Concrete & Inspection Flashcards
Concrete is sometimes used a coating.
True or false?
True
Concrete does not require a coating.
True or false?
False, it may require protective coding
Concrete is formed with what?
Cement, aggregate and water
What are the characteristics of concrete?
Extremely durable
Inorganic
Hard
Has good compressive strength
Improves with age (hardens overtime)
Concrete has how many chemical reactions?
28
How is concrete cured?
Cures by hydration
Concrete pH may be as high as 13. True or false?
True
Concrete cannot passivate steel. True or false.
False concrete may passivate steel
What are some of the different concrete surfaces?
Poured
Concrete block
Special concrete surfaces, such as shotcrete, asbestos, glass fiber products
What is poured (wet cast) concrete?
Wet cast concrete is poured with the high water content to allow concrete to flow into form
What is poured concrete affected by?
Ambient conditions
Vibrations
Finishing operations
What are the finishing operations performed on poured concrete?
Troweling
Wood floating
Brooming
What are some issues found with poured concrete surfaces?
Pinholes
Rock and air pockets
Tie holes from tie wires
Offsets at junctions
What is guniting?
The process of spraying or slinging shotcrete onto a surface at thicknesses up to 10 inches inches
Preparation of concrete for coating includes what?
Pre-cleaning
Surface preparation
Surfaces/filling voids (most difficult)
Pre-cleaning of concrete includes the use of what?
Steam cleaning
Chemical cleaning
Detergents