Contractors Guide To Quality Construction Flashcards
The 4 things control tests are for measuring:
Slump
Air content
Compressive strength
Yield
Control test results should conform to _____ international standards.
ASTM
Slump test is used to measure the ________________ of the concrete.
Consistency
__________ gives an indication of the workability, also called flowability or plasticity, of the concrete.
Slump
_____-_____________ improves the concretes resistance to damage from freezing and thawing cycles.
Air-entrainment
Without the proper ____ __________, normal concrete that is exposed to cycles of freezing and thawing will scale and spall, resulting in a failure of the concrete.
Air content
_______________ ______________ measures estimated strength at a given time to make sure it meets a job’s specified strength.
Compressive strength
Compressive strength is measured testing concrete cylinders either 6” dia. x 12” height or 4” dia. X 8” height tested at 28 days. At 7 day strength should be at ___-____% of the 28 day strength.
65-70%
_____ _____ replaces part of the portland cement content & visually reduces the air content in air-entrained concrete.
Fly ash
The stronger and less porous the cement paste, the stronger and more durable the concrete. Any _________ not needed for workability simply dilutes the cement paste, weakening it.
Water
Concrete is typically batched by __________.
Weight
The ____” sieve is the dividing point between course and fine aggregates.
3/8
The largest allowable aggregate will be the most economical, although a maximum of ____” or less is recommended for high-strength concrete.
3/4
____________________ when properly used can increase early strength, ultimate strength, accelerate or retard setting time, increase workability, improve uniformity, reduce permeability and improve durability.
Admixtures
__________-______________ admixtures enhance the workability of the concrete, making it possible to reduce the water by 5% or more.
Water-reducing
