G4 Flashcards
What kind of surface should slab on grade be placed
Well compacted
What factors affect the durability of slabs on grade
Compressive strength
Admixtures
Treatment
What factors affect the strength of slabs on grade
Compressive strength and proper curing
What should be done to walls or columns that pass through or beside slabs on grade
Barrier between slab and footing (caulking or preformed asphalt impregnated material
Why is it important to compact sub grade
Provides firm, even bearing
Why are screeds and forms liked before concrete placement
Easier to clean
What’s the difference between a flat plate slab and a flat slab
Flat plate - stays the same thickness and has no distinguishing features when striped.
Flat slab - column panels have either column capitals or a drop panel or both to support the slab
What advantage do column capitals have
More support for the slab
What direction does load-carrying steel span
Beam to beam
Dome panels are used in which type of slab
Two way ribbed slab
What is a spandrel beam
Perimeter beam
What sequence does form stripping usually take place
Beam sides, ties, slab shoring and first full size panels
First step in setting a beam form
Basic beam support, T-shore or double post.
What must be done to forms for deep girders
Studs added to the sides
Why does a spandrel beam require a wider shore head than other beams or girders
Because there is no wall support
Where do beam sides usually sit
Directly on the shore head
How are wooden t-Shores set
1” to 1 1/2” lower so wedging them up level and elevating can be done .
How are forks for drop panels supported
Rests on joists and stringers and finally on a shore head
What is the slenderness ratio
1:50
Describe a slab table
Aluminum truss shoring, stringers and or joist and screw jacks for levelling and a plywood deck
What are flying forms
Pre fabricated form work lifted in place with a crane
How are Aluma beans attached to the false Work
Wooden 2x2 or composite material in the top and a groove in the bottom that will accept the head of the bolt to fasten to the scaffold type shoring.
What are void forms used for
Used to reduce the overall em weight of the slab
What type of slab for work uses dome form pans
Waffle slab
How is a ribbed slab formed
With square end pans and tapered pans
What is OWSJ
Open web steel joist
When would FRP be used
When doing decorative work - waffle ceilings
Why would a waffle slab be used
Efficient material wise and good reduction in weight
What two basic slabs require the use of pans and domes in form work
Ribbed slab (one way) and the waffle slab (two way)
What must support concrete joists
A beam
Most common material for pans used to form ribbed slabs
Steel
What is a roller
Used to allow the slab to be rolled out of the building
What are floor jacks
Used to lower slab onto the rollers
Cable jacks
Used to move the slab horizontally out of and into the building.
(Basically come along that has been adapted to be used for moving slab tables)
Stripping safety
As each section is competed, the materials should be cleaned, oiled and carefully piled in a dry location
Types of grade compactors
Plate compactor and roller compactor
What is megapascals (MPA)
Compressive strength of the concrete
What are clean outs
Slot or opening in bottom of form where you can clean out
Materials for one way slab and joist systems
Long and tapered pans
What kind of steel is used for slab on grade
Mesh
