continuous membrane to base slab/walls.
Drained cavity - accepts small amount of water seepage occurs, cavity walls formed and water is pumped/drained.
SUDS?
Sustainable Urban Drainage Systems.
Manage stormwater locally, mimicking natural draining.
Detail a typical road build-up please?
From bottom to top:
- compacted subbase.
- base course.
- binder course.
- wearing/surface course.
What is a foundation?
Supports superstructures, transferring load to the ground.
Foundation considerations?
Load of the building.
Capacity of the ground.
Structure type.
Cost.
Constraints.
Types of foundation?
Strip.
Pad.
Raft.
Piled.
Raft foundation?
Continuous slab, spread over large area.
Pad foundation?
Support individual columns, square or rectangular.
Strip foundation?
Strip of linear structure to spread the load, supports masonry.
Pile foundations?
Column extends deep into the ground, for very heavy loads.
Types of piling?
End bearing piles.
Friction piles.
Construction methods of piling?
Bored piles.
Driven piles.
When is piled the best solution?
Very heavy loads with weak soil.
Settlement issues common.
Water table is high.
Non-uniform load distribution.
End bearing vs Friction piles?
End bearing - bottom sits on a strong layer of soil/rock.
Friction - stresses along side of the pile, transfers forces to the soil.
Bored v driven piles?
Driven is manufactured off site, bored is made on-site.
Pros and cons of driven piles?
Pros:
- Precast to required spec.
- Any size and shape can be made.
- Driven in compacts soil nearby.
Cons:
- Requires heavy equipment.
- Increased noise and vibration.
- Costly if mistakes are made.
Pros and cons of bored piles?
Pros:
- Any size or shape can be formed on site.
- No risk of damage during delivery.
- Reduced vibrations.
Cons:
- Wastage is generated to be handled.
- Relies on multiple trades.
- Do not improve load bearing of ground.
What are secant pile walls?
A wall of interlocking piles to make a solid barrier.
What is underpinning?
Repair and strengthening of existing foundations.
Needed due to erosion, vibration damage, increase load bearing.
What is superstructure?
Above ground level structure. i.e. walls, slab, columns.
What is the envelope of a building?
Boundary between interior and exterior of building.
Key considerations of external walls?
Weather protection.
Fire resistance.
Appearance.
Lifespan.
Maintenance.
What is a retained facade?
Facade of a building is preserved while the rest is remodelled.
Standard UK brick dimension?
215 x 102.5 x 65 mm.
How many UK bricks per m2?
60 bricks.
How many UK blocks per m2?
10 blocks.
What are weep holes?
Openings in outer skin of masonry, providing ventilation.
Two types of brick bond?
English Bond - Alternating headers and stretchers.
Stretcher bond - most common, vertical joints staggered each time by half a brick.
What is a curtain wall system?
Usually, lightweight aluminium frame where glazed or opaque panels are fixed.
What are movement joints?
Absorbs expansion/contraction of materials.
Wet rot vs dry rot?
Two types of fungi, 20% moisture vs 50% moisture.
Characteristics of wet rot?
Spongy to the touch.
Darker timbers.
Localised.
Damp smell.
Characteristics of dry rot?
Dry and brittle.
Orange spore dust.
White strands.
Rusty brown.
Main components of concrete?
Cement.
Aggregate.
Water.
Dead loads vs live loads on a structure?
Things that are part of the structure vs things that are moveable like people and furniture.
What are retaining walls?
Wall that holds back the soil behind it.
Pre-tensioned concrete?
Tendons or cables are stretched across concrete formwork before placing concrete.
Released after hardening.
Post tensioned concrete methodology?
Cast around tubes which contains reinforcing tendon.
The tendons are threaded through ducts using jacks.
What is a glulam beam?
Glue-laminated timber. Multiple layers of wood bonded with adhesive.
Reinforced concrete?
combination of concrete with reinforcements like bars, rods and mesh.
Advantages of timber frames?
Can be faster vs concrete.
Lightweight structure.
Aesthetically pleasing.
Sustainable.
Disadvantages of timber?
Skilled workmanship required.
Potential for rot.
Fire protection needed.
Advantages of steel frames?
Faster than concrete.
Recyclable.
High weight to strength ratio.
Disadvantages of steel frames?
Lower load against concrete.
Fire protection required.
Steel prices volatile.
What is a portal frame?
Beam supported at either end by columns.
Advantages of concrete frames?
Inherent fire protection.
Cladding fixed direct to the frame.
Sound and heat insulation.
High strength.
Disadvantages of concrete frames?
Require formwork.
Slower on-site construction.
Bulky structure.
With reference to concrete frames, what is formwork?
Structure used to contain concrete and mould it.
Considerations when selecting type of structural frame?
Programme.
Fire protection.
Acoustic/thermal.
Market conditions.
Site logistics.
User requirements.
BREEAM.
Future expansion.
What is slipform construction?
Pouring concrete into the top of continuously moving formwork.
What is jump forming?
Works similarly to slipform. Jumps to next section instead of constant movement up.
Key considerations when constructing internal partitions?
Fire rating.
Acoustic/thermal.
Doors/windows.
Strength.
Height.
What is a CAT A fit out?
Provided basic level of finish. Blank canvas for interior and office designers.
What is a CAT B fit out?
Provides space ready to use and operate in.
