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243 Cards in this Set
- Front
- Back
The Building Process from Idea to Reality 12 steps |
Owners Idea/Need • Select Design Professional(s) – Prime Consultant • Develop Building Concept • Request for Proposals • Feasibility Study • Assemble Design & Engineering Team • Building System and Material Selection • Design and Coordination • Develop Contract Documents – Drawings, Specifications, Contract • Building Official(s) Compliance Review • Contractor Selection/Bid-Tender • Subcontractor and Supplier Selection |
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The Design Team 5 |
ArchitectCivil Engineer (Water/Sewer) Landscape Designer/Architect Electrical EngineerMechanical EngineerStructural Engineer Other Professionals |
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What does the design architect or engineer do? |
Translates owner's building ideas and needs into a complete design. Construction documents fully describe the building to be built, consisting of graphic construction drawings and written specifications. |
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11 Select Considerations for Building and System materials |
suitability of system availability of materials workforce availability construction experience/expertise in area cost desired aesthetics appearance preference building constraints legal limitations required functional performance sustainability |
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What does sustainability mean for building materials? |
"meeting the needs of the present generation without compromising the ability of the future generations to meet their needs." |
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building materials - sustainability - origin and manufacture of building materials considerations |
plentiful? renweable? recycled content? energy expended to acquire? manufacturing pollutants & waste? environmental labels? material life cycle? unhealthy or toxic materials? |
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building materials - sustainability - construction of the building considerations |
energy expended to acquire and install? pollutants generated? waste generated? can it be recycled? |
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building materials - sustainability -building maintenance considerations |
energy use over its lifetime? material impact on indoor air quality? maintenance required? maintenance materials toxic? recyclable? fire & smoke properties? |
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building materials - sustainability - demolition considerations |
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building materials - information resources |
american society for testing and materials american nationals standards institute canadian standards association us bureau of standards construction trade & professional associates material associations - -canadian institute of steel construction -cement association -canadian wood council -canadian sheet steel building institute |
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building constraints 1 |
physical limitations: -available land -soil bearing capacity -structural span limitations -building material performance |
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building constraints 2 |
budget |
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building constraints 3 |
legal restrictions |
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zoning ordinances constraintes |
generally imposed by local authorities typically govern -property use, types of activities -size, setbacks, appearance, viewplanes -access, parking -construction activites -land use bylaws -available at planning dept. / inpector -who generally enforces compliance? |
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zoning regulations 1 |
types of allowed activities, such as industrial, commercial, residential etc. |
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zoning regulations 2 |
how much land may be covered by buildings
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zoning regulations 3 |
distance from buildings to property lines |
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zoning regulations 4 |
parking requirements |
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zoning regulations 5 |
building height and area |
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zoning regulations 6 |
special fire district requirements |
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zoning r1-A Halifax Peninsula Single Family Zone 27 (1) The following shall be permitted in any R-1 zone |
a) a detached one family dwelling house b) the office of a professional person located in the dwelling house used by such professtional person as his private residence eg. a home occupation c) a public park or playground d) church or church hall e) a day care facilility for not more than 15 children in conjunction with a dwelling f) a special care home containing not more than ten persons including redient staff members g) uses accessory to any of the forgoing uses |
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r2 |
general residential |
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r2t |
townhouses |
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r3 |
multiple dwelling |
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rc1 |
neighbourhood commercial |
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rc2 |
residential/minor commercial |
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rc3 |
high density residential/minor commerical |
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c1 |
local business |
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c2 |
general business |
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c3 |
industrial |
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c6 |
adult entertainment |
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p |
park and insitutional |
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b |
bakery |
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u1 |
low density university |
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cfb |
canadian forces base |
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moral building codes |
standardized codes, adopted and put into legal effect by local jurisdictions Canada: national building code of Canada US: - inernational building code IBC --international residential code IRC |
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purpose of building codes (part 4 vs part 9) |
...establish minimum construction standards for the protection of life, health, and welfare of the public |
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part 4 vs part 9 |
-part 4 is mostly used for structural design, but part 9 houding and small buildings can sometimes be applied |
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part 9 housing and small buildings |
applies to all buildings of 3 storeys or less in building height and having a building area not exceeding 600m2 and used for major occupancies classified as residential occupancies, businesses, and personal service occupancies, mercantile occupancies, or medium and low-hazard industrial occupancies. |
