Transporting And Placement Of Concrete Flashcards
What happens if concrete is over-vibrated
Segregation of course aggregates
What is max size of Aggs when pumping concrete
1/3 size of hoes
When should forms be marked with pour height
After one side has been erected
What material is used for expansion joints
Asphalt impregnated fibreboard
What is used in the wet screed method
Concrete
Who establishes legal location of buildings
Legal surveyor
What truck is loaded with individual ingredients and mixes them together while on the way to site?
A ready mix truck
Pg. 13
What is a cold joint?
A cold joint occurs when fresh concrete is placed against previously placed concrete that has already begun to set.
Concrete should not be allowed to fall more then 1.5m? (True or false)
True, if concrete is allowed to free fall more then 1.5m it can cause the aggregate to separate from the paste.
Pg. 19
Once the hydration process has begun, how much time do you have to place the concrete?
2 hours.
Pg. 14
What factors influence hydro static pressure in fluid concrete?
•slump
•height of pour
•rate of pour
•ambient temperature
Pg. 22
How much shrinkage is expected is expected within the first three months?
75% of total expected shrinkage
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A truck that carries all ingredients to site and mixes them together on site is called a?
Mobile batch truck.
Pg. 14
When is a Mobile batch truck needed over a regular truck?
When the location of pour is outside of the 2 hour placement window.
Pg. 14
What’s the purpose of form watching?
To inspect and watch concrete forms for potential failure.
Pg. 25