Common types of plasterboard?
Standard (white/grey)
Fire boards (pink)
Acoustic boards (blue)
Moisture resistant boards (green)
What is raised access flooring?
Floor sitting on pedestals above the slab, allows services to be located in the void.
Difference between single phase and three phase electrical supplies?
Single phase is 1 live wire, 3 phase is 3 live wires. 3 phase is better.
Why do we install generators in addition to grid power?
As back-up usually diesel powered.
What is a UPS?
Uninterruptable Power Supply - installed in critical areas like hospitals and data centres.
What is HVAC?
Heating, Ventilation, and AC.
What do FCU, AHU and VAV stand for?
Fan Coil Unit.
Air Handling Unit.
Variable Air Volume system.
What is natural ventilation?
Method of supplying fresh air to a building or room by passive forces.
What is mechanical ventilation?
Fan driven flow of air outdoors to inside.
What is an air source heat pump?
Takes heat from the air and boosts it to higher temperature by compressor.
What is a siphonic drainage system?
Contains anti-vortex plate which acts as a baffle and prevents air from entering piping.
Water is sucked or siphoned from the roof into the drain at high speed.
Lack of air improved the speed of drainage.
What is rainscreen cladding?
Uses exterior surface to break sideways rain, to reduce momentum of water.
Not waterproof but helps the building.
What is a parapet?
Extension of external building above roof level. Used as edge protection.
Difference between Gable, Hipped and Mansard roof?
Gable - Sloping downward in tow parts from centre.
Hipped - slopes from all sides with no vertical ends.
Mansard - steep pitch with a shallow pitch or flat roof on top.
What site surveys may be required for a project?
Tag and trace.
Topographic.
Site investigation.
Asbestos.
Utility searches.
Ecology surveys.
Archaeological.
Objectives of a site investigation?
Establish parameters for foundation/substructure.
What is a CBR test?
California Bearing Ratio.
Tests load bearing capacity of the ground.
What types of vegetation can cause issues for construction?
Japanese knotweed.
RICS guidance on Japanese knotweed?
Japanese knotweed and residential property 2022.
What fire safety provisions may you find in a new building?
Max occupancy.
Fire evacuation.
Fire extinguishers.
Fire alarms.
Sprinklers.
Fire rated roller shutters.
What is a fire compartment?
Divides structure into compartments to limit the spread of fire and smoke.
What is intumescent paint?
Passive fire protection. Expands to protect the surface when heated.
What are automatic fire sprinklers?
Heat activated. A solder link will melt or glass bulb shatters to activate the sprinkler.
Different types of fire extinguisher?
Water - wood.
Foam - flammable liquid.
Dry powder - flammable liquid/electrical.
CO2 - electrical.
Wet chemical - cooking oil.
What is a mansafe fall arrest system?
Horizontal or vertical safety lines to keep safe while working at height.
What are building regulations?
Regulations to ensure new buildings are 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.
Part H - Drainage and waste disposal.
Part J - Combustion appliances.
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 communication networks.
Part S - Infrastructure for charging electric vehicles.
Approve Document 7 - Materials and workmanship.
Who reviews design and construction phases for compliance with Building Regs?
Building control officer or approved inspector.
What are British Standards?
Publications issued by British Standards Institution (BS).
Name materials banned from construction use?
Asbestos.
High alumina cement in structures.
Urea Formaldehyde.
What is the Equality Act 2010?
Legally protects people from discrimination in the workplace and society.
Disability, race, sex, pregnancy, religion etc.
How does the Equality Act affect buildings?
While the accessible design of buildings is in Part M of Building Regulations, the Equality Act requires adjustments are made to provide access to goods, facilities and services.
What is the Party Wall Act 1996?
Provides framework for preventing and resolving disputes in relation to party walls. Separate from planning permission.
What is an O&M manual?
Operation and Maintenance Manual.
Contains information on the building construction, maintenance, cleaning and decommissioning.
Name some different types of glazing?
Laminated.
Tempered.
Clear.
Single, double, triple.
Benefits of pre-fabrication and examples?
H&S, time on site, cheaper, specified to requirements.
Modular building elements, multi-faith pods, piling, bathroom pods.
Name 3 sustainable construction methods?
SUDS.
Green roofs.
Electric plant vehicles.
Solar power.
Rainwater harvesting.
What is a pile cap?
Spreads the load by use of a single slab on top of piling.
What is the make up of a green roof?
Soil and materials that are permeable, to reduce the risk of flooding and absorb rainwater.
Top-down vs bottom-up construction methods?
Top down involves completing each layer from top to bottom.
Bottom-up involves excavating the entire area before building the foundation from the lowest level.
What is a CFA pile?
Continuous Flight Auger Piling involves a drill that is hollow, and puts concrete into the ground as the hole is drilled.
What is a typical rate for Concrete?
£100 per m3 of concrete. Can vary between £80-£120 depending on location and currently inflation rates.
What is a typical rate for Steel?
At Heathrow a typical benchmark for steel is in the range of £9k-10k per tonne, however this can vary depending on the steel and usage. The steel at Heathrow is more expensive than what would be typically cheaper.
What is RAAC?
Reinforced Auto-Enclaved Aerated Concrete:
Much weaker and commonly used between 1950 and 1990, a health and safety hazard s a result.