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the national energy code for buildings |
provides minimum requirements for the design and construction of energy efficient buildings and covers the building envelope, systems and equipment for heating, ventilating and air conditioning, service water heating, lighting, and the provision of electrical systems and motors. It appliles to new buildings and additions. It does not apply to farm buildings nor to housing and smaller buildings covered in part 9 of the national building code of canada.. |
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nova scotia building code act scopeq |
regulations apply to the admisisteration and enforcement of the building code act in the design, construction, erection, placement, and occupancy of new buildings, and the alteration reconstruction, demolition, removal relocation, occupancy and change of occuplancy classification of existing buildings and to the work necessary to correct unsafe conditions in existing cuildings reported to the authority having jurisdiction or oberved during and inspection |
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The work of the construction professional - providing construction services Allocation of responsibilities among major parties |
design team, construction team, owner team |
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design |
architects, engineers, and other consultants |
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construction team |
general contractor, subcontractor, suppliers |
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owner team |
owner, financers, user groups |
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building contract documents - specifications |
clear, concise, comprehensive, divided into trade sections (masterformat), nomencalure should be well known technical or trade terms and standard abbreviations (CSA, ASTM) |
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building contract documents - drawings |
clear, concise, comprehensive, dimensioned, numbered and dated. A list of drawkings should be provided by means of a cersheet of list in the specifications |
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contract documentation format - (construction specifications canada CSC masterformat) |
outline for construction specifications often used by contractors for construction cost coding 50 divisions - each with a multitude of sub-divisions |
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national master specification (NMS) |
the national master specification is a comprehensive text base, containing descriptions of every procedure, product or method likely to be encoutered. this collection of specifications can be used in developing a project specification by editing contents to suit the requirements of a project. |
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the nms has been developed |
by public works and government services canada within the national master specification secretariat. (NMSS) |
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the nmss consults |
the design and construction industry on technical improvements to the text and specifications |
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the nmss has been available to the |
Canadian construction industry for over 25 years and it is the nmss that ensuress the product is available in both englislh and french
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the nmss is in the process of |
greening all of the sections to ensure that they include environmentally responsible material and work practices |
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the building process from idea to reality |
startup meeting - project manager construction scheduling beginning construction shop drawking reviews site meetings (general contractor, project manager, design team, subcontractors, owner's representative) change orders, site instructions ccompliance inspections/reviews |
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construction concerns |
division of work between the shop and the building site optimum use of the various building trades sequencingg of construction operates for maximum productivity cconvenient and safe worker access to contruction operations dealing with inclement weather making building components fir together aand quality assurance in construction materials and componettns through grading, testing and inspection |
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managing construction - what does the general contractor do? |
overseas construction controls the project site managews trades and supplliers coordinates communincations between contruction team and owner, designer |
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construction schedules |
the desired duration of the contruction work may be stated in the bid documents along with milestone dates *scheduling the actual work to meet these requirements is the responsibility of the contractor |
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Addenda |
extreme care must be taken that all bidders are basing their bids on the same information. No new information can be issued even when questioned about the document except by written addenda to all bidders |
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construction scheduling - gantt charts |
represent project tasks or phases on a horizontal timeline provide an easy to understand picture of a project chedule and relationships between phases |
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who is primarily responisble for construction methods? |
the contractor shall be solely responsible for and have control over means, methods, techniquies, sequences and procedures and for coordinating all portions of the work under the contract (unless instructed otherwise.) |
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contruction standards |
define good practice eensure minimum quality eencourage standardiztion and efficiency in methods |
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contractor/supplier selection - bid call |
public advertisement (newspaper,, trade, publ.) ddirect invitation ppre qualifictation process with applicants notrified in the news papers and trade publications |
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an advertisement should include |
owners name location and general description of the work time and place for the receipt of bids location and conditions of the bid documents |
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soils and foundations |
-soil types --soil investigations (testing bore holes, reports) -settlements -site considerations and selection -excavation --compaction and compaction testing -sheet piling --rock excavation --deweatering |
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types of soil and distribution |
-structural properties/characterstics --rarely one type often a micture and/or different "strata" --distribution of soil type and particle size |
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structural properties/characteristics |
-particle size --drainage/water retention --cohesionless to cohesive |
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distribution of soil type and particle size is important inpredicting what? |
