aci exam practice
10 to 15 times - Answer-the sides of the slump mold should be lightly tapped --- to
consolidate the concrete in the mold.
15 minutes - Answer-Start molding strength test specimens within ____ after
fabricating the composite sample.
28L (1ft3) - Answer-The minimum size for samples to be used for strength tests is.
3 inches - Answer-When determining the temperature of fresh concrete, what is the
minimum amount of concrete cover in all directions around the sensor of the
temperature measuring device?
4.8% - Answer-If the aggregate correction factor for a given source of fine and
coarse aggregate is found to be 0.2% in a pressure air meter, and an air content
value of 5.0% is read on the gage of the same air meter containing concrete with the
same aggregate, what is the correct air content?
5 minutes - Answer-Tests for the slump and air content must be started within ____
after obtaining the final portion of the composite sample.
6% = [(168-158)/168]×100 - Answer-According to test method C138, what is the air
content (in percent) of the following concrete batch.
The theoretical density computed on air free basis is 168 lb/ft3
The density is 158 lb/ft3
60-80*F - Answer-For normal strength concretes, what temperature range must be
maintained for test cylinders during initial curing?
adjust the rate of revolution of the drum - Answer-regulate the rate at which concrete
is discharged from a revolving drum truck mixer by
air content test - Answer-It is not acceptable to fabricate a test specimen from the
same concrete used for the
Determination that at least 8 hours have elapsed since final set. - Answer-
Preparation of the specimens for transport includes.
discarded - Answer-after wet sieving a portion of concrete sample, any aggregate
retained on the sieve shall be
