PCI Quality Technician Level 1 - Chapter
4 Study Questions and Correct Answers,
100% Correct.
What ratio is used as a primary control for concrete design?
The water-cementious ratio
An increase in the amount of water used in a mixture could mean what?
-An increase in the slump
-A decrease in the strength
-Maintaining slump as the temperature rises
If the sand moisture increases from 4% to 8% and the same batch quantities are used with the changed
moisture, what will result for the mixture?
The amount of sand will decrease and the water will increase
An aggregate that is saturated surface dry is what?
An aggregate with no free moisture
A sand sample is taken for a morning reading. The wet weight is 800g. The dry weight is 762 g.
Absorption is 1.2%. What is the SSD weigth of this sample?
771 g - math in back of book
Wet weight is 800 g, dry weight is 795 g, absorption is 1.2%. How much free moisture will be available
from the sand when batched today?
None, the absorption of the sand has not been met. See back of book for math
Accelerated curing of concrete by adding heat generally results in what potential results?
A. Increased air in final product
B. increased early strength and slightly increased 28-day strength
C. Increased early strength and slightly decreased 28-day strength
D. Decreased strengths at early age
C. Increased early strength and slightly decreased 28-day strength
What is the typical, maximum allowable sustained curing temperature for accelerated concrete curing?
150 F
What procedures can be used to prevent plastic shrinkage
4 Study Questions and Correct Answers,
100% Correct.
What ratio is used as a primary control for concrete design?
The water-cementious ratio
An increase in the amount of water used in a mixture could mean what?
-An increase in the slump
-A decrease in the strength
-Maintaining slump as the temperature rises
If the sand moisture increases from 4% to 8% and the same batch quantities are used with the changed
moisture, what will result for the mixture?
The amount of sand will decrease and the water will increase
An aggregate that is saturated surface dry is what?
An aggregate with no free moisture
A sand sample is taken for a morning reading. The wet weight is 800g. The dry weight is 762 g.
Absorption is 1.2%. What is the SSD weigth of this sample?
771 g - math in back of book
Wet weight is 800 g, dry weight is 795 g, absorption is 1.2%. How much free moisture will be available
from the sand when batched today?
None, the absorption of the sand has not been met. See back of book for math
Accelerated curing of concrete by adding heat generally results in what potential results?
A. Increased air in final product
B. increased early strength and slightly increased 28-day strength
C. Increased early strength and slightly decreased 28-day strength
D. Decreased strengths at early age
C. Increased early strength and slightly decreased 28-day strength
What is the typical, maximum allowable sustained curing temperature for accelerated concrete curing?
150 F
What procedures can be used to prevent plastic shrinkage
