Flashcards
Construction Technology
Cards in this deck (61)
- 1Tell me about reinforced concrete roof slabs?formed and sitecast - same as a concrete floor
covered by memebrance
sloped for draiange
supported by concrete columns/bearing walls of reinforced concrete/masonry
the edge of the concrete can be trated in 3 ways:
a) an upturn edge beam can create up-stand
b) cantileivered = overhang
c) spandrel beam can support non-load bearing curtain wall - 2Give examples of what is tested in pile load tests?Stress tests = maintained load test; lateral load test
Strain test = low and high strain tests - 3Why do you carry out pile load tests?Determine the soil data so piles can be designed
confirm pile length and cost certainty
determine load-settlement behavioral of pile
verify structural soundness of pile - 4What are the four main types of pilesa) Driven (pre-cast) cast offsite and driven in by machine
b) Driven (in-situ cast) casing driven in, pluged, can cast by removing or retain casing
c) Bored (pre-cast) a bore is made and soil removed, a pre-cast pile put in place
d) Bored (in-situ cast) a bore is made, soil removed, pile cast at site in bore - 5What things should be considered with the installation of driven piles?available overhead space on site (height of pile + hammer)
availability of cranes
noise restrictions to site - 6What are the methods of pile driving?Jacking (only micro piles)
Hammer
vibration - 7What are the advantages of driven piles?1. not affected by ground water
2. driven to long depths
3. can withstand bending and tensile stress
4. good for marine structures
5. not liable to squeezing - 8What are the disadvantages of driven piles?1. risk of breakage during driving
2. may suffer unforeseen damages = reduced capacity
3. cannot be driven if there is low headroom
4. high levels of noise and vibration
5. displacement of soil may lift other piles - 9What are the advantages of insitu cast driven piles?1. not liable to squeezing/ necking
2. can withstand bending and tensile stress
3. not affected by ground water
4. good for marine structures
5. driven for long lenghts - 10what are the disadvantages of in-situ cast driven piles?1. may break during installation
2. may suffer unseen damage
3. may break during driving
4. cannot be driven with low headroom
5. displacement of soil may lift other piles
6. noise and vibration - 11what are the advantages of bored (pre-cast & insitu cast) piles?1. lenght can be varied to suit strutum
2. rock + soil removed and can be inspected
3. installed to long lenghts
4. can be installed to place with low headroom
5. drilling tools can break up obstructions
6. very large bases can be formed in good ground
7. no ground heave
7. lower noise and vibration - 12What are the disadvantages of bore (pre-cast & insitu cast) piles?1. liable to squeezing and necking in soft soils
2. concrete cannot be inspected
3. cannot be ext above ground water level
4. special techniques required for water-bearing soils - 13What is the function of a roof?shelter the interior spaces of the building
- 14What type of roof slopes exist?Flat and sloping roofs
- 15Tell me about flat roof structures1. require continuous membrane roofing material
2. min slope 1/4" per foot
3. slope achieved by inclining the structural members of roof deck or tapering the layer of thermal insulation
4. the slope leads to internal drains
5. can be structured to be used as an outside space
6. the structure of a flat roof may consists of a) reinforced concrete slab or b) timber or steel trusses or c) timber or steel beams and decking or d) wood or steel joists and sheathing - 16Tell me about sloping roof structures?categorzied into either low or medium to high slope roofs
the slope affects the roofing material
low slopes = require roll/continuous membrane roofing shingles and sheet
med-high = may be covered with shingles/tiles/sheet material
sloping roof shed rainwater easily to gutters
the height + area of roof > with horizontal dimensions
the space under the roof can be used
can be combined to a variety of roof forms
sloping roof structures can with be: a) timber/steel rafter and sheathing; b) timber/steel beams, purlins and decking or c) timber / steel trusses - 17How do you estimate the capacity of a pile (two tests)Field approach = a test pile and load test - give a realistic estimate of the pile capacity
Theoretical approach = calculated using formulae - 18tell me about pre-cast concrete roof systems?similar to pre-cast floor system
site cast concrete topping - reinforced can be sloped for drainage
underside of slab may be painted or a ceiling attached
Bearing walls:
either
a) sits onto bearing walls (bearing strip) and ext reinforced dowels from wall into concrete topping or
b) welded and bolted together
end wall:
hooked bars into slab end slot
the roof can be catileivered - 19Tell me about structural roof framing?a) primary and secondary roof beams can support open webb joists/metal decking/insitu cast or pre-cast concrete slabs
b) roof overhangs can be achieved by extending the secondary roof beams they can be tapered or lightened with cutouts
c) the steel can also be used to frame slopes - 20Tell me about rigid frame construction1. they consist of two columns and a beam/girder that are rigidly connected at their joints.
