exam Flashcards
Mortar Ingredients
portland cement, hydrated lime, inert aggregate, water (ASTM specifications C144 establishes this)
Mortar Properties
- cushions: the irregularieties of each brick
- bonds: into a monolithic structure
- seals: from water and wind from entering
- appearance: of finished masonry construction
Mortar Workability
- Type M: below grade = 2500psi
- Type S: loadbearing exterior = 1800 psi
- Type N: non loadbearing exterior = 750 psi
- Type O: historic restoration = 350 psi
- The lower the psi the easier the workability, therefore chose lower before higher.
Brick ingredients
silica, alumina (clay), lime, iron oxide, magnesia.
Brick forms
cored, hollow, frogged
Brick size
brick: 2 1/4” x 3 1/2” 7 1/2”
mortar: 1/2”
Brick laying orientation
header, stretcher, solider, on edge
splay stretcher, splay header, double bullnose
Brick - overall Style
- runner bond: All stretchers- Common bond: headers every 6th course.
- english bond: alternative course with headers and stretchers.
- flemish bond: alternate each with headers and stretchers.
Mortar - overall styles
weathered, concave, vee, flushed, raked, stripped, struck.
Brick - Spanning Openings
walls must be supported if there is a door/window.
Lintels: a method of support to hold the corbel. options: Steel, brick, reinforced concrete.
Corbel: The triangular area above the opening that needs to be supported by lintels (or it falls)
Copings
(5)
A type of brick that is placed on top of the wall for decorative purposes.
half round, saddleback, double bullnose, bullnose, plinth header, plinth stretcher
Brick Sustainability
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Stone ingredients
igneous, sedimentary, metamorphic
stone - overall style
random ashlar
coursed ashlar
random rubble
coursed rubble
stone - construction ways
stone masonry: humans place stone in mortar
stone cladding: machines attach stone to walls
Stone - sustainabiliy
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masonry Concrete - ingredients
water, aggregate (rock, sand, gravel), portland cement.
masonry concrete - form
solid bricks, hollow units, concrete blocks, larger solid units.
masonry concrete - size
8” x 16”
masonry concrete - decorative
scored, ribbed, ribbed, ribbed, fluted, angular
masonry concrete - spanning openings
lintels:
- wide flange section welded to plate (metal)
- reinforced block bond beam units
- reinforced precast concrete
concrete - sustainabililty
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Steel - ingredients
iron ore, limestone, coal
carbon content:
- cast iron: 3-4% more then steel.
- mild steel: <2%
- wrought: lower then steel alloy
steel - shape/size/weight/thickness
-American standard (S18 x 70)
-wide-flange (W21 x 83)
- wide-flange 2,
- channel angle (unequal legs) (Mc10 x 33.6)
-angle (equal legs) (L4 x 3 x 3/8)
-structural tee (Wt13.5 x 47)
-HSS square/round (HSS10 x 81/2)
Bars: round/hexagon/square no greater then 8”
Plate or Sheet: wider solid shapes. Plate is thicker.
Steel - production
Cast steel: molten steel poured in the mold and then allowed to naturally cool.
Cold-worked steel: bent/rolled at room temperature.
Open web steel joists: truss to support floor and roof decks.
- K series: 60’ span. 8-30” depth.
- LH series: 96’ span. 18-48” depth.
- DLH series: 144’ span. 52-72” depth.
Exam question
- difference between moment and shear
- roles
- draw beam-column moment
- 4 assemblies
- annotate
hi
Steel - stabilizing building frame
- Shear walls: stiffest.
- Braced walls: diagonal crossing in rectangle structure. medium stiff.
- Moment-resistance frame: Less stiff. more for windows. ex: Wainwright building Louis Sullivan.
Where:
- Rigid core: where elevators, bathrooms, and stairs are.
- Rigid platform: stronger then in core.
Steel - fireproofing
Fire-proof Steel column: encase in reinforced concrete, enclosure in metal lath and plaster, enclosure in multiple layers of gypsum board, spray on fireproofing, loose insulating sheet metal enclosure, water filled box column
Fire Proof Steel beams and girders: encase in reinforced concrete, enclose in metal lath and plaster, rigid slab, fireproofing, spray on fireproofing, suspended plaster ceiling, flame shielded exterior spry on fireproofing inside.
Steel construction process - column base
- light column -> welded base plate -> on steel plate
- larger column -> welded base plate -> on leveling nuts
- heavy column -> welded loose base plate –> on grout prior.
Steel sustainability
Manufacture
- Mining: loss of wildlife & pollutes
- Emissions
- Can be recycled or reused
Construction and in service
- Paints and oils: air pollution
- Steel has smaller foundations = less excavation
- Spray-on fireproofing materials = pollute air
- Should be thermally broken and/or insulated
Concrete - ingredients
coarse and fine aggregate, portland cement, water.
aggregates:
- volume: 3/4 of concrete is aggregates
- size particle for strength
- small enough to pass easily between reinforcing bars
- max diameter: thin slab (3/8”), slab and structure work (3/4” - 1 1/2”), massive structure like dams (6”)
concrete - supplementary cementitious materials (various mineral products)
may be added to concrete mixtures as a substitute for som portion of the portland cement to achieve a range of benefits.
Pozzolans:
- What: volcano discharge.
- benefits:
fly ash:
- residues generated in combustion.
- benefits: improves workability. reduces drying shrinkage.
silica fume:
- 100x finer then portland cement. by product of producing silicone metal.
