CIM 3330 Formwork

Formwork is the _______ into which concrete is placed before it hardens.
Click the card to flip 👆
1 / 39
Terms in this set (39)
Formwork is the _______ into which concrete is placed before it hardens.
mold
The purpose of using formwork is to ____________ and ___________ concrete until it has cured sufficiently to support itself.
shape, support
Formwork must be strong and stable to withstand the _______ and _________ of fluid concrete without _______________________.
weight, pressure, excessive deflection
During curing, the formwork helps retain water for __________
hydration
After curing, formwork must separate from concrete without damaging structure. (Use ____________________.)
A form release compound
Well constructed concrete forms should be substantial enough to retain their correct shape ________ __________
when filled
To resist high loadings, both moving and stationary. Freshly mixed concrete exerts great pressure since concrete weighs from __________ to ___________ per cubic foot.
130, 150lbs
Well constructed concrete forms should be To withstand the_____________ ___ __________ of concrete.
effects of vibration
Well constructed concrete forms should be tight to prevent the escape of the _____________-________ __________, because the loss of water will change the strength of the remaining mixture.
water-cement paste
To lend themselves to rapid construction, erection, stripping and moving. Constructed so they can be easily filled from a truck or wheelbarrow. Easily removed after the concrete has _____________.
hardened
___________ __________ are usually reuseable and made of wood, metal, or plastics. Wooden parts of forms in contact with the concrete is often high grade lumber or plastic overlayed plywood.Temporary Forms_____________ ________ are usually of corrugated metal, and remain in place once the concrete has hardened.Permanent Forms________ ___________ _____: works OK and is cheap, will not leave a stain on new concrete. a good source is fast food restaurants like Mac Donalds. will rot plywood eventually.Used vegetable oil_________ ________ ____l: Works well, can be very cheap if you live near a dump. It is really dirty to use and stains the concrete.Used motor oil_________ ____ __________: works OK... clean to use, a little expensive if the project is large.Grease and diesel_________ _______ __________: works well, fairly clean and no residue on concrete.(heat diesel until the candle wax melts, a really hot day will do it or bucket with glass over it on a hot day.) Cheaper than grease and improves the number of uses. Not so cheap.Parafin and dieselFormwork accounts for ___ to ___ of the construction cost for concrete framed buildings, hence its importance as a major component of the equipment array used on such construction projects.30, 70%Formwork is expensive, which is why it is most often designed to be __________. When possible, formwork is omitted, as in the case where footings or grade beams are poured directly on the earth.reusedSystems are chosen considering many factors, including The number of _________ ________ and the desired ______.repeat uses, finishSystems are also chosen considering these factors: ______________ ________ to ______ times The acceptability of _________ __________Versatility, Pour to strip , cold jointsGenerally speaking, the faster you can strip the less __________ ______ _______ __________wear on your formsThe faster you strip the greater the ____________ to the concrete as possible.damageCoarse finishes will result even from smooth forms when they are stripped under _____ hours.48Assembled in situ from standard elements new for each use and is disassembled after each useConventional formworkMostly factory-fabricated products and are used many times as one unit without being disassembled and assembled again for each useIndustrialized formworkWhat are the two vertical loads on horizontal forms?Live loads, dead loadsHorizontal pressure on the surface of the forms, are proportional to the ________ and _________ of the concrete in a liquid or semiliquid statedensity, depthHorizontal Systems typically come in two configurations: ______-________ forms ____________ (flying) formshand-set, tableFor Horizontal Systems, stripping times much ___________ than for vertical elementsLongerWall-and-slab forming systems come in two configurations: ______-________ forms ______-_______ formshalf-tunnel, full-tunnelICF are basically forms for poured concrete walls, that stay in place as a __________ ________ of the wall assembly.permanent partICF forms are made of __________ _______________, are either pre-formed interlocking blocks or separate panels connected with plastic ties.foam insulationFor ICFs The left-in-place forms not only provide a continuous ___________ and __________ __________, but also a backing for drywall on the inside, and stucco, lap siding, or brick on the outside.insulation, sound barrierForms should be coated with _________ _______ ____ or other release agents.used motor oilForms must be braced to prevent ____________.bulgingForm should not be removed until the concrete is strong enough to ________ __________ (time varies with weather, mix and admixtures).Stand aloneForms, although their function is temporary, are engineered structures. The forms must be constructed with an adequate factor of safety to prevent the possibility of _________ or ___________.failure, collapseThe mechanical handling of formwork on site, a characteristic of industrialized forming systems, is a _________ ___________.Critical operationAll parties involved in crane handling of the form should be aware of form's weight and the proper ____________ ________.weight, handling method