Method and device for composing a sand mixture for concrete, and sand mixture and concrete thus obtained

摘要

The invention relates to a method and device for composing fine aggregates for concrete, to fine aggregates composed in this way and concrete produced therewith, and also to methods for determining the conductivity ratio of a sand and for measuring viscosity of concrete produced therewith.;The invention is based on the insight that the conductivity ratio of a sand, i.e. the electrical conductivity of a mixture of the said sand in a liquid divided by the electrical conductivity of the liquid, is a significant indicator for predicting the viscosity properties of concrete produced using the corresponding sand. Matching the conductivity ratio to an ideal value for the said sand also allows the viscosity to be minimized. The conductivity ratio can be matched, for example, by mixing with another suitable sand grade, in particular a fine sand grade, or altering the salt content.