Concrete Mix Design Flashcards
What type of concrete is put in place using a pneumatic gun
Shotcrete
Where would light weight concrete be used
Masonry concrete and floors in high rise buildings
What is soil cement commonly used as
Base for asphalt pavements
Tensile strength is approximately what percentage of compressive strength
10%
What are mud slabs commonly used for
Work area, Not a structural part of building. (Used as a clean level surface for whatever the fuck u want)
Where would heavyweight concrete be used
Shield against X-rays, gamma rays and neutron radiation
When can forms be removed if rapid setting concrete is used
4 hours
What’s the cylinder test
Measures compressive strength
What’s the silt test
Determines presence of very fine clay particles
When mixing concrete what part does each number represent 1:2:4
1 part cement
2 parts sand
4 parts course aggregate
Colorimetric test
Presence of organic material
Calcium chloride is known as a
Set accelerator
What is a important quality of effective grout
Does not shrink
Difference between mortars and grouts
Mortars are bonders, grouts are fillers
What percentage of air should air-entrained concrete contain to be protected from damage by freezing?
5%-8%
Pg. 38
In what type of concrete do testing procedures measure flow ability rather then slump
Self consolidating concrete
What is a Superplasticizer used for in a concrete mix?
It is used to make a stiff mix flow freely for a short period of time.
Pg. 38
Which method of mixing concrete is only for small amounts mixed onsite
Mixing by volume
What is the main factor in attaining quality hardened concrete
Water/cement ratio
What is an accelerator used for in a concrete mix?
It is used to speed up the setting time and ensures early strength development
Example: calcium chloride
Pg. 38
Which of the following will minimize shrinkage in concrete
Proper gradation of aggs
Which of the following is considered a concrete additive
Air entrainment
What’s are retarders/set inhibitors used for in a concrete mix?
They are used to slow down the setting of the concrete. On hot days or when there are complicated finishes, retards are used.
Pg. 39
For standard concrete mix, what is the percentage amount of water used for hydration? 
25%-30%