2. typically one storey for light-industrial bdgs/w.houses etc.
3. channel/z purlins (run across roof)
4. channel/z girts (span walls)
5. frames spaced 6100 to 7315
6. typically clad with corrugated metal (roof + siding) - 21tell me about steel roof trusses1. fabricated by welding/bolting structural angles and tee together to form the framework
2. members welded/bolted with gusset plate connectors
3. trusses have lateral bracing (perpendicular)
4. M&E services can pass through spaces
5. metals/cement roof decking spans purlins
6. channel or w purlins span roof - 22Name some type of Steel trusses1. flat trusses - parallel top and bottom chord
2. Pratt trusses - vertical web members and diagonal members
3. Howe trusses
4. Belgium trusses
5. bowstring trusses - 23What are space frames?1. a space frame long-spanning three dimensional plate structure based on the rigidity of a triangle.
2. constructed of either steel pipe/tube/chanels/tees/w-shape spans
3. M&E can go through spaces
4. the frame can be left exposed if 6m above floor
5. wood panel sheathing/ metal deck/ cement roof planks
6. sits on reinforced concrete/ masonry bearing walls support along a line
7. also supported at panel points with columns - 24Tell me about BR approved document A?This part covers the loadings on a building, and the construction of the structural elements including the foundations, walls, floors, roofs and chimneys
- 25What is a flat roof?a roof with less than 10 degrees slope
traditionally used in hot climates where water retention is not a problem - 26What structural decks are used in flat roof construction?1. wood panels over wood joists
2. solid wood decking over heavy wood framing
3. insitu concrete slab
4. pre-caset concrete slab
5. panels of wood and fibre bonded together with portland cement - 27what are the drainage requirements for flat roofs?decks must slope towards drainage points
- 28what are the problems with flat roofs?if the slope is too shallow - it will form puddling for long time periods = premature deterioration of roof
- 29tell me about thermal insulation to flat roofs?it can be either
1. below the structural deck
2. between the structural deck and membrane
3. above the membrane - 30what type of flat roof insulation is the image?under deck and membrane
Traditional cold roof - 31what type of flat roof decking is the image?in between the deck and membrane
warm roof - 32What is exempt under the landfill tax legislation?a) Dredging - material removed from water - (only from rivers/harbors or are natural resources such as sand)
b) Mining and quarrying - must be naturally occurring and not have been processed
c) Pet cemeteries - must be solely of a domestic animal - 33What is superstructure?all internal and external structure above the superstructure
made up of primary (ext walls, stairs, roof, structural walls) and secondary (suspended ceilings/ raised floors, balustrades etc) - 34What is the external envelope?the materials and components that for the external shell or enclosure of a building
may be load or non-load bearing - 35What are Building regulations?Approved documents that sets out the minimum performance standards for the design and construction of buildings
supported by App Docs A to P + other codes of practice - 36What are the approved BR documents?A: Structure; B: Fire Safety; C: Site Preparation and resistant to contaminants and moisture; D: Toxic substances; E: Sound resistance; F: Ventilation; G: Hygiene; H: Drainage and waste disposal; J: combustion appliances + fuel storage; K: protection from falling/collision/ impact; L: conservation of fuel and power; M: disabled access + facilities; N: Glazing; P: Electrical safety
- 37What are British Standards?Publications used by the British Standards Institution (BS)
Gives recommendation on min stn of materials, components, design + construction - 38What are International Standards?prepared by International Org for Standardisation (ISO)
complements BS - 39What are the typical components of a site investigation?objective collect + record data to help design+construction
includes anything on adjacent sites that may impact and: boundary fences/hedges; extg trees; size,depth, locations of services; extg bdg + g. water+ soil investigation - 40Tell me about soil investigations?purpose: determine suitability of site for proposed works + determine adequate foundation system
Determine: potential difficulties - 41What are the main site considerations?Access (approached roads etc.)
