CONCRETE FORMS TO CONCRETE FOOTINGS

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Forming concrete walls with strip ease system rent this  system

-components: flat metal ties, steel bar walers, slotted plywood forms, hinged corners

-nail out side plate 19mm outside bldg line to concrete footing

-erect all corners plumb and nail to bottom plate

-attach top plate between corners

-attach plywood forms to bottom and top plate nail lightly

-insert flat metal ties into slots

-pull steel waler bars through slots

-build window and door bucks

-set up inside plywood forms threading onto ties

-brace and straighten outside wall

-set pour strip

- pour walls 

-strip walers by using hammer on steel bars

FAST FOOT

CONCRETE FORMING WITH DOUBLE WALERS

NOTE: plate must be 3/4" off of building line to allow for forming plywood

nail off all strong backs, corner locks with 3.25" duplex nails

the  4"x6" brace is used to hold form work against existing wall

preventing movement

the corner strong back is picked up by one waler and the blocking and wedge are picked up by the other set of  walers

batter boards

- are placed around excavations so that string lines can be put up on the grid lines

the battered boards should be erected using a 3,4,5 triangle from the bottom of the excavation example 4 feet of depth you would place batter board three feet from edge.

-try to keep the horizontals close so the strings touch when they cross

battered walls

have one side sloped the other side vertically plumb often used as retaining walls the sloped sides OFTEN NOT ALWAYS towards the retained ground..  steel is  stronger on battered side

beam band slabs

-ensure that scaffolding is at right elevation

-joists centred at right spacing

-ensure beams are built in centre of scaffolding

beam pockets

-bulkhead off beam pockets in top of walls make sure pour heights are at right elevation to ease stripping and eliminate chipping and skirting

beam sides

-plumb

- brace every three to four feet

-top 2x4 on edge

-bottom plate well nailed

-ensure packers for slab are not cantilevered

braces

-form adjusters(FA)s or turnbuckles

-braces must be angled less than 45°

-ideal brace is 2/3 of the way up wall

-ledgers are horizontal braces usually under slab soffits

-spreaders brace between sheathing to keep exact separation for wall thickness

-adjustable pipe braces for larger pours

-ribbon bracing of columns

bucks: windows, doors and other openings

- cut plywood 1 or 2 mm smaller than wall thickness

-plywood form chase the ends

- frame buck with two by four back cut ends slightly to ease stripping

- use nailing blocks on one side of concrete form to hang pre made buck at the proper elevation

- cross braces on bucks that are deep in the wall

-  place a wood keyway nailing strip on outside of bucks when using wooden frames in concrete wall

bulkheads

-ends of walls

the dry tie prevents the bulkhead from moving

-changes of elevations

-cut 2  mm smaller than actual wall size

capitals

top of columns used to support flat slabs

chamfer

- used to finish corners and for strike off on top of walls

circular

-use rebar as walers and 38 by 140 studs

climbing

slip climbing

cold joint

-where two pours meet

-on walls use a key way and rebar through the bulkhead

-below grade use a waterstop

construction joints as above

-  bulkheads key-wayed and holed for rebar

-footings keywayed or roughened

-rustification strips to blend pours

Corbels

- are thickening of walls at top

How to build:

Shoring method:

-regular forms ,

-one wall full height,

-corbel wall shorter, 

-then place a back wall behind shorter wall ends at same height

- double top plate for a beam on the top of corbel supporting  walls

- then cross joist between the walls with angle cut for corbel on one end of joist

-attach 2x4 plate to angle cut

-place studs for back of corbel up from joists, these studs are cut to proper angle for bottom of corbel, then soffit with plywood

Bracing method:

-expand wall at the corbel by using plywood gussets nailed to bottom stud wall and it’s offset stud wall

-cut top of gusset to the proper angle for corbel

- the bottom stud should be cut at the correct angle to also support soffit

-cover gussets with the plywood soffit

corners

How to:

-out side corners can be pre built to the thickness of the wall then plywood panels will match up inside wall  to outside wall

- waling of outside corners   first a corner lock against the wales than nail the walers together  then place kickers on the outside tongues

-this is called lacing the corner

dams

mass concrete lifts

domes

are concrete shelled roofs include: domes, hyperbolic paraboloids, barrel and folded plate roofs -beams around the domes are pre-stressed with post tensioning cables .. .shells can be as thin as 50 mm

door bucks for cast in place  metal door frames

-when placing metal frames fur out frame so that it is same as wall thickness

-plug any holes with rubber plugs

-ensure that metal frame is kicked securely on all sides

-place frame tightly against concrete form

-kickers on closing panel must fit snug against metal frame

elevator door bucks

- cut plywood for buck 1 or 2 mm smaller than wall thickness.. .then frame with 2x4

