G4 Flashcards
on which kind of surface should slab on grade be placed
sub grade or existing soil should be of suitable bearing or compacted fill
What factors affect the durability of slab on grade
protection from weather, water/ cement ratio or finishing
what factors affect the strength of slab on grade?
base material concrete mix, curing
What should be done to walls or columns that pass through or beside slab on grade?
provide isolation joints
why is it important t to compact the sub grade
give firm even bearing
why are screeds and forms oiled before oiled before before concrete placement?
easy cleaning
how long should slab forms remain in place in place after concrete placement ?
As long as possible
What is the difference between a flat plate slab and a flat slab
flat plate has a plain soffit, flat slab will have a drop panel or column capital
What advantage do column capitals give
increased shear strength and reduces strength span of load
What direction does load carrying steel span?
perpendicular to beams
dome pans are used in which type of slab
two way (waffle slabs)
what’s a spandrel beam
It’s located at perimeter of slab
how does a two way joist system differ from a single joist system
two way runs in two directions, one way runs in one
in what sequence does does stripping usually take place
beams sides then soffit
What is the first step in setting a beam form
place the beam bottoms on the shore system
why does a spandrel beam require a wider shore head than other beams beams or girders or the same width?
to provide space for walking
where do beam sided usually sit
on the shore head
how are wooden t-shores set to elevation
wedges
how are forms for drop panels supported
shores stringers and joists
What is the slenderness ratio
1:50 typical ratio of minimum ratio thickness of post to unsupported height
describe three ways shores are made adjustable
screw jack, wood wedges, Ellis clamp
why are re shores not fitted tightly to the concrete that they are supporting
so they won’t place undue pressures on the concrete while reshoring
describe a slab table
truss shoring, stringer joists, plywood deck, screw jack
What are flying forms?
fly tables or gang forms