-load bearing capacity --soil stability --drainage characteristics |
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who needs to know soil properties/characteristics? when do they need to know them? if an engineer is generally responsible for foundation design, why does a contractor care about the soil on site? |
particle size (influences equipment selection, productivity) drainage/water retention (impacts site accessibillity & conditions) cohesiveness (affects equpiment selection, productivity, volume of excavation and/or backfill) |
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how is that knowledge obtained? |
-common on projects with high loadings --bearing capactiy (#blows/unit(ft)) --soil strata & water table data --soil samples & testing) -sample holes strategicially located --information used to prepare soils report |
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bore hole log - how to read? |
find |
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soils report |
review ex |
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load bering capactity |
review table |
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foundation requirements |
-safe against stuctural failure -technically & economically feasible --settlement not impairing fuction |
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site considerations |
how will sire be accessed? how big is site with respet to the structure? (unrestricted site - area suffienciently larger than the building footrprint, restricted site - area constricted//limited) hhow much excavation will be required? wwill there be any blasting or rock breaking? are site materials suitable for backfill? will a lot of materials need to be trucked in? |
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site selection - sustainability |
building sites should be selected and developed so as to protect and conserve natural habitats and resources to promote biodiversity, to preserve quality open space, and to minimize pollution and unnecessary energy consumption. |
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excavation range |
very little: good soil & shallow foundations cconserdiable: poor soil &/or deep structure |
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unforseen/differing conditions |
-water table --rock//boulders --unsuitable material |
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other common excavation & backfill problems |
weather ssite access operations - excavation & backfill |
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earthwork - unites of measure |
excavation & backfill: cubic yards or meters ggrading: feet squared or meters |
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major productivity issues |
-type of operation (travel distance/confined space) -type of material (soil materials) -material transportation -excpected environmental conditions |
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bucket load capactity (BCM) |
bucket load (BCM) -- capactity x fill factore x load factor |
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unrestriccted site |
-bench and/or angle of repose -must have permiter clearance -considerations (bank erostion, water diverstion, safety, sotrage of backfill & cost) -most likely - least expensive |
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shrinkage factor |
weight/bank unit volume)/(weight/compacted unit weigght) review soil weight change table |
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types of sheeting |
-soldier beams and lagging -sheet piling (wood, steel, precast) -slurry wall |
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braced sheeting types |
-crosslot bracingg -rackers and heel blocks -tie backs draw these |
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steps in constructing a slurry wall |
1. the concrete guide walls have been installed,, and the clamshell bucket begins excavating the trench 2. the trench is dug to the desired depth, with the slurrrry serving to prevvent collapse of the walls of the trench 3. a welded cage of steel reinforcing bars is lowered into the slurry 4. the trench is concreted from the bottum up with the aid of a tremie. The displacced slurry is pumped from the trench, filtered, and stored for reuse. 5. the reinfoced concrete wall is tied back as excavation progresses. |
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rotary drill hole |
draw |
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insert & grout tendons |
draw |
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tendons stressed & anchored |
draw |
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rock excavation |
-sheeting generally not required -blasting _the controlled use of explosives to excavate rock _rock competency and fracture patterns can have a significant impact on the success of a blasting operation -ripping _is a process of braeking up rock and soil with a large tooth or teeth attached to the back of a bulldozer -breaking _done with a hydraulic hammer fitted to an excavator -methods to stablize fractured rock _grout injection __rock anchors |
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what is dewatering |
a process of removing waater and/or lowing the water table within a construciton site |
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what is the purpose of dewatering |
to provide a dry working platform (typically required by code and specification) |
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if the water table is above the working platform, what are the optioons? |
keep water out let water in & remove it combination |
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foundations |
-shallow foundations -deep foundatoins (caissons, piles) -underpinning -retaining walls -shallow frost-protected foundations -foundation design and the building codes |
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what is the purpose of building foundations |
to safely transfer building loads to the ground |
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types of foundation loads |
-dead load -live load -wind load -horizontal pressures below grade -structural member forces -uplift -earthquake |
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shallow foundations transfer load to |
base of structure |
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deep foundations penetrate |
unsuitable soil to reach competent soil or rock |
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primary factors affecting foundation choice |
-subsurface soil -groundwater conditions -structural requirements |
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secondary factors affecting foundation choice |
-contruction access, methods & site conditions -environmental factors -building codes & regulations -impact on surrouding strucctures -construction schedule -construction risks |
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shallow foundation - requirements |
suitable soil bearing capacity undistributed soil or engineered fill |
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shallow foundations - basic types or configuration |
column footings (pad footings)
wall or strip footings |
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stepped strip footings |
