Concrete is made by mixing: ** Answ** (B) cement, sand, water, and gravel
Ready mix concrete is purchased by the cubic yard, which is how many cubic feet? ** Answ**
(B) 27
A bag of Portland cement weights how much? ** Answ** (B) 94 lb.
The thermal process known as hydration refers to: ** Answ** (C) the curing process
What is meant by 1:2:4 concrete mix? ** Answ** (C) 1 cement, 2 sand, 4 gravel
A slump cone is a metal cone used for: ** Answ** (A) determining the water mix in
concrete
When air entrainment is desired for freeze thaw conditions, it can be blended into the mix by:
** Answ** (B) adding a separate air entraining agent
Reinforced concrete is accomplished by adding: ** Answ** (A) reinforcing rod
(B) welded wire
Concrete is kept from freezing by: ** Answ** (D) maintaining the temperature above
freezing
The term "fine aggregate" refers to well-graded gravel up to: ** Answ** (A) 1/4 inch
In comparison to regular concrete, air entrained concrete: ** Answ** (A) has more
workability
(C) is more durable in freeze/thaw conditions
, Air entrainment is used for what? ** Answ** (B) making concrete more durable in
freeze/thaw conditions
What additive when added to mortar decreases strength but increases workability? ** Answ**
(C) lime
A number 3 rebar is what diameter? ** Answ** (C) 3/8 inch
What is cement paste? ** Answ** (B) Portland cement and water
What is the major component of Portland cement? ** Answ** (A) pulverized limestone
When water is added to Portland cement it causes the mass to harden. This reaction is called:
** Answ** (B) hydration
Accelerators speed up the curing process. Which of the following is an accelerator? ** Answ**
chloride
Under ideal conditions the best temperatures to pour concrete would be: ** Answ** 55 to 75
degrees F
What is used to prevent concrete from sticking to wood forms? ** Answ** oil
A footing and a wall are two parts of a: ** Answ** foundation
The recommended minimum strength of concrete used for footings is: ** Answ** (C) 2500
lb./sq. in.
The most commonly used additive to help concrete set rapidly and more cohesively is: **
Answ** calcium chloride