ACI Concrete Field Testing Technician- Grade I Exam Questions with correct Answers The sensor of the temperature measuring device shall be submerged a minimum of _____ in. [_____mm] into the freshly mixed concrete. - Answer- 3 in. [75 mm]
The temperature measuring device shall have a capacity of measuring temperature of freshly mixed concrete to +- _____ degrees F [+- _____ C] throughout a range of _____. - Answer- 1 degree F [0.5 C], 30 degrees F to 120 F [0 C to 50 C]
The temperature measuring device shall be calibrated _____, or whenever there is a question of _____. - Answer- Annually, accuracy
The temperature of concrete may be measured in a wheelbarrow. True or False? - Answer- True
The temperature of concrete may be measured in a wall form. True of False - Answer- True
A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temperature. True of False? - Answer- False
What must be done to the sample container prior to sampling the concrete? - Answer- Dampen (with water)
What must be done to the concrete surrounding the temperature measuring device after
the device is submerged in the fresh concrete. - Answer- Gently press the concrete around the temperature measuring device at the surface of the concrete
How long must the temperature measuring device remain in the freshly mixed concrete?
- Answer- At least 2 minutes but not more than 5 minutes
After the temperature of the concrete is read, what is required? - Answer- Reporting of temperature
The temperature of concrete is reported to the nearest _____ degrees F [_____ C] - Answer- 1 degree F [0.5 C]
According to ASTM C1064, what is one reason to take the temperature of concrete? - Answer- Verify conformance to a specified requirement for temperature of concrete A maximum temperature of freshly mixed concrete is specified in ASTM C1064. True of False? - Answer- False
The sample of concrete used for temperature determination must be rodded 25 times. True or False? - Answer- False
Sampling by this method is required when tests are to be made to determine _____ with
specification requirements. - Answer- Compliance
This method covers sampling from four types of mixtures which are _____, _____, _____, and _____. - Answer- Stationary mixers, paving mixers, revolving drum mixers, and open top mixers
The maximum allowable time between obtaining the first and final portions of a composite sample is _____ minutes. - Answer- 15
Portions of a composite sample shall be thoroughly remixed bfore beginning tests on the sample. True of False? - Answer- True
The maximum elapsed time allowed between obtaining the final portion of the composite sample and beginning the tests for slump, temperature, and air content is _____ minutes. - Answer- 5
The molding of strength test specimens shall begin within _____ minutes after fabricating the composite sample. - Answer- 15
The concrete sample must be protected from contamination and _____. - Answer- Rapid evaporation
The minimum size sample for making strength test specimens is _____. - Answer- 28 L (1ft^3)
When sampling from a stationary mixer, the batch must be sampled at _____ or more regularly spaced intervals during discharge of the middle portion of the batch - Answer- 2
The composite sample for a paving mixer must represent a minimum of _____ different portions of the batch of concrete taken from the pile after discharge. - Answer- 5
When sampling from a revolving drum truck mixer, concrete must be sampled at a minimum of _____ regularly spaced intervals during discharge of the middle portion of this batch. - Answer- 2
Concrete samples from a truck mixer must be obtained before any water or admixtures are added to the mixer at the job site. True or False? - Answer- False
The temperature measuring device shall have a capacity of measuring temperature of freshly mixed concrete to +- _____ degrees F [+- _____ C] throughout a range of _____. - Answer- 1 degree F [0.5 C], 30 degrees F to 120 F [0 C to 50 C]
The temperature measuring device shall be calibrated _____, or whenever there is a question of _____. - Answer- Annually, accuracy
The temperature of concrete may be measured in a wheelbarrow. True or False? - Answer- True
The temperature of concrete may be measured in a wall form. True of False - Answer- True
A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temperature. True of False? - Answer- False
What must be done to the sample container prior to sampling the concrete? - Answer- Dampen (with water)
What must be done to the concrete surrounding the temperature measuring device after
the device is submerged in the fresh concrete. - Answer- Gently press the concrete around the temperature measuring device at the surface of the concrete
How long must the temperature measuring device remain in the freshly mixed concrete?
- Answer- At least 2 minutes but not more than 5 minutes
After the temperature of the concrete is read, what is required? - Answer- Reporting of temperature
The temperature of concrete is reported to the nearest _____ degrees F [_____ C] - Answer- 1 degree F [0.5 C]
According to ASTM C1064, what is one reason to take the temperature of concrete? - Answer- Verify conformance to a specified requirement for temperature of concrete A maximum temperature of freshly mixed concrete is specified in ASTM C1064. True of False? - Answer- False
The sample of concrete used for temperature determination must be rodded 25 times. True or False? - Answer- False
Sampling by this method is required when tests are to be made to determine _____ with
specification requirements. - Answer- Compliance
This method covers sampling from four types of mixtures which are _____, _____, _____, and _____. - Answer- Stationary mixers, paving mixers, revolving drum mixers, and open top mixers
The maximum allowable time between obtaining the first and final portions of a composite sample is _____ minutes. - Answer- 15
Portions of a composite sample shall be thoroughly remixed bfore beginning tests on the sample. True of False? - Answer- True
The maximum elapsed time allowed between obtaining the final portion of the composite sample and beginning the tests for slump, temperature, and air content is _____ minutes. - Answer- 5
The molding of strength test specimens shall begin within _____ minutes after fabricating the composite sample. - Answer- 15
The concrete sample must be protected from contamination and _____. - Answer- Rapid evaporation
The minimum size sample for making strength test specimens is _____. - Answer- 28 L (1ft^3)
When sampling from a stationary mixer, the batch must be sampled at _____ or more regularly spaced intervals during discharge of the middle portion of the batch - Answer- 2
The composite sample for a paving mixer must represent a minimum of _____ different portions of the batch of concrete taken from the pile after discharge. - Answer- 5
When sampling from a revolving drum truck mixer, concrete must be sampled at a minimum of _____ regularly spaced intervals during discharge of the middle portion of this batch. - Answer- 2
Concrete samples from a truck mixer must be obtained before any water or admixtures are added to the mixer at the job site. True or False? - Answer- False
