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ACI Concrete Strength Testing
Technician Questions and Verified
Answers. 2026-2027 Edition Rated A
_______ the pot and recharge with fresh materials at intervals to ensure
that the oldest material in the pot has not been used more than _______
times. - ANSempty, five
C39/M: Cylinder Testing
After all surfaces are wiped down, what is next? - ANSPlace the specimen
on the lower bearing block, and align under the center of thrust of the upper
bearing block.
C39/M: Cylinder Testing
After the lower bearing block is positioned, what is the next step? -
ANSWipe clean the surfaces of the platens, spacer disks, and bearing
surfaces of the specimen.
C39/M: Cylinder Testing
From when is the age of a specimen measured? What are the tolerances
for specimens of 1, 3, 7, 28, and 98 days of age? - ANSThe time of casting,
unless otherwise specified.
1
, 2
- 1 days: +/- 0.5 hours
- 3 days: +/- 2 hours
- 7 days: +/- 6 hours
- 28 days: +/- 20 hours
- 90 days: +/- 48 hours
C39/M: Cylinder Testing
The initial load has been applied in a test with unbonded caps. What is to
be done next? - ANSCheck the alignment of the specimen at two locations
90° apart, making sure alignment is with respect to the direction of load
application is within:
- 0.5°
- 1/8in per 12in (3mm per 300mm)
- 1/12in per 8in (2mm per 200mm)
If off, reload and check again.
C39/M: Cylinder Testing
The machine has been zeroed, the initial load has been applied, and any
necessary alignment checks have been made. How should they load be
applied? - ANSContinuously and without shock.
35 +/- 7 psi/second (0.25 +/- 0.05 MPa/sec)
2
, 3
For the first half of anticipated loading, machine may be advanced at a
higher rate. This is not mandatory.
The specified loading rate shall be maintained for at least the second half
of the loading phase.
Once yielding had begun, indicated by a drop in the loading rate, no further
adjustments are allowed.
C39/M: Cylinder Testing
The machine has been zeroed. If using unbound caps, what is the next
step? - ANSApply an initial load of less than 10% of the anticipated load
and pause the machine.
C39/M: Cylinder Testing
The specimen has been placed in the machine. What is the next step? -
ANSZero the machine.
C39/M: Cylinder Testing
What is the first step of the procedure? - ANSPlace the lower bearing block
on the machine or platen with the hardened face up.
The lower bearing block may be the platen in the machine.
3
, 4
C617/M: Gypsum Cement
After lowering the specimen into the paste, what is the next step? -
ANSAllow the gypsum paste to harden. This may take 20 minutes or more.
C617/M: Gypsum Cement
After mixing paste, what is the next step? - ANSUse any capping surface:
glass (1/4in, 6mm), metal (0.45in, 11mm), or stone/diabase (3in, 75mm).
Lightly oil capping surface.
C617/M: Gypsum Cement
What is step 1? - ANSMix gypsum cement paste to desired w/c ratio. DO
NOT EXCEED W/C ESTABLISHED FROM CUBE STRENGTH TESTS.
C617/M: Gypsum Cement
What is the next step after the gypsum paste hardens? - ANSRepeat the
procedure for the other end of the specimen.
C617/M: Gypsum Cement
What is to be done after the paste is poured onto the capping plate? -
ANSCarefully lower the specimen into the gypsum paste. Use guide bars or
a bulls-eye level to ensure perpendicularity to within:
4
ACI Concrete Strength Testing
Technician Questions and Verified
Answers. 2026-2027 Edition Rated A
_______ the pot and recharge with fresh materials at intervals to ensure
that the oldest material in the pot has not been used more than _______
times. - ANSempty, five
C39/M: Cylinder Testing
After all surfaces are wiped down, what is next? - ANSPlace the specimen
on the lower bearing block, and align under the center of thrust of the upper
bearing block.
C39/M: Cylinder Testing
After the lower bearing block is positioned, what is the next step? -
ANSWipe clean the surfaces of the platens, spacer disks, and bearing
surfaces of the specimen.
C39/M: Cylinder Testing
From when is the age of a specimen measured? What are the tolerances
for specimens of 1, 3, 7, 28, and 98 days of age? - ANSThe time of casting,
unless otherwise specified.
1
, 2
- 1 days: +/- 0.5 hours
- 3 days: +/- 2 hours
- 7 days: +/- 6 hours
- 28 days: +/- 20 hours
- 90 days: +/- 48 hours
C39/M: Cylinder Testing
The initial load has been applied in a test with unbonded caps. What is to
be done next? - ANSCheck the alignment of the specimen at two locations
90° apart, making sure alignment is with respect to the direction of load
application is within:
- 0.5°
- 1/8in per 12in (3mm per 300mm)
- 1/12in per 8in (2mm per 200mm)
If off, reload and check again.
C39/M: Cylinder Testing
The machine has been zeroed, the initial load has been applied, and any
necessary alignment checks have been made. How should they load be
applied? - ANSContinuously and without shock.
35 +/- 7 psi/second (0.25 +/- 0.05 MPa/sec)
2
, 3
For the first half of anticipated loading, machine may be advanced at a
higher rate. This is not mandatory.
The specified loading rate shall be maintained for at least the second half
of the loading phase.
Once yielding had begun, indicated by a drop in the loading rate, no further
adjustments are allowed.
C39/M: Cylinder Testing
The machine has been zeroed. If using unbound caps, what is the next
step? - ANSApply an initial load of less than 10% of the anticipated load
and pause the machine.
C39/M: Cylinder Testing
The specimen has been placed in the machine. What is the next step? -
ANSZero the machine.
C39/M: Cylinder Testing
What is the first step of the procedure? - ANSPlace the lower bearing block
on the machine or platen with the hardened face up.
The lower bearing block may be the platen in the machine.
3
, 4
C617/M: Gypsum Cement
After lowering the specimen into the paste, what is the next step? -
ANSAllow the gypsum paste to harden. This may take 20 minutes or more.
C617/M: Gypsum Cement
After mixing paste, what is the next step? - ANSUse any capping surface:
glass (1/4in, 6mm), metal (0.45in, 11mm), or stone/diabase (3in, 75mm).
Lightly oil capping surface.
C617/M: Gypsum Cement
What is step 1? - ANSMix gypsum cement paste to desired w/c ratio. DO
NOT EXCEED W/C ESTABLISHED FROM CUBE STRENGTH TESTS.
C617/M: Gypsum Cement
What is the next step after the gypsum paste hardens? - ANSRepeat the
procedure for the other end of the specimen.
C617/M: Gypsum Cement
What is to be done after the paste is poured onto the capping plate? -
ANSCarefully lower the specimen into the gypsum paste. Use guide bars or
a bulls-eye level to ensure perpendicularity to within:
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