Slump Retention Calculator
Turn two measured slump points into an observed loss, retained percentage and time-normalized rate for trial comparison.
Measured values
No forecast is generated
Slump loss is rarely linear and depends on temperature, cement compatibility, mixing, transport and test repeatability. The result describes only the two entered observations.
Formula and trial discipline
Use identical sampling, remixing and test procedures when comparing admixture trials.
Loss = initial slump − later slump
Retention = later slump ÷ initial slump × 100
Observed rate = loss ÷ elapsed minutes
Retention = later slump ÷ initial slump × 100
Observed rate = loss ÷ elapsed minutes
- Record concrete temperature at both measurements.
- Record elapsed time from a consistent reference point.
- Repeat the measurement when the result conflicts with the concrete appearance.