draw
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grade beams |
draw |
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deep foundation purpose |
transfer building loads deep into the earth |
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caissons |
similar to a column footing - only deep drilled to required bearing capacity point bearing (exception - socketed) |
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caisson installation sequence |
-hole drilled with a large drill rig -casing installed (typically) -bell or tip enlargement (optional) -bottom inspected and tested -reinforced -concrete placement (& casing removal) |
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two basic type of piles |
end bearing pile - point loading friction pile - load transferred by friction resistance between the pile and the earth |
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pile material |
-steel; h-piles, steel pipe -concrete; site cast or precast -wood; timber -composite look at pics |
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what is the purpose of test piles |
to determine/confirm installation criteria and the adequacy of bearing capacity |
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test piles |
-drive and load, typically a cluster -drive, cap, cure (both test piles and jacking piles) -load test, days or weeks -can take considerable time |
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pile driver |
massive rig-crane w/leads (guide rails)
logistic and sequence considerations (level site) noise, vibration single acting - lift and drop double acting - seam, compressed air or hydraulics, diesel |
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what are pile caps? |
clusters of two, three, four and nine piles with their concrete caps, viewed from above. the caps are reinforced to transmit column loads equally into all the piles in the cluster, but the reinforcing steel has been omitted here for the sake of clarity. |
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cased piles |
draw |
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uncased piles |
draw |
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augercast piles |
a proper sized hole is drilled with a long auger. as the auger is being removed the hole is injected with a concrete mix. then a reinforcing cage is installed if required. |
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helical piles are a.. |
factory-manufactured steel foundation system consisting of a central shaft with one or more helix-shaped bearing plates, commonly referred to as blades or flights, welded to the lead section. |
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extension shafts, with or without.. |
additional helix blades, are used to extend the pile to competent load-bearing soils and to achieve design depth and capacity |
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brackets are used at the... |
tops of the piles for attachment to structures, either for new construction or retrofit applications. helical piles are advanced (screwed) into the ground with the application of torque. |
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pier |
more often refers to a helical pile loaded in axial compression, while the term anchor more often refers to a helical pile loaded in axial tension. |
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helical piles are designed such that most of the |
axial capacity of the pile is generated through bearing of the helix blades against the soil. |
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the helix blades are typically spaced |
three diamters apart along the pile shaft to prevent one blade from contributing significant stress to the bearing soil of the adjacent blade. |
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significant stress influence is limited to a |
'bulb' of soil within about two helix diameters frrom the bearingsurrface in the axial direction and one helix diameter form the center of the pile shaft in the lateral diretion |
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each helix plade therefore acts |
independently in bearing along the pile shaft |
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what is underpinning? |
a process of strengthening an/or stabilizing the foundation of an existing building |
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reasons why underpinning may be required |
-failure of exisiting foundation -change in building use -new construction adjacent to existing |
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what are the underpinning methods |
-enlarge existing foundation --install a new foundation -stabilize surrounding soil -underpin small sections at a time |
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what are underpinning problems |
-dangerous -temprary support and existing conditions -limited work space, time consuming, expensive |
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what is the design impact of building below the water table |
hydrostatic forces (uplift, pressures, waterproofing) |
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what are the constructtion implications of bulding below the water table |
-dewatering -soil retention |
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what is a retaining wall? |
a wall that holds soil back to create an abrupt change in elevation |
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what are the diesign considerations of a retaining wall? |
-height --soil characteristics -ground water -loading behind the wall -appearance |
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what are the types of retaining wall faulre? |
-wall fracture -overturing -sliding --undermining |
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what are rataining wall design elements to prevent failure? |
-relive h2o presure (for all three types-crushed stone, weep holes) -overturning(cantilievered footing, reinforcing) -sliding(key) |
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shallow frost-protected foundation |
-often used for garages and cottages -typically want a minimum of 12'' of soil above the insulationif you want grass to grow -can be less if gravel or concrete will be placed above he insulati -care must be taken to protect insulation during construction --use of free-draiing granular fill increases protecttion from frost |
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items that increase foundation costs |
-building below the water table -building clsoe to an existing structure --column or wall loads that are too high to be supported on shallow foundations -large brick checks tha significantly icrese the foudation wall thickness -unusual wall or footing sizes that increase formwork -lack of co-ordination between footing locations and underground services --tall walls that need to be backfilled before floor structure is in place to brace top of wall |
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foundation design and building codes |
-allowable loads vs limit states -minimum concrete thicknesses and percentages of reinforcement -minimum foundation wall heights/slenderness -minmum frost coeer |
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foundation must: |
