Sampling
Before sampling concrete, verify the correct ___________ has been delivered to the jobsite before beginning tests for slump, air and temperature.
What is mix design?
This ratio is important to monitor when adding water to concrete in the field.
What is the water-to-cement ratio?
When performing the slump test, this size rod in diameter should be utilized.
What is 5/8"?
The air test by the pressurized method can be performed by completing how many lifts of concrete with how many rods each?
What is 3 lifts and 25 rods?
Rod 4x8 cylinders this many times per lift when casting cylinders in the field.
What is 25 times?
A composite sample should be sampled from this to truly be representative of the concrete being placed.
What is middle of the batch?
Along with the mix ID, this should be verified prior to sampling and is typically noted in the mix description of the batch/concrete delivery ticket.
What is specified strength?
You have this amount of time from start to finish to compete the slump test.
What is 2-1/2 minutes?
Report the air content to nearest ______ for air content <8% and to the nearest ______ for air content >8%.
What is 0.1% and 0.5%.
This is the amount of time to not exceed when transporting cylinders from the jobsite to the lab per ASTM C31.
What is 4 hours?
You have this amount of time to begin tests for slump, air and temperature after collecting your concrete sample.
What is 5 minutes?
The thermometer should be submerged a minimum of how many inches into the concrete sample within 5 minutes of sampling.
What is 3"?
The slump cone shall be calibrated this often according to ASTM C143.
What is annually?
The air meter shall be calibrated this often according to ASTM C231.
What is every 3 months?
These sized cylinders require 3 lifts of 25 rods when making and curing cylinders, can weigh around 28 pounds per cylinder, and can be a potential hazard using gravity as an energy source.
What are 6x12 cylinders?
This amount of concrete is the minimum amount required to cast cylinders and run tests for slump, air and temperature.
What is 1 cubic foot of concrete?
You have this window of time to record your concrete temperature result.
What is 2 to 5 minutes?
Report slump to the nearest ______ when reporting/recording test results.
What is 1/4"?
This is beneficial to concrete and is also an admixture for the durability of concrete between freeze-thaw environments.
What is air entrainment?
Use this to device to monitor the initial curing temperatures of standard lab cures stored in the field to maintain the concrete temperature between 60 and 80 degrees for concrete with a specified strength of less than 6000psi.
What is a hi-low or min-max thermometer?
Make sure to sample the concrete after all _____ and _____ have been added to the mix.
What is water and admixtures?
Report concrete temperature to the nearest _____.
What is 1 degree Fahrenheit?
The vertical distance between ________________ and _________________ of the top surface of the concrete is measured and reported as the slump of the concrete.
What is the the original and displaced position of the center?
Use the known volume of the air pot and calculate the mass of the concrete to determine this when testing for air.
What is unit weight density?
Use this when consolidating concrete with a slump of les than 1".
What is a vibrator?