As mentioned earlier, the purpose of this research was to evaluate
the impact of different OC, grouped according to d001 and different
functional group of modifier, on the properties of cement
paste. Since cement was partially replaced by OC, the microstructure
analysis of the samples was performed. The SEM micrographs
are shown in Fig. 2. The fracture surface of the plain cement paste
(PC) consists of a combination of smooth and rough areas typical of
fracture features of cement based materials (Fig. 2a and c).
Although no plasticizer or dispersing agent was used to avoid OC
agglomeration, in the contrast to [11], large (30–50 lm) OC grains
were not found, possibly due to long OC mixing with water performed
in this study (Fig. 2b). Since surface of OC particle is extended with unclosed lamellas