-not exceed soil ebaring capacity -not have settlements that exceed allowable limits -resist sliding -resisting voerturning |
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what is the definition of steel? |
-an allow consisting primarily of iron containing carbon and small amounts of other elements -is is made by oxidizing away impurites in pig iron --the carbon increases the strength, but decreases the weldabillity and ductilit --the alloying elemtns improve the strength, weldability, dictility, and corrosion resistance. |
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four operations required for production of mos metals |
1. mining the ore 2. preparing the ore 3. extracting the metal from the ore 4. refinig the metal |
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ferrous metals comprise three general classess of construcion material |
1. cast iron 2. wrought iron .3 steel |
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cast iron |
2-4 percent carbon -strong in compression -less strong in tension -brittle |
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wrought iron |
-little or no carbon -strong in tension -weaker in compression -malleable |
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steel |
-les than two percent cabon -strong in both tension and compresson -cutile |
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mild steel |
-low carbon steel -most common alloy for modern structural steel -not more than 0.3% carbon -small amounts of other metals improve strength, toughness, and other qualities |
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decreasing percent carbon |
for strength and hardness |
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increasing percent carbon |
ductility and toughness |
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failure types |
-highly ductile factture (necks down to a piont) --up and cone (moderately cutile -brittle fracture (no demoration) |
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ductillity |
ductility is a solild material's abillity to deform under tensile stress iit is an aspect of plasticity-the extent to which a soild material can be plastically deformed without fracture |
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why is a knowledge of ductillity imprtant |
-it indicates the degree to which a structure will deform pkastically before fracture --it specifies the degree of alowable deformations during |
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toughness |
is the ability that a material posesses to absorb energy in the presence of a flaw |
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today most steel is made |
-in mini mills using electric arc furnaces
-steel screp is converted directly to new steel, bpyassing the need to make iron from ore |
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traditional mills |
-recycled content: 25-35 percent -primary prodcuts are flat-rolled in stock, such as steel decking and other sheet products |
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casting |
-as the molten steel begins to solidify, it is cast into shapes ranging from plain rectangles or rounds to more cmplex cross sections, such as beam blanks that approximate hte shape of the finished beam products. -in the continuous casting process, casting begins once the outer shell of the steel mass has solidified, while the other inner portino is still molten |
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rolling mill |
-structural shapes are produced in a rolling mill -prior to rolling the beam blanks are reheated to the necessary temperature. -blanks pass through a series of rollers and are progressively deformed into the desired final shape |
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classes of structural steel |
-plain carbon steel -alloy steel |
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w |
weldable steel -meet specified strength requirements and are suitable for general welded construction where notch toughness at low temperatures is not a design requirement-buildings, compression members of bridges350W |
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wt |
weldable notch-tough steel -meet specified strength and chapry v-notch impact -welded construction where ntoch toughness at low temperature isa design requirement -in addition to specifying gerade must specify required categore that establishes the charpy-v-notch test temperature and energy level -primary tension members in bridges and similar elements |
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r |
atmospheric corrosion resitant steel -meet specified strength requirements -good atmospheric corrosion resistance(better than carbon structural steels) -can be used bare(unpainted) when properaly exposed to the atmosphere -may be welded redily up to the maximum thicnkess covered by standard -unpainted siding, npainted light structural members |
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a |
atmospheric corrosion resistant weldable steel |
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at |
atmospheric corrosion resistant weldable notch-tough steel -meet charpy v-notch requirements -better corrosion resistance than carbon steels -suitable for welded construction(low temp notch toughness) -purchaser must specify category of chapry v notch and energy level -primary tension members in bridges |
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q |
quenched and tempered low alloy steel plate -meet specified strength requirements -are readily welded but must not adversely affect properties of the plate -bridges |
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qt |
quenched and tempered low alloy notch-tough steel plate meet strength and charpyvnotch requirements -good resistance to brittle fracture -suitable for low temp notch toughness -must specify chapry notch v category and energy level |
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notch toughness |
-charpy v-notch test is a high strain test -determines amount of energy absorbed by a material during fracture -is a measure of a given materials notch toughness -a tool to study temperature dependent ductile-brittle transition -widely applied in industry, since it is easy to prepare and cheap |
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csa standards |
???? |
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atsm specifications |
???? |
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steel framing advantages |
-light in proportion to its strength -strong &stiff (span, vertical towers) -quick to erect -precise & predictable material -recyclable |
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steel framing disadvantages |
-tendency to corrode depending on environment -high temperatures (fires) loss of strength |
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W shape designations |
W infront of depth and X infront of weight |
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W shape size range |
depth 106mm-1108mm weight 0.19kn/m-8.66kn/m |
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W shape uses - beams and columns |
proportions-shape tall and narrow - beams square - columns and piles |
