For the twelve batches, the experimental mixer power consumption evolution with respect to time. The indicated operation time includes the loading of the . The loading sequence generates an increase in power consumption.
Once the concrete mixer completely charged, the power consumption has a first peak. Constituents' loading is followed by a second power peak for batches with lower water dosage. The power then decreases and a relative stabilization
occurs.
The data acquisition being of only one measurement per second, fluidity points are harder to detect by a power fluctuation analysis. However, the example corresponding to the batch with 169 l/m3 of total water shows that the method is
still discriminate. The figure also represents the second peak of the power curve. Complementary analysis based on three concrete mixer sensors confirms that the second power peak corresponds to the maximum cohesion point.
The fluidity and maximum cohesion points may be fitted respectively by a fluidity line and a maximum cohesion line. The concavity of the maximum cohesion line is changed compared to the UHPSCC case mixed in . It may be assumed that the two lines intersect at the end of liquid loading, in the hypothetic case of a very large amount of added water (the mixture became directly a suspension without a hard paste stage). So, the power to time chart is divided
in three domains. As previously indicated, the state of mixture before the maximum cohesion line is mostly wet granular; between the two characteristic lines the mixture is a hard paste and becomes a granular fluid after the fluidity line.
