Properties of Concrete- Review Questions
c. granulated blast-furnace slag
A commonly used ingredient in blended cements is... a. ground sandstone b. fine gravel c. granulated blast-furnace slag d. diatomaceous earth
a. workability
A slump test is used to determine concrete's... a. workability b. compressive strength c. water-cement ration d. curing time
a. cold weather
Accelerating agents are admixtures that are commonly added to concrete in... a. cold weather b. very humid conditions c. hot weather d. very dry conditions
b. 24 hours
After specimen containers for compression testing have been filled with concrete, they should not be moved for... a. 8 hours b. 24 hours c. 3 days d. 28 days
d. seal in moisture
Curing compounds are sprayed on freshly placed concrete to... a. increase evaporation b. protect the surface c. improve appearance d. seal in moisture
d. retard the setting time
Gypsum is added to portalnd cement to... a. prevent clumping b. increase the setting time c. improve workability d. retard the setting time
c. green
Hardened concrete that has not yet reached full structural strength is referred to as... a. plastic b. immature c. green d. uncured
b. limestone
In portland cement manufacturing, the source of calcium is finely ground... a. clay b. limestone c. sandstone d. basalt
a. 15 minutes
In the first stage of hydration, temperature, increases rapidly for about... a. 15 minutes b. 30 minutes c. one hour d. three hours
b. weight
Prescriptive specifications for concrete are usually stated by... a. water percentage b. weight c. aggregate type d. volume
d. several years
Properly mixed and placed concrete continues to gain strength for... a. three month b. six months c. one year d. several years
b. within three to seven seconds
Removal of the slump cone from the sample should be done... a. as quickly as possible b. within three to seven seconds c. after obtaining approval d. slowly, over 15 to 20 seconds
d. aggregate
The component that constitutes 60 to 80 percent of concrete volume is... a. water b. pozzolans c. portland cement d. aggregate
b. II
The most commonly specified type of portland cement is Type... a. I b. II c. III d. IV
b. four
The number of basic materials in concrete is... a. three b. four c. five d. six
a. piece of rebar
To prevent introducing air into the concrete during slump testing, avoid rodding with a... a. piece of rebar b. smooth rod c. mechanical vibrator d. wooden dowel
c. durable
Use of too much fine aggregate in the concrete mix may make it less... a. attractive b. resistant to corrosion c. durable d. workable
a. 1 cubic yard
What volume of concrete will be needed for a pad 6' x 9' x 6"? a. 1 cubic yard b. 2 cubic yards c. 4 cubic yards d. 27 cubic yards
c. 1 1/2 inch
When preparing slump-test samples, sift out any aggregate larger than... a. 3/4 inch b. 1 inch c. 1 1/2 inch d. 2 inches
b. Three
When sampling concrete for compression testing, the molds are filled with how many equal layers of concrete? a. Two b. Three c. Four d. Six