- the top plywood of the buck  forms a cap the 2x4 frame runs right across the top and is supported by the side frames of the buck

- cross braces on bucks width and height

embeds and templates

-be very careful precision is needed .. .use string lines , check diagonals and centre to centre distances mistakes here can cause lots of back charges! on templates mark out the centre lines of the template and work from the centre out to the holes

 embeds are placed in concrete to:

-protect edges

-weld plates

-for brick of facing ledgers

- to weld  beams or columns

 -anchor bolt for wall plates 12 bolt every 2400 inserted to a depth of at least 100

- as reglets for waterproofing (do not oil caulking will not adhere)

- often the use of a plywood template  is needed

-smooth dowels are often greased to be used

between slabs that might have lateral movement

-dowels can be placed wet, drilled and epoxied or screwed into cast in place inserts

engineer’s schedule

-form work construction

-placement of concrete

-order of stripping

-type of shoring

-location of shoring

-duration of curing

-curing conditions

-duration of reshoring

-reshoring placement

flat plate slabs

flat slab with columns

flat slabs

flat slabs with columns, dropped plates and capitals

floors

fly tables

- aluma stringers, joists, braces, legs,, backing rod, infill panels, rollers and cable jacks

-carefully locate pick points for balance

Moving:

-screw jack legs down until bottom chord rests on rollers (floor jacks maybe needed)

-keep skirting and filler panels attached to table for ease of installation

-tie off table before rolling forward to attach slings

-move forms outwards with cable jack

-remove pickup covers connect to crane run crane out connect power winch to second set of pick up points

-guide form out and lift

-reshore at engineered points

- mark leg points hold table with crane fold down legs and set on marks

-adjust legs with jacks

-place infills

footings

minimums: twice as wide as wall and the same thickness as the wall width

-use stepped footings on sloped ground 600 long 600 deep vertical connection at least 150, 400 for very deep slopes

- every side can run wild when using chased sides for the footings

-concrete foundations 150 to 300 thick

-crushed stone or coarse granular mat is used around perimeter and under basement slab for better drainage and radon mitigation

-new polystyrene forms are developed for basement forming and insulation and vapour proofing

-wood joists and beams set in concrete walls less than 150above grade must have 12 air space and sit on a moisture barrier or be treated with a decay preservative

-after stripping all tie holes must be filled and waterproofed

-anchour bolts for sill plates 12.7 spaced at 1853 NBC embedded 100

gangs

-braced securely

-tapered ties or coil rods example shows double waler wall

-giant gang bottoms anchored with bolts drilled into footing

gangs, walls

PLES

-place, length, elevation, size

PLESS

-plumb. level, even, square, straight

check list:

-braced special notice to meeting of walls “T”

-studs and wales are in place

-insert seams are tight

-no nails protrude through skin

-all ties and wedges secure

-corners laced and kicked

-bulkhead correctly placed and nailed

-embeds are placed accurately and secured

-bucks are placed braced and nailed

-leveling strip right elevation and secure

-stripped with out wastage of material

hoarding

are used  over streets to protect public

-2.5 meters high

-roof slopes towards site

- must have warning lights if on street

isolation joints

give and take materials must be compressionable

joints

-isolation joints .. give and take

-slab use give and take strips or saw cuts

-walls use chamfer

-rebar usually every second horizontal

-control joints grooved and less rebar ..  “T” strips forced into a groove top pulled off leaving plastic insert concrete is trowelled finished over top

-wall control joints combined thickness of wood inserts should be 1/5 of wall thickness, insert strips should be 20 beveled to 12 .. control joints are necessary in walls greater than 25 m, first at natural weaknesses doors, windows then 3 m from corners and then 6 m apart

-cold joints: should be cleaned, roughened, wetted,  a layer of bonding material or a layer 12 of grout before new concrete is poured on top

-construction joints below grade use water stop, keyways and bulkheads are designed to take rebar

joists for false work

 6.5 inch alumas or 4x6  douglas fir, they sit on stringers to support soffits on suspended falsework

-deflection of 19 plywood Forms:

24 inch centres support 100 lb. per square foot

20 inch centres support 200 lb.

16 inch centres support 400 lb.

12 inch centres support 800 lb.

8 inch centres support 1600 lb.

4 inch centres support 3200 lb.

