CSLB General Building (B)Site Work, Foundations and ConcreteMedium
A ready-mix concrete truck arrives at a jobsite, and the field technician performs a slump test before the pour begins. What does this test primarily measure?
- AThe air content trapped in the concrete
- BThe workability and consistency of the fresh concrete mix
- CThe compressive strength of the hardened concrete
- DThe curing temperature of the concrete during hydration
Show answer & explanationAnswer & explanation
Correct answer: B. The workability and consistency of the fresh concrete mix
The slump test measures the consistency and workability of fresh concrete by observing how much a cone-shaped sample settles after the mold is removed. It does not measure strength, air content, or temperature directly.
Why the other options are wrong
- A. Air content is measured separately with an air meter/pressure gauge.
- C. Compressive strength is measured later using cured test cylinders, not the slump test.
- D. Curing temperature is monitored with thermometers or maturity meters, not a slump cone.
Slump Test
A field test measuring the workability and consistency of fresh concrete by the amount a cone-shaped sample slumps after mold removal.
- Performed on fresh, unhardened concrete
- Uses a standard slump cone (12 inches tall)
- Higher slump indicates wetter, more workable mix
Memory trick: Slump shows the 'slop' — how workable the mix is.