Plaster of Paris hydration was viewed after 4 h, 7 h, 15.5 h, and 5 d.
Thus, cement particles will appear much brighter than hydration products, which will appear brighter than water-filled or air-filled porosity.
Different types of hydration products are seen to fill the initial water-filled space between the particles.
4, it is informative to view the greylevel histograms for the subvolumes as a function of hydration time.
Due to the higher w/c and the longer hydration time, there are fewer unhydrated cement particles in this image than in that for the w/c = 0.35 paste shown in Fig.