Pressure of concrete at rate ft/hour vibrated

averages from 150 to 220 psf depending on temperature

ties, braces, double wales

Pressure of concrete at:

100lbs tie every 6 feet

200lbs tie every 5 feet

400lbs tie every 4 feet

800lbs tie every 3 feet

1200lbs tie every 2 feet

3600lbs tie every 1 foot

keyways

made from 2 by material should be beveled and oiled or greased with lithium

kickers

-used to lock corners on walls nailed to the outlooks of the walers (on the wall sides of the outlook)

ledgers

-ledges to hold joists or soffits

offsets

-a narrowing of the wall usually to carry a slab or masonry veneer finish

-easiest way is to fur out the form wall

pilaster

 a column placed in the wall

How to:

- ply wood sides are cut to fit between the wall and outside of pilaster

- stiffeners for sides run from wall waler to pilaster walers

build so they tighten with the pressure of concrete

reglets, reveals

- reglets are inserts in concrete to hold  flashing

-reveals are inserts attached to concrete Forms for decorative edges

-rustification strips used at top of walls to blend pours from one floor to next

Round  and curved walls use 10 m rebar as walers, 

cut plates to proper radius out of 3/4" plywood,

nail strong backs to plates to give wall desired shape, 

tight radius use hardboard as forming sheathing nail to stromg backs

RETAINING WALLS

Retaining wall thickness , footing size and reinforcement all increase with height of wall.

sauna tube

-round fibre tube for pouring columns

-must be kept dry

build 38 by 89 crib to hold on floor and use “FA” to brace the top

-lower pump hose down tube to pour

- sauna rebar reinforcment  called a zone, combines verts and ties

scaffold

-holds falsework for floor soffits

sheathing

-high density plywood for  smooth finish has an opaque resin finish

 -form ply usually three quarter inch and 7 ply (layers)

-oiled 200 uses?

slip forming

- inward tilt called battered is about .3% outward from bottom

-yokes hold Forms together with walers attached yokes are comparable to outer strong backs

-300  mm per hour by jack assemblies embedded in concrete base

-finishers scaffold below form attached to yoke walers

-lifting load depends on jack and jack rods

-jack rods must be sleeved for reuse

-slip form wales are 38 lumber

slip Forms are usually about 1200 deep

snap ties

- flat from sheet metal: strap ties,  and strip ease ties

-coils used with , coil cones, coil rod, plates and bolts

-standard cone ties 6000 lb. come in long end and short end use wedges or brackets are coned  to act as spacers

spandrels

- outer face of slab is the spandrel beam

stairs

- under side is soffit

stringers

7.5 inch alumas sit on top of scaffold heads for suspended slabs hold 6.5 joists

studs

- 2 by 4 strong backs against plywood

-rule of thumb for centers of 2 by 4 studs on 3/4 inch plywood with out deflection

-24 inch centres 100 lb.

-20 inch centres 200 lb.

-16 inch centres 400 lb.

-12 inch centre 800 lb.

-8 inch centre 1600 lb.

-4 inch centres 3200 lb.

T WALL HAVE IMMENSE PRESSURE SO INCREASE REINFORCEMENTS TO SAVE ON DEFLECTION

tilt ups

- wood Forms

-steel trowel slab

-slab must be beefed up for extra loading re crane

-release agents

-cure about 1 week before tilt

-strong back help to stiffen panel when tilting

-lots of rebar is required

-embeds or pick up  inserts..  wall and knee brace inserts..  strong back inserts.. .

- aligned after set up with adjustable braces

-inserts must be engineered to distribute load strain

-pilaster clamps secure concrete form work between tilt up panels

-to tilt up panel cranes are best positioned to either side

-tilt panel is lifted as close to vertical as possible to reduce strain on concrete

-set in place between steel dowels at bottom

-panel must be plumbed with all knee braces installed and bolted to floor before crane release

-minimum of 2 braces per panel

-permanent secured by welding to floor plates

 double walers..double end ties at 1',3',5',7' horizontally and vertically on an eight foot wall

-strong backs or studs are used behind form ply for strength,, concrete 150lbs/cubic foot

example 6' wall force on bottom of wall 6x150=900lbs

-rule of thumb re force of concrete and stud spacing to prevent deflection of plywood

-24 inches stud centres 100 lb.

20 inch stud centres 200 lb.

16 inch stud centres 400 lb.

12 inch stud centres 800 lb.

8 inch stud centres 1600 lb.

4 inch stud centres 3200 lb.