Monitoring of concrete mixing evolution using image analysis

The improvement of inline mixer measurements is imposed in a growing concrete industry employing increasingly complex manufacturing processes. In this work we discuss an inline image analysis technique applied to the monitoring of concrete mixing, which is based on the evolution of the texture of pictures taken at the surface of the mixing bed. The method is used to study the evolution of the paste during processing in an intensive laboratory scale mixer for three different formulations: a hard-to-mix concrete, a self-compacting mortar and an easy to mix cement paste. The evolution of the texture allows obtaining important information on the evolution of the different formulations during mixing; in addition, the technique allows identifying with a good repeatability the main characteristic points of the mixture evolution, i.e. the cohesion time and the fluidity time.