Technical - Construction Technology and Environmental Services Flashcards
What are the RIBA stages?
Royal Institute of British Architects Plan of Work. Gateways to take a construction project from inception through to design, construction and handover.
0 – Strategic Definition
1 – Preparation and Briefing
2 – Concept Design
3 – Spatial Coordination
4 – Technical Design
5 – Manufacturing and Construction
6 – Handover
7 – Use
What is buildability?
The extent to which the design of the building facilitates the ease of constructing it.
What are the benefits of off-site construction over in-situ?
Modular products can be made, reducing waste.
Not hampered by weather.
Speed – components built off site at the same time can be transported to site and erected at a faster pace.
What are temporary works?
Temporary works that facilitate the permanent works being completed, such as scaffold, propping, formwork, excavation support, access roads and temp lighting.
What are hoists?
Mechanisms that lift materials or people vertically.
What is substructure?
Lower portion of the building situated in the ground. Transmits the load of the building to the ground. Examples are foundations, retaining walls and basements.
What is ground heave?
Usually clay soil that swells when wet and forces the ground upward.
What techniques can be used to improve the ground?
Vibro compaction and vibro stone columns.
Vertical drains and vacuum consolidation.
Soil mixing.
Dynamic compaction or dynamic replacement.
Name some different forms of excavation.
Site clearance.
Stripping topsoil.
Reduced level dig.
Cut and fill.
Foundations.
What must be considered before excavating?
The soil type and ground moisture.
Method of excavation.
Whether ground support systems are required.
How close are neighbouring buildings.
Depth of excavations.
If there are any buried services or drainage.
How can you waterproof a sub-terranean area?
Tanking – waterproof material such as bitumen is applied to provide a continuous membrane down the walls and to the base.
Drained cavity – water enters but it trapped behind a waterproof cavity. The moisture then seeps to the floor and must be drained or pumped away.
What is SUDS?
Sustainable Urban Drainage Systems. Designed to manage surface water drainage and to mimic natural drainage. Stops the fast release of water into out capacitated sewer systems.
What is a typical road build up?
Compacted sub-base (250mm)
Base course (150mm)
Binder course (100mm)
Surface course (40mm)
What is a typical lime floor build up?
Geotextile
Foamed Glass Gravel
Clip rails for underfloor heating
Geogrid
Geotextile
Lime Screed
What is the purpose of foundations?
To spread the load of the building to the ground and bear the load of the superstructure.
What must be considered when selecting what foundations to use?
Ground/ soil conditions.
The total load of the building.
Type of structure.
Construction constraints.
Cost.
What are the different type of foundations?
Strip, Pad, Raft and Piled.
What is a raft foundation?
A continuous slab that extends over the entire footprint of the building. Spreads the load over a wider area than the other foundations so the stress on the ground below is reduced.
What are pad foundations?
Pads of concrete, or reinforced concrete, that support columns.
What are strip foundations?
Linear foundations usually used to support masonry.
What are pile foundations?
A column that is driven deep into the ground in areas where ground conditions are poor or the loads are very heavy.
Two types:
1. End bearing
2. Friction
Piles can either be bored or driven concrete.
When would a pile foundation be most suitable for a project?
When the structure is heavy and the ground is weak.
If there are settlement problems.
If the water table is high.
If the load distribution of the superstructure is not even.
If there are horizontal forces.
What are end bearing piles?
Bottom of the pile is driven down until it rests on a strong layer such as rock. The load then transfers through the pile and onto the rock.
What are friction piles?
Do not rest on a strong layer, instead there are shear stresses along the side of the pile that transfer the forces to the soil.
What are bored piles?
A pile manufactured on site.
What are driven piles?
A pile manufactured off site in factory controlled conditions.
What are the advantages of driven piles?
Precast to required specifications.
Can be a multitude of sizes and lengths.
A driven pile can compact the soil as it is forced downward, increasing the bearing capacity.
Fast and neat.
What are the disadvantages of driven piles?
Needs heavy equipment to transport and install.
Installation is noisy and make vibrations.
An expensive mistake if the dimensions are incorrect.
What are the advantages of bored piles?
Can be made on site to any shape and size.
Won’t get damaged during delivery.
Less noisy and vibration than driven.
What are the disadvantages of bored piles?
Need to coordinate multiple trades to be present at the same time.
More waste than driven.
Can’t improve the bearing capacity of the ground.
Never certain of their depth until you start – cost uncertainty.
What are secant pile walls?
Pile foundations are used to make a retaining wall by interlocking them to create a solid barrier.
What is underpinning?
Repair and strengthening of existing foundations.
When would underpinning be required?
Stabilise foundations impacted by settlement, movement, erosion or vibration damage. Or to increase the load capacity and accommodate new, adjoining buildings or adjacent alterations.
What is the superstructure?
The building above ground level – typically above the damp proof course.
What is the envelope of the building?
The external shell of a building between the interior and exterior.
What is a retained façade?
When the front of an old building is preserved but the building behind is remodelled or a new structure is built. Usually applies to listed buildings.
What are the key considerations when designing external walls?
Weather.
Fire.
Structural requirements.
Lifespan and maintenance.
Thermal and sustainable qualities.
Noise control/ acoustic.
Appearance.
What are the standard brick dimensions in the UK?
215mm x 102.5mm x 65mm. Plus 10mm with mortar.
How many UK standard bricks are there in a m2?
60.
What is the standard dimension of a block?
440mm x 215mm x 100mm.
How many UK standard size blocks are required per m2?
10.
What are weep holes/ air bricks?
Small openings in the outer layer of masonry construction. Allows moisture to drain out and are in to ventilate.
Name two different types of brick bond.
- English – alternating courses of headers and stretchers.
- Stretcher – The most common. Vertical joints staggered each time by half a brick.
What is a curtain walling system?
Aluminium frame onto which glazing can be fixed.
What is a movement joint?
It absorbs the expansion and contraction of the construction materials.
Why are movement joints needed?
Buildings move and if there’s no flexibility then the forces will impact on each other and the building will break.
What are the main components of concrete?
Cement
Aggregate
Water
What is a dead load?
Static forces that remain constant – like the construction materials.
What is a live load?
Things that have weight and can be easily moved in a building – people, furniture, equipment.
What is a retaining wall?
A wall that holds back a load, typically soil. So the pressure of the soil behind the wall is transferred to it and doesn’t spill forward.
What is reinforced concrete?
Concrete that usually has a steel element added to it. The combination of both materials make it stronger and able to take heavier loads.
What is pre-tensioned concrete?
The reinforcement is stretched across the formwork before the concrete is poured. When hardened, the tension is released and transferred into the concrete giving it a greater compressive force.
What is a glulam beam?
Glue laminated timber. Multiple layers of solid wood bonded together with a strong adhesive to make a structural beam.
What’s are the advantages of timber frames?
Faster to erect than concrete.
Relatively lightweight.
Looks good.
Sustainable if grown and harvested responsibly.