- benefits: strength. low-permeability.
blast furnaces:
- what: by quenching molten iron slag.
- benefts: improves workability, increases strength. reduces permeability.
concrete - admixture
other ingredients. added to concrete to alter its properties in various of ways.
- air entering: increases workability, reduce freeze-thaw damage
- water reducing: allows reduction in the amount of mixing water.
- accelerating: causes concrete to cure more rapidly.
- retarding: causes concrete to cure slower. to allow more time to work with.
Concrete - Building assembly - making and placing concrete
strength of cured concrete
- amount of cement in mix
- water-cement ratio (no greater then 45-60%)
test: slump test for workability
compressive strength: taken to test lab 48 hours later –> cured for certain time –> tests compressive strength. If uncertain –> test cores drilled –> if bad: cut out defective and replace.
concrete segregates if:
- vibrates
- moves horizontally
- dropped 3-5 feet
curing: reached after 28 days but still strengthens within the 6 months.
Concrete - Reinforcing - simple beam/continuous beam
concrete: resists compression forces.
horizontal beams: resists tension
vertical stirrups: resists diagonal tension near the ends of the beams = torosional twisting force
Concrete - Reinforced - concrete slab
One-way: rectangular and has one beam.
Two-ways: square/nearly square and has 2 beams
- stop steel for beam
- shrinkage temperature bars
- no vertical stirrups
- concrete thickness acts as beam
Prestressing
purpose: avoids concrete from cracking. 2 types.
Pre-tensioning:
- stretch steel
- cure/bond concrete to steel
- cut steel ends = concrete then moves into compression
post-tensioning
- concrete doesn’t cure/bond to steel
- add hydraulic jacks on ends. Steel beam is bent in opposite direction for higher efficiency.
Site cast concrete framing system - Slab on grade
purpose: for roads, airport runways, basements, sidewalks.
1. remove topsoil to expose subsoil beneath
2. 3/4” of crushed stone 4” deep for drainage
3. vapor retarder
4. welded wire reinforcement
5. concrete (residential = 3”) (industrial = 6-8”) (airports = 300mm)
6. everything is surrounded by temporary edge for brace.
selecting a site cast framing system (one-way or two-way)
- Is it square? 2-way
- finished ceiling? One-way or flat plate.
- How heavy are loads? Ordinary: two-way flat plate or one way joist system. Heavy: One-way
- How long are spans? 25-30’ = two-way. Longer = One-way
- Does the vertical stability h ave to be supported by concrete frame? One-way.
One-way Types: beam and girders, band slabs,, joist system and joist bands, welded joist system and joist bands.
Two-way: solid slab, drop panel and mushroom capital, flat plate, waffle.
Concrete - Sustainability
e
glass - ingredients
sand, soda ash, lime, alumina, potassium, oxide, elements for colouring.
glass - annealed
slow coolig
glass - tempered
heat-treated
purpose: safety glazing that has no frame ex: hockey rinks, basketball nets.
stress: higher residual stress then annealed
strength: x4 then annealed
breaks: squares
cuts/edged BEFORE heat-treatment
glass - laminated
ingredients: polyvinyl butryal (PVB) between 2 glass.
- strength: weaker then annealed
- breaks: into the layer so doesn’t spread.
- sound & UV: sound is better then solid glass. UV is reduced transmission.
glass - spandrel
A fritted glass on the interior where the floor intersects the glass. Contrasts with the surrounding glass.
- tempered or heat-strengthened
glass - fritted
purpose: to reduce the amount of light and heat from entering building. dot-matrix or ceramic-frit.
colours: black: attracts heat.
white: avoids heat.
glass - fire-rated
ingredients: double: gel between 2 tempered glass. or transparent intrimescent between 2 annealed glass.
times: temperered/laminate = 20min. Wired = 45 min. optical ceramic = 20min - 3h
purpose: for doors/windows to create a barrier from smoke entering.
Insulating Glass
- and low emissivitty coating
why: Glass is a poor thermal insulation. Improve with double/triple glazing but still doesn’t compete with wall.
Further improve:
- prevent moisture by sealing units with pumped air-dry at manufacture.
- use stainless steel or broken aluminum spacers.
- Use desiccant chemical (aargon/krypton) improves 12-18%.
- close with primary and secondary seal.
Performance rated with U-factor and it’s R-value.
Classic: double-glazing is 1” thick with 1/4” airspace and 1/2” glass.
Low-e: ultra thin, transparent, colourless metallic to prevent solar radiation at different wavelengths.
- hot climate: low-e located at 3 position.
- cold climates: low-e locate at 2 position.
Glass - Building assembly
Stick or Uniform.
glass sustainability
e
Masonry - hot climates & cold climates
hot climates:
- mortar dry’s faster
- keep shaded
- may have to be dampened
Cold climates:
- keep mortar dry
- protect from freezing temp before use
- warm mixture water
protect finsihed work from freezing 2-3 days
- protect wall from rain and snow
- no chemical acceleration or anti freeze mixture
Masonry - Flashing and Drainage
Create weep holes at locations where water/moisture build up occurs. to prevent mold from growing.
below copings, above roof, cornice, ledge, lintel, window sill, base of wall, below grade.
Masonry - expansion and contraction
expansion joints
control joints
abutment joints
= located near discontinuities and cracks.
Masonry - efflorescence
masonry should be tested to see if it was water-dolluble salts. a white substance will drip down finsihe work. = problem in appearanec.
