G-7 place and finish concrete Flashcards
at what stages of finishing is an edger used and why
after bull floating , push large aggr away from surface and form and rounds over
why is a divider tool not used to make control joints
not deep enough
what is the purpose of hand floating or bull floating
push aggregate down
when is the placing of concrete completed
after floating
why should the bleed water be allowed to evaporate
ruin water cement ratio if not causes dusting or crazing
explain how a broom finish is created
floated ,broomed horizontally edged , edged and troweled
when are screeds removed from the concrete
after striking off
what is the purpose of a screed
guide for striking off
how is the top of concrete wall finished
cleats removed and floated
what is the purpose of kneeboards
disperse weight
what tool is used to transfer flexible patterns
tamper
what are 5 precautions when finishing concrete with a power trowel
concrete is flat/level
can bear foot pressure
cover area uniformly
bleed water evaporated
allow concrete to harden between passes
how is the movement of a power trowel controlled
push down = right
push up= left
what is a burnished surface
mirror like finish
created by steep angled trowels
what are 2 different types of blades for a power trowels
float and trowel
what are the environmental concerns associated with concrete treatments
streams and ground water
describe how sealers and hardens also act as curing compounds
prevents moisture loss
how is a exposed aggregate wall surface created
chemicals on forms
then washed off
what is the difference between damp proofing and water proofing
moisture resistant
resist hydrostatic pressure