Which units are commonly used for temperature, slump, and air content in field testing?

• A. Temperature in degrees Celsius or Fahrenheit, slump in inches (or millimeters), and air content as a percentage.
• B. Temperature in Kelvin, slump in feet, air content in psi.
• C. Temperature in Rankine, slump in centimeters, air content in liters.
• D. Temperature in Celsius, slump in gallons, air content in bar.

Answer: (A)

In field testing, the units chosen are those that align with practical measurement methods and reporting conventions. Temperature is given in degrees Celsius or Fahrenheit so crews can compare readings directly to mix specifications and curing conditions used in the project. Slump measures the workability of the concrete and is read from a slump cone in inches in the United States, with millimeters used in metric contexts; this directly reflects the depth of subsidence observed. Air content represents the fraction of air voids in the concrete, so it’s reported as a percentage of the total volume to express how much air is present.

Other unit choices don’t fit typical field practice: Kelvin or Rankine aren’t used in construction field testing; using feet for slump would mischaracterize the measurement, and reporting air content in pressure units like psi or bar mixes concepts that don’t apply to the volume fraction of air.