Consistency; Calibration Based Water Addition; Mixing - Hydronix Hydro-Control VI Operator's Manual

Optimisation

3 Consistency

A sensor measures moisture, not consistency.
Many factors affect consistency, but may not affect moisture content. These might include:
Aggregate grading (coarse/fine ratio)
•
Aggregate/cement ratio
•
Admixture dosage dispersion
•
Ambient temperature
•
• Water/cement ratio
• Ingredient temperature
• Colours

4 Calibration Based Water Addition

When calibrating, omit the admixtures, metal fibres and plastic fibres.
•
When performing a calibration it is advised that both the dry and wet mix times are
•
extended to ensure that both are homogeneous.
• A different calibration may be required for large variations in batch volume (e.g. half
batches).
• Calibrate when conditions and ingredients are typical e.g. not first thing in the morning
when the aggregates are very wet, or when the cement is hot.
When using a calibration-based water addition method, it is essential to obtain a correct
•
dry reading.
Dry mix time must be long enough to obtain stability of the signal.
•

5 Mixing

Minimum mix times are a function of the mix design (ingredients) not just the mixer.
•
Different mixes may require different mix times.
•
Keep batch sizes as consistent as possible e.g. 2.5m
•
3 x 2.0m .
3
In CALC Mode, keep the dry mix time as long as possible to allow the required water to be
•
calculated correctly, to the detriment of the wet mix time if necessary.
74 Hydro-Control VI Operators Guide HD0456 Rev 1.7.1
+ 2.5m + 1.0m is not as good as
3 3 3
Chapter 13