ACI Grade I Field Testing Certification Practice Test - Q & A

ACI Grade I Field Testing Certification Practice Test - Q & A For concrete with aggregates less than 3 inches, the thermometer must remain in the fresh concrete sample a minimum of 5 minutes or until the temperature reading stabilizes. (T or F) False (2-5 minutes) The temperature measuring device must be accurate to within 0.1 degree. (T or F) False The temperature measuring device shall have a capacity of measuring temperature of freshly mixed concrete throughout a range of _____ to _____ degree F ( ______ to ______ degree C) 30 to 120 degree F (0 to 50 degree C) A composite sample is not needed if only the temperature test is being run. (T or F) True The temperature of fresh concrete in a placement must be measured by inserting a thermometer into the top six inches of concrete. (T or F) False (3 in.) The temperature of the concrete is recorded to the nearest ______ degree F (______ degree C) 1 degree F (0.5 degree C) ASTM C1064 states the container used to measure temperature of concrete must be large enough to provide at least 5 inches of concrete around the sensor. (T or F) False (The container shall be large enough to provide at least 75mm (3 in) of concrete in all directions around the sensor of the temperature measuring device) Calibrate the temperature measuring device at least __________, or whenever there is a question of accuracy. Annually After the thermometer is placed in the concrete: Gently press concrete around the thermometer According to ASTM C1064, what is one reason to take the temperature of concrete? Verify conformance 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) False The maximum allowable time between obtaining the first and last portions of the composite sample may not exceed 5 minutes. (T or F) False Start molding specimens for strength tests within 30 minutes after fabricating the composite sample. (T or F) False (15 mins) The composite concrete sample must be protected from sun, wind, contamination and rapid evaporation. (T or F) 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) False (wet screened) The composite sample not be remixed before beginning any tests. (T or F) False Sampling should normally be performed, as the concrete is discharged from the mixer. (T or F) True ASTM Method C172 includes the sampling from stationary mixers, paving mixers, truck mixers, agitators, and non-agitating equipment. (T or F) True After sampling is completed, start the tests for slump and air content within: a. 21/2 minutes b. 10 minutes c. 15 minutes d. None of the above In any case, do not obtain samples until: 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. 10%; 90% When strength tests are to be made, the minimum size of the composite sample shall be: 1 cubic foot