Storage
Accommodation
Temp services
Plant
Fencing/ hoarding
Safety and Health - 42What is a retained facade?The facade of a building is retained whilst everything behind the front wall is demolished.
Allowance needs to be made for temporary support structure and also cleaning/ restoration works to retained facade. (often listed) - 43What are temporary Works?Temporary works do not normally appear on construction drawings but demonstrate methods that might be appropriate and resources necessary to ensure safe construction i.e. propping
- 44What is Landfill tax?Bought in by Gov in 1996 - to reduce the amount of waste landfilled in the UK and to promote the reuse and recycling of waste and research into waste practices
the tax (HM Customs) applies to all waste dispised of at a licensed landfill site unless specifically exempt
landfill has two rates (2011)
A) lower rate applies to those less polluting wastes listed in the Landfill Tax (Qualifying Material) Order 2011 (£2.5/t)
B) Standard Rate applies to all other taxable waste
(£72/t) - 45What Legislation covers Landfill Tax?The primary legislation on landfill tax and the Landfill Communities Fund is contained in the Finance Act 1996
Also: Landfill Tax Regulations 1996
Landfill Tax (Qualifying Material) Order 2011
Landfill Tax (Prescribed Landfill Activities) Order 2009 - 46What waste applies to what rate under the landfill tax?Unless it is specifically exempt (see section 4), landfill tax applies to all material disposed of:
a) as waste
b) by way of landfill
c) landfill site that covered by a licence or permit under specific environmental legislation - 47What is substructure?all structure below the superstructure i.e. all structure below ground level including ground floor bed
- 48When are piled foundations adopted?A: Low bearing capacity of the soil
B: lack of bearing strata at shallow depths
C: Heavy loads from superstructure (shallow foundations may not be suitable) - 49What are the classifications of piles - BASE ON MATERIAL?BASED ON MATERIAL
a: concrete; b: steel; c: timber - 50What are the classifications of piles - BASE ON MATERIAL?BASED ON MATERIAL
a: concrete; b: steel; c: timber - 51What are the classification of piles - BASED ON METHOD O CONSTRUCTION/INSTALLATION?BASED ON METHOD OF CONSTRUCTION/INSTALL
a: driven/displacement (pre-cast)
b: driven/displacement (insitu-cast)
c: Bored/replacement (pre-cast)
d: Bored/replacement (insitu-cast) - 52What are the classification of piles - BASED ON LOAD TRANSFER MECHANISM?BASED ON LOAD TRANSFER MECHANISM
a) end bearing
b) friction/floating piles
c) bearing cum friction piles - 53What is the classification of piles - BASED ON SECTIONAL AREA?BASE ON SECTIONAL AREA
a) circular
b) square
c) H
d) octagonal
e) tubular - 54What is the classification of piles - BASED ON SIZE?BASED ON SIZE
a) micro piles dia. <150mm
b) small dia. pile > 150mm and < 600mm
c) large dia. > 600mm - 55What is the classification of piles - BASED ON INCLINATION?BASED ON INCLINATION?
a: vertical
b: inclined/ racker piles - 56What type of piling occurs in the image?Large bored piles
- 57what type of piling occurs in the image?driven piling
- 58what are the loads coming onto the piled foundations?a) superstructure loads - dead loads/ live loads/ wind loads/ seismic loads
b) the loads from surrounding soil (in case of seismic event)
c) water loads (if off-shore) - 59Do piles sit in groups?Yes they integrate into pile caps
- 60What are the load carrying mechanisms of piles?a) end bearing cum friction piles = carry vertical compression - from stratum at tip and friction of soil
b) friction piles = carry load by friction
c) end bearing = carry load to end where there is friction
d) all cases = lateral loads taken by surrounding soils - 61What does it mean by the load carrying capacity of the pile?the amount of load the pile can carry
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- Construction Technology and environmental services T013 Flashcards on Construction Technology, created by alison_patey0437 on 14/04/2013.
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