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by varying roller sizes and spacings, wights can |
be produced, all nominally 10" in depth |
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Steel angle designations |
L-angle designation first two numbers multiplied-size of legs (mm) last number-thickness of legs(mm) |
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steel angle uses and examples |
uses: short beams supporting light loads ex: lintels, connectors, veneer/skin support, edge support (edge angle), diagonal bracing |
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Channels (C shaped) uses: |
truss members, bracing, lintels |
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Channels (c shaped) designations |
C100x11 c-designation first number-nominal depth (mm) second number - weight (kn/m) |
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hollow structural sections |
-hollow square, rectangular, round and elliptical shapes -made by cold or hot forming seel strip sheet and welding longitudinally -HSS shapes are used for trusses, structurally efficient column sections, and where the simple external profile is desireable |
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stainless steel |
added nickel and chromium forms self-protectnig oxide later that provides long lasting protection against corrosion |
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open web steel joists |
-mass produced steel trusses -common uses floor and roof support -joist spacing depends on load, span capabillity of deck(typically 2 to 10 ft) |
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Spans of different open web steel joists |
K series - up to 18m LH longpsan - to 30m DLH deep longspan - to 44m |
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steel trusses |
-heavier members -can carry larger loads and span greater distances |
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three steel member joints |
rivets bolts welds |
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rivets |
to install heat rivet insert in hole and hammer to produce a second head, cool and expands toform a tight joint
-seldom used anymore labour intensive |
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bolts |
2 types - carbon and high strength carbon similar to ordinary machine bolts, low strength shear connectors high strength has higher shear resistance can also be used in friction connections |
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bolts installation |
drift pins(align) temporary bolts tighten bolts provides a shear resistance |
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high strength bolts friction connections |
-load transferred between members by friction -members clamped together -must be tightened |
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verification of required tension |
-turn of the nut method (tighten until snug then turn an additional fraction of a turn) -tensino control bolts (correct tension is reached when end breaks off load indicator washers or direct tension indicators - protrusions flatten as bolt is tightened |
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welding |
steel surfaces to be joined are heated to a molten state. additional molten metal is added from the electrode. in finished joint, members are fully fused |
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fillet welds |
easy to make, little joint preparation required |
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groove welds |
require properly shaped and spaced joints |
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puddle welds |
fasten metal decking to structural members |
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welding vs bolting (both can achieve similar performance) |
welding -labour intensive, required highly skilled craftsmen, verification/inspection of quality bolting -quick easy and less labour intensive and skill required not uncommon to have both |
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framed connection |
review picture angles, plates, or tees connect web of beam to side of column angles are usually joined to beam in teh fabricators shop. beam/angle assembly is bolted to the column in the field |
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shear connection |
review picture transfers gravity loads from beam to columns not suffienctly rigid to transfer bending forces modeled structurally as if it is free to rotate, or hinged. AISC simple connection----what does this mean?? |
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moment connection |
review picture -transfers gravity loads and bending forces -beam flanges are joined to column -column is reinforced to carry bending forces -beam is restrained from even small rotations -AISC fully restrained--what is this?? |
|
options for building structure lateral resistance |
review pictures -diagonal bracing (or eccentric bracing) -shear panels(walls) -moment connections -combination (common) ---most common bracing and or shea panels with framed connections (bolted-shear) |
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column base plate |
-distribute loads -attachment to foundation often shop welded |
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options for setting column to proper elevtation |
leveling plate -set in grout prior to column erection leveling nuts -nuts set to elevation prior to steel erection shims -metal shims set to |
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instalation sequence for columns |
1. erect columns 2. install beams and girders 3. plumb structure 4. complete(weld or tighten) all connections including diagonal bracing 5. install edge angles & decking (or netting/plank) 6. start next tier |
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edge angles |
-forms the slab edge -anchorage of exterior 'skin' |
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cold formed steel |
formed by rolling or bending sheet steel light steel framin; cshaped is most common -commonly used for parition and exerior wall framing |
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metal decking |
-a sheet of steel that has been currogated to increase its stiffness -span capability primarily based on its thickness(gauge) of the sheet or the depth and bracing of the currogations |
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what are the uses of metal decking |
-permanent formwork for concreate -floors -roofs -roof deck |
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composite metal decking |
-works in combination w/concrete fill -bonds to the concrete -serves as tensile reinforcing -often in combo with shear studs -creates a shear connection between deck & frame -increase carrying capacity -produces lghter stiffer and less costly frame |
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metal decking attachment |
mechanical fastener(self tapping screws) welding (common for floor deck) |
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fireproofing |
codes limit the use of exposed steel how? height and area limitations why? fire/hear reduces yield strength |
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structural steel fireproofing methods |
