G-3 Flashcards
When can footings be cast in excavated forms?
when the sides of the excavation are stable enough not to collapse into the footing before or during concrete placement
What type of footing is typically used under a concrete wall?
Strip footing
Name four components of wall forming
sheating
studs
walers
ties
Explain how strap ties are secured to the studs
nailed to the studs on alternate sides
Explain how the forces of the fresh concrete reach the wall form tie
concrete preses against the sheating which presses against the studs or walers, which transfers to the wedges and then to the ties
What size of material is used for the walers and studs when using single or double waler form systems?
2x4
What controls the maximum spacing of the students in a double waler system?
amount of allowable sheathing deflection
What wall farming system doesn’t need to be stripped?
insulated concrete forms (ICF)
Describe a pilaster and state its purpose
A pilaster is a thickening in the wall resembling a column. It is used to support the extra load from a column above.
Describe a corbel and state its purpose
A corbel is a widening in a wall creating a ledge or thickened top. This may be for structural or for decorative purposes.
When would FRP be used to build column forms?
Architectural concrete
What is the most common column shape?
Round, rectangular
Why are there three size for the same nominal diameter of fibre tube?
Transportation purposes
When would steel column forms be used?
When there will be many re-uses
How can the concrete column’s finish be improved when using fibre forms?
Use a plastic liner
What type of materials are conical column capital forms made from?
metal or FRP
Which form requires no banding or column clamps
round fibre
How are colum forms held together?
Ties, clamp, banding
How are column forms usually adjusted to the exact required height?
shim the bottom
What is the advantage of having all side of square column form cut to the same size?
sides are interchangeable
What order should the carpenter use when planning the wall form layout?
Corners and T-panel locations, then steps, full panels, and infill
For what height of foundation wall does WorkSafeBC OHS Regulation require certification by a P.Eng?
4m (13 ft) and higher
Is a P.Eng required to certify gang form drawings?
Yes
What is the maximum height of a step in a footing?
600
What is architectural concrete?
Concrete surfaces that are to be left expose to view
What is a serious drawback to using fibre form tubes for columb forms?
They will only stand up to being wet for a limited time
If the design required to be certified by a P.Eng what must inspection be done by the P.Eng?
Immediately before placement of concrete or other intended loading
List the requirements for footings
Positioned accurately
Correctly dimensioned
Level
What is the maximum vertical step allowed for a step footing?
600m or 24”
Once simple outside footing forms are in place, how are the inside forms postioned?
using cleats as spacers and staked in place
What are the first few steps before placing wall forms?
Strip off the cleats, sweep the footings clean, mark the foundation wall location with chalk lines
How is the bottom plate fastened to the concrete footings?
Hand nailed if the concrete hasn’t cured, with powder-actuated fasteners if it has
Which wall forms normally get placed first?
Outside corners
Where is the bracing usually placed?
On the outside forms (usually to strongbacks)
Why is the construction of an outside corner of a concrete wall form so important?
Because there are concrete pressures from two directions
Why must high-quality forms be used for architectural concrete?
Because the concrete will be left exposed as the wall final finish
How many times can concrete forms be reused if properly looked after? What should be done to prolong the forms/ usable lifespan.
Hundreds of times. Do not be overzealous when nailing or stripping.
What are kickers used for when forming single and double waler walls?
To lock the outside corners
Explain how to install a wedge for a double waler
The wedge should be installed so that the snap-tie button is midway between the walers.
How are waler bars removed when stripping quick strip forms?
Hammer the ties parallel to their width to break them at their break back point
What is attached to rough door and window bucks to keep the finished door or window frames from moving after the frames are installed?
Reverse keys
Why is a buck designed to be slightly larger than the frame to be installed?
To allow for shimming of frame at time of installation
Why shouldn’t any of the sides, tops, or bottoms of bucks run the full length of the buck?
To accommodate ease of stripping
What is attached to a wall form to create a pocket for a beam?
A blockout
Describe how to set a bulkhead in a steel form
Braces to the ties outside of the bulkhead
How is a bulkhead made easier to strip?
Made of lumber instead of plywood, very important when dowels protrude through the bulkhead
How is the height of the finished concrete wall indicated if a level strip is not used?
Driving nails into formwork along a chalkline at the desired pour height
Name three uses for rustication strips
Decorative, use as a levelling strip to hide a construction joint, use to create a control joint
What type of tools should be used to pry forms loose when stripping?
wood wedges, wood bars
Why must rustication be removed very carefully?
so not to damage green concrete
Explain the stripping process for foundation forms.
Orderly and safely, remove cleats, 2x4s walers and ties, sheathing
Explain how to strip and lift gang form panels.
Use fall protection, partially strip, attach tagline and crane, tension crane, finish stripping, clear area
Explain how to strip and lift slab tables
Use fall protection, lower jack onto dollies, attach lines to core, roll out 1/4 way, attached first pair of slings, roll out and attach second pair of slings, detach lines to core, hoist out
