Con Tech Flashcards
Types of piling
- Driven
- Bored
(Friction & End Bearing), - Contiguous & Secant piles
- Sheet
Driven piling
- Piles are pre-cast (typically concrete) and are hammered into the ground.
- Pros; Pre-formed so are good quality. No excavation required.
- Cons; Vibration and noise with bigger machinery (than bored) required so may not be suitable for dense, city-centre sites.
Bored piling
- Bored piling is where the earth is removed,
- formwork is placed
- concrete replaces the void to form the pile.
- Pros; No vibration as the spoil is removed rather than displaced.
- Cons; Excavated material needs to be removed.
- Formwork is required.
Contiguous piling
- Piles are closely placed to form a retaining wall or basement. S
- Secant piles are initially placed with male piles that are reinforced then female piles fill the gaps.
- After subsequent completion the piles are sprayed with concrete to form a continuous wall.
- Contiguous piles are used where the ground is strong enough to be supported by the spaced piles (i.e. gaps are left between them).
- Secant piles require typically twice the amount of piles and therefore are more expensive and time consuming to place
Basement tanking
- Tanked Internally – Applied between the external and internal wall and within the ground floor slab. If penetrated, the inner wall will have to be removed in order to fix the tanking. Water is retained within the external wall.
- Tanked Externally – Applied to the external wall and within the ground floor slab. The tanking can be penetrated when backfilled. This will leak water into the basement; in order to fix the leak excavation will be required to reach the leak.
- Waterproof - Water resistant concrete structure for both external wall and ground floor.
- Drained - The water passes through the external wall into a drained and ventilated cavity which is drained away.
- The basement may use a sump pump to pump the water out of the basement. The pump will be required to run 24/7.
Top Down Construction
- Permanent retaining walls to perimeter; contiguous or secant piling
- Foundations for columns are formed
- Upper most slab is formed
- Work goes down to bottom
Bottom up construction:
- Perimeter retaining walls
- Temporary structural support required to retaining walls
- Excavate just below lowest basement level
- Construction works up from the bottom
- Open to elements / programme impact from weather
Types of frame
- Portal frame,
- steel frame,
- concrete frame,
- load bearing masonry
Steel frame
- Cladded and floors are often pre-cast concrete slabs.
- Steel frames can’t be adapted on-site and require
- high levels of fire protection.
Not used in warehouse as span is limited - portal frame - Pros; Fast to construct,
- factory quality
- castellated beams for M&E to pass through.
Cons; - Poor fire resistance.
- Long lead times.
- Specialist labour for erection.
Concrete frame
- In-situ or pre-cast.
- Core/s will be built first (if steel frame).
Pros; Fire resistant,
- good heat and sound properties.
- Adaptable on site and is
- not prone to long lead in times.
Cons;
- Labour intensive (H&S).
- Temporary formwork.
- Quality issues from weather & labour quality.
- Services have to be drilled through
Load bearing masonry frame
- Traditional form of frame which comprises of
- brick/block cavity walls from the ground floor slab upwards.
- Held together with wall ties and
- filled with insulation in the cavity area.
- Concrete planks or timber beams typically make up the upper floor and this process continues level upon level.
- Typically only up to 3 or 4 stories.
Prefabricated structures MMC
- Constructed in factories off-site and then are transported to site to be constructed.
- Ideal for repetitive structures such as residential, hotels and offices.
- Concrete cores and foundations need to be built before any pre-fabrication work can commence.
- Pros; Programme gains can be significant (certainty, not subject to weather, less waste),
- quality is good,
- good safety as less people on site.
- Cons; Larger or individual (not square!) buildings make prefabrication difficult as efficiencies cannot be realised due to transportation.
- Offsite production must be perfect or entire process can be undermined (re-building aspect may lose any gains on programme and the process is more expensive than onsite construction).
- Only more economical if programme gains are achieved i.e. reduced financing, site preliminaries, increased certainty of achieving pre-let dates e.g. Student accommodation etc. 2 month delay = remainder of the year revenue is lost
Types of MMC
- Modular - e.g. Urban Splash entire floor GF - FF - 2F
- Panelised; sections of external wall put together
Building regulation
- Ensure minimum standards for design and construction within domestic, commercial and industrial buildings.
- Ensure safety of people in and around buildings,
- maximise energy and efficiency and
- facilitate access for disabled people.
- Part A: Structure
- Part B; Fire safety
- Part L; Conservation of fuel
Part A: Structure
2.2 Part B: Fire safety
2.3 Part C: Site preparation and resistance to contaminants and moisture
2.4 Part D: Toxic substances
2.5 Part E: Resistance to the passage of sound
2.6 Part F: Ventilation
2.7 Part G: Sanitation, hot water safety and water efficiency
2.8 Part H: Drainage and waste disposal
2.9 Part J: Heat producing appliances and Fuel storage system
2.10 Part K: Protection from falling, collision and impact
2.11 Part L: Conservation of fuel and power
2.12 Part M: Access to and use of buildings
2.13 Part N: Glazing - Safety in relation to impact, opening and cleaning (withdrawn)
2.14 Part O: Overheating
2.15 Part P: Electrical safety
2.16 Part Q: Security - Dwellings
2.17 Part R: Physical infrastructure for high-speed electronic communication networks
2.18 Part S: Infrastructure for the charging of electric vehicles
2.19 Regulation 7: Materials and workmanship
Permeable paving
- Allows water to pass through the gaps between the blocks.
- The water goes through the subbase which also slows down the water accessing the ground.
- Pros; Managing runoff
- Decreases the total amount of runoff leaving a site
- Cons; Must be used in conjunction with other SUDs (unable to manage storm runoff volumes).
- Expensive over standard asphalt roads.
- Require frequent maintenance.
SUDS
- Sustainable Urban Drainage Systems are a drainage system that reduce natural drainage and run-off water, which
- reduce the environmental impact from surface water drainage
- Permeable paving
- Swales
- Green roofs
- Rainwater harvesting
Attenuation tanks -
- Underground surface water storage tank for when flooding occurs resulting in high amounts of water passing through system to control/ limit the outflow into the mains drainage system
