Construction Tech Flashcards
What are piles
A series of columns constructed or inserted into the ground to transmit a load of a structure to lower level subsoil
Why are piles used?
Piles are used to get to more compact/stronger soil or rock
What are sheet piles?
Sheet piles are interlocking steel sheeting driven into the ground to provide earth retention & excavation support.
Retaining walls/underground structures
Name two different type of piles
Friction - pile transmits load to surrounding soil
End bearing - load-bearing capacity at the toe of the pile on hard layer of rock/dense soil/gravel
What is a raft foundation
Spread loads of superstructure over a large base.
A large base reduces the load
Used for poor soils on lightly loaded buildings / domestic
Can be solid raft slab/beam
Heavy loads can cause raft to move sideways
What is a strip foundation?
Suitable for most subsoils/light structural loadings/domestic dwellings
What are pad foundations?
Suitable for most subsoils except loose sand & gravel
Support localized single-point loads such as structural columns, groups of columns or framed structure
Usually reinforced concrete & square where possible
Steel frame advantages
High tensile strength to weight ratio Not vulnerable to termites or organisms Stable Moisture/temp changes have no impact Consistent design - strict national standards
Steel frame disadvantages
Requires fire protection
Price of steel is variable
Additional cost for labour/due to experience required
Concrete frame advantages
Already fire protected
Good sound and heat insulation
Can do complex geometry
Insitu allows for alteration at a late stage
Concrete frame disadvantages
labour-intensive onsite - high initial costs
Slower to construct onsite than other methods
Timber frame advantages
Thermally efficient
Prefabrication
Less of structural weight-produce savings on foundation design
Timber frame disadvantages
Poor resistance to fire
Poor installation of DPC results in dampness penetrating the timber which can lead to decay
What are the British Standards?
Recommended minimum standards for materials, components, design and construction
What is a Party wall?
- A wall that stands on the lands of 2 or more owners and forms part of a building.
- A wall that stands on the lands of 2 or owners but does not form part of a building, e.g a Garden Wall.
- A wall that is in one owners land but is used by 2 or more owners to separate their buildings.
What act governs Party Walls?
The Party Wall Act 1996.
What are Rights of Light?
A form of easement that allows the existing buildings to maintain the same level of illumination.
What is the construction of a warm flat roof?
Insulation is placed above the rafters which ensure the entire roof structure is insulated, more energy-efficient.
HIgher profile roof
Roof covering, insulation, membrane, decking, joists, ceiling
What is the construction of a cold flat roof?
Insulation is placed in between the rafters.
Roof covering, decking, joists, ceiling
Cold conducts through rafters creating cold bridging.
However lower profile roof
What are the different types of coverings for a flat roof?
- Single Ply membrane.
- Mastic Asphalt.
- Built-up felt.
What is the difference between a warm and a cold roof?
- A warm roof will make the entire building structure warm, in an attempt to avoid any cold bridging.
- A cold roof is where the insulation is placed beneath the roof space, leaving the roof space cold. This will either need to be ventilated or have a breather
What is cold bridging?
A weak spot in the insulation to a building
What types of Piling methods do you know of?
- Driven Piles, also known as displacement piles.
- Bored Piles, also known as replacement piles.
- Secant Piles, used to create retaining walls.
Name some legislation that impacts on design and construction
The Health & Safety at Work Act 1974
The Building Act 1984
The Party Wall Act1996
The Disability Discrimination Act
Name regulations that relate to the Health & Safety at work act in construction
- CDM Regulations 2015
- Control of Substances Hazardous to Health Regulations 2002
- Working at Height Regulations 2002
CDM
When does notification have to be given to the HSE?
If a project lasts more than 30 days and involves more than 20 workers.
What are the building regulations?
A set of standards for the design and construction of buildings to ensure the safety and health of people that must be complied with.
The Building Act
Name some Approved Documents
Part B - Fire Safety
Part L - Conservation of fuel and power
Part M - Access to and use of buildings
What are the British Standards
technical specifications or practices that can be used as guidance for the production of a product, carrying out a process or providing a service
What is Formwork?
• The process of placing temporary or permanent moulds into which concrete is poured.
What is Falsework?
• Temporary support structures used to support formwork.
