Irving Questions and Answers 100% Solved correctly
It is allowable to remove the temperature measuring devices from the freshly
mixed concrete to read the temperature if you cannot see the reading. (T or F) -
ANSWER -False
The maximum allowable time between obtaining the first and last portions of the
composite sample may not exceed 5 minutes. (T or F) - ANSWER -False
Start molding specimens for strength tests within 30 minutes after fabricating the
composite sample. (T or F) - ANSWER -False (15 mins)
The composite concrete sample must be protected from sun, wind, contamination
and rapid evaporation. (T or F) - ANSWER -False (Contamination and rapid
evaporation)
If the concrete contains aggregates larger than those that are appropriate for a size
of mold or equipment used, the sample should be wet-sieved before making the
test. (T or F) - ANSWER -False (wet screened)
The composite sample not be remixed before beginning any tests. (T or F) -
ANSWER -False
Sampling should normally be performed, as the concrete is discharged from the
mixer. (T or F) - ANSWER -True
ASTM Method C172 includes the sampling from stationary mixers, paving
mixers, truck mixers, agitators, and non-agitating equipment. (T or F) - ANSWER
-True
After sampling is completed, start the tests for slump and air content within: -
ANSWER -None of the above (5 mins)
, In any case, do not obtain samples until: - ANSWER -All the water and
admixtures have been added to the concrete
No samples shall be taken before ______ or after ______ of the batch has been
discharged. - ANSWER -
When strength tests are to be made, the minimum size of the composite sample
shall be: - ANSWER -1 cubic foot
Sample the concrete from the chute of a truck mixer by: - ANSWER -
Fresh concrete to be tested at the job site should be sampled from: - ANSWER
Two or more regularly spaced intervals during discharge of the middle portion of
the batch
The elapsed time between obtaining the first and final portions of the composite
sample, according to ASTM C172, shall not exceed: - ANSWER -None of the
above
The sides of the slump cone should be tapped with the mallet to consolidate the
concrete in the mold. (T or F) - ANSWER -False
For the slump test, when Rodding the second layer and the top layer, the tamping
rod should just penetrate into the underlying layer. (T or F) - ANSWER -True
According to ASTM C143, it is permissible to use a mold, which clamps to a
nonabsorbent base. (T or F) - ANSWER -True
When filling the final layer of the slump cone, never heap the concrete above the
top of the mold. (T or F) - ANSWER -False
The filling of the slump cone should be done in three layers of equal height. (T or
F) - ANSWER -False