Abstract
The particles’ cohesion and dispersion states in the mixing process of cement paste with low water-to-binder ratio were evaluated quantitatively as the base for the estimation of the properties of the mixing of ultra-high-strength concrete. The screening tests and the measurements of particle size distribution were conducted at the stage where the materials are powdery and the SEM-EDS mapping analysis and the image analysis were practiced at the stage where the materials change from clay-like states to pastes. The results show that the behavior of particles’ cohesion and granulation makes progress and indicate that the properties of the mixing of the cement paste concerned have a relation to granulation speed of the binder at the former stage, and show that the agglomerates of silica fume and fly ash in the cement paste gets loose and dispersed as the mixing goes on at the latter stage. The results also indicate that difference of the types of the mixer has no little effect on the particles’ dispersion states at the end of mixing process when the dispersion indexes of silica fume and fly ash in the cement paste with paddle type mixer are compared with those in the cement paste with double mixer.
