Methods, systems, and apparatus, including computer programs encoded on computer storage media, for preparing a concrete mixture. One of the methods includes controlling an ingredient metering system to measure and add a plurality of ingredients to a concrete mixture, measuring characteristics of at least one ingredient of the ingredients using a particle analyzer, determining an estimated rheometry measurement of for the concrete mixture, obtaining an actual rheometry measurement of the concrete mixture, and selectively controlling the ingredient metering system to add one or more additional ingredients to the concrete mixture based on a comparison of the estimated rheometry measurement with the actual rheometry measurement.