Precise moisture measurement in aggregates eliminates the mixer probe

Sono-Vario aggregate probes at the production plant of HOLCIM GmbH in Stuttgart/Germany

The diagram shows a data comparison of kiln drying moisture values to the measurement values of Sono probes. In different aggregates and moisture ranges an averaged accuracy of ±0,1% is met

The Sono-Vario Xtrem with an exchangeable hardened steel probe head. Green shows the radar wave

With TDR a travel time of an electromagnetic radar pulse stands in relation to the dielectric constant ε which represents the water content in aggregates

There are significant benefits if concrete recipes can comply with tolerances of about ±2 liter water per m3 by sole use of aggregate sensors.

The quality of fresh concrete is essential for stability and durability of concrete products. To fulfill the compliance with concrete recipes the precise measurement of aggregate moisture plays an important role. Dependent on concrete type accuracies of ±10 liters up to ±2 liters are required to meet standards and to guarantee the quality of final products.

For the manufacture of ready mixed concrete it was content up to now, to measure only the sand moisture in order to control the water dosage, with the aim that a plant is running with a tolerance of about ±5 to 10 liters per m³. For...