-encasement with a fire resistant material --concrete or masonry --adds dead weight -plaster --costyly/labour instensive --exterior or humid applications -drywall --also serves as finish mater -spray on fireproofing -cobination -intumescent mastics and paints |
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what is the spray on fireproofing mixture |
cementitious or fiber and binder mixture sprayed to required thickness |
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longer spans |
-rigid steel frames -depth of beams and columns varies with magnitute of bending forces -berwick appledome, summerside credit union place |
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castellated beam |
canadian nation exhibtbion |
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space frame |
three dimensional structure carries loads similar to a two way slab |
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cantilevered beams |
gerber system |
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floor systems |
-steel deck diaphragm -composite -hambro |
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framing |
cantilevered beams floor systems joists joist girders bracing options |
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steel deck diaphram - fluted deck |
-fluted deck is equivalent to the web of a horizontal beam of which the flanges are the perimeter structural members connected to the deck -the span of the horizontal beam is defined by the distance between the vertical lateral load resisting systems connected to the deck -secondary elements form stiffeners for the web produced by the fluted deck. as for normal beams, the deck (web of horizontal beam) must be attached to the perimeter members (flange of the horizontal beam) to ensure transfer of the shear forces review picture |
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composite beams |
-common to have concrete slab supported by steel beams, if these are connected so that they act as one unite it is a composite beam -similar to t beams where the flange of the t beam is made of the steel section -has the advantage that the concrete in the slab takes all or most of the compression (for which it is best suited) while the steel beam takes all the tension |
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hambro floor system benefits |
simple-fast and easy to install rigid-composite design ductable-saves on all mechanical trades(plumbing and mechanical duct openings without fire dampers acoustical properties- STC 57, IIC 20 versatile-applicable to all types of building frames service-velue engineering, design plans, fast, dependeable deliveries economical - lesss concrete and reinforcing steel required reusable forms- reusable plywood forms |
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advantages for joist girders |
-steel used has a yield strength higher than steel used in beams -better cost control for material purchases (angles) on the canadian market compared with importing the beam sections -open web joists girders are lighter than the full web beams of the same depth -the joist girders can be used to facilitae the installation of ventilation ducts and plumbing -the speed and ease of site erection imporves jobsite coordination |
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requirements for economical use of joist girders |
1. longer spans-of joist girders are preferred as this reduces the number of columns inside a building 2. greater depths-reduce the size of the top and bottom chords for increased weights savings 3. bay arrangment-should be repetitive since designing and fabricationg many identical pieces will reduce production costs. 4. regular joist spacing-must be maintainedby the building designer by lining up the joists on either side of the joist girders 5. recangular bays-are recommended, in afoog or floor system using joist girders and joists, where the longest simension corresponds to the joist span, while the shortest dimension corresponds to the joist girder span. an optimal rectangular bay would typically have a ratio of joist span to joist girder span of approximately 1.5. |
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other steel structures |
pre engineerd buildings -butler building -behlen corr-span building -econox portable buildings space frames |
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space frame |
lightweight, rigid, three dimensional structure with interlocking struts in a geometric design - carries loads similar to a two-way slab |
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other considerations of structures |
-floor vibrations -acoustics (steel shapes) -aesthetics (coatings and connections) |
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floor vibrations due to human activity guide |
provides basic principals and simple analytical tools to evaluate steel framed floor systems and footbridges for vibration serviceablility due to human activity and provides guidance on devloping redial measures for problem floors |
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floor vibrations responsibility |
the building designer is responsible for the vibration analysys and must provide the joist manufactureer with the necessay design parameters (minmum inertia or maximum deflection) for joist fabrication |
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floor vibration points |
-floors that may exhibit vibration problems must be evaluated at the beginning of the design process by the building designer -the most efficient method of reducing vibration problems is to increase the stiffness of the floor systems -thicker concrete slas and stiffer beams are more effective than an increase in the joist moment of inertia -this is the major reason why floor vibrations should be analyzed when the structural members are being designed |
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acoustics |
-someimtes additional concrete topping is required on steel deck for acoustical consdierations -the shape of exposed steel may be a conderation. round shapes are more suitable for something like a tv studio. -steel structures have less mass than conrete structures fo if sound separation is a primary consideration (such as a condo building) concrete will likely be chosen over steel. |
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specialty paints |
require more care during the application process, and are moe costly bu provide enhanced protection against corrosion |
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specialty paints - zinc |
provides protection against rust since the zinc acts as an anode to protect steel from corrosion. inorganic zinc primers in one coat applications provide similar rust protection to galvanization. organic zinc primers are generally used in multiple coat systems. |
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specialty paints - epoxy |
two component paints that offer much greater rust protection than standard primer, but less than zinc. create a protective barrier that seal the metal surgace, are very effective i humid environments such as arenas and pools. cost twice as muc has the stard primers due to their higher retail price and thicker coats required |
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specialty paints - polyurethane |
usually applied as a finish coat on the zinc primer or epoxy.
several types can be applied directly to steel without the use of primers. these finishes, which are characterized by their color retention and gloss, are generallly required for exterior environments. polysiloxane combines the properties of both epoxy and polyurethane paints and allows for the application of a single coat. however it costs at least three times as much as conventional plyurethane paint. |
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light gauge steel - CSSBI |
Canadian Sheet Steel Building Institute |
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light gauge steel - CFSEI |
cold formed steel engineers institute |
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CSA Standard S136-12 |
North American Specificatication for the Design of Cold Formed Steel Structural Members |
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light gauge steel framing advantages |
-flexible and easy to install -higher quality/tolerances -dimensionally stable -lighter, stronger -price stability -insect resistant -non-combustible -less waste, recycable |
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light gauge steel framing - disadvantages |
-corrode if exposed to water -previously -not code approved -protection of electrical wiring -isolation of dissimilar materials -thermal transmission -installed cost of steel vs wood -some trades not as familiar with steel framing |
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light gauge steel - manufacturing |
sheet steel is fed from continuous coils though machines at room temperature that cold work the metal and fold it into efficient structural shapes, producting linear members that are stiff and strong -these members are referred to as cold-formed metal framing to differntiate them from the much heavier hot rolled shapes that are used in strucutural steel framing -the term light gauge refers to the relative thinness (gauge) of the steel sheet from which the members are made |
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structural properties light gauge steel |
-are computed in accordance with CSA Standard CAN/CSA-S136-01, North American Specification for the Design of ColdFormed Steel Structurals Members -steel shall meet the requirements of CAN/CSA-s136-01with a minimum yield strength of 33ksi for design thickness less than or equal to 0.0451 and 50 ksi for design thicknesses greater than or equal to 0.0566. |
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builder benefits of steel (there's a lot) |
-steel will not rot, shrink, swell, split or warp and is non combustible. -every steel stud is a good stud. steel framing is of ocnsistent quailty -steel framing can be supplied to the exact lengths required thus eliminating much of the on-site cutting and most of the waste -steel framing is a proven technology that is user friendly allowing for a smooth transition from other materials -steel framing members are available ina avariety of standard shapes and sizes in varying steel thicknesses -steel members weigh as much as 60% less than wood members; therefore foundation and seismic loads can be reduced -steel framing members are manufactured with pre-punched holes for running piping and electrical wiring, minimizing work for other trades -job site scrap has resale value |
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builder benefits of steel (more) |
-steel framing accommodates all types of commonly used finishing materials -the inherent strength of steel can be utilized to reduce the number of framing members required. it is not necessary to replace steel for wood stick-for-stick -steel is competitively priced and consistent in quality. steel prices are more stable than wood and steel supplies have historically been more readily available -steel framing does not dry out and shrink overtime, thus the costly call backs to repair warped walls, nail pops and squeaking floors are eliminated. -buliding waste and pilferge from the construction site is greatly reduced -steel members can easily be prefabricated at the construction site, at a central assembly point near the site or can be assembled in panels at a factory -no heavy equipment is necessary when light gauge steel framing is used |
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environmental benefits of steel |
-all steel products are 100% recylable. the overall recycling rate of steel products in north america is 66% -steel products can be recycled repeatedly without degradation -the steel industry is the single largest recycler in north america -during the last decade, more than 1 trillion pounds of steel scrap have been recycled -magnetic separation makes steel the easiest and most economical material to remove from the solid waste stream -the amount of energy needed to produce a ton of steel has been reduced by 34% since 1972 and continues to decrease |
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steel framing - joining and fastening |
-steel framing procedures are much the same as conventional framing, using similar tools, but with different attachments -the main tools used in steel framing are: tin snips, a screw gun, nibblers, and a circular or chop saw. -construction workers who know how to use a power drill with a sccrewdriver attachment will have no trouble with steel framing assembly -circular chop saws are used for cutting steel by substituting abrasive wheels for wood cutting blades -self drilling screws are the most common fasteners used in steel framing |
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thermal performance |
-steel is very conductive and in cold climates rigid insulation is required on the outside of steel framing to reduce thermal bridging -steel framing typically reduces the in-cavity R-value by as much 50% -wood framing reduces in-cavity R-value<<<what is this? by a bit less than 10% |
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fire resistance |
-steel framing non-combustible but loses strength if exposed to fire. therefore must be protected common methods: -gypsum wall board -gypsum sheathing -plaster |