Morphology difference between the alkali activated cement and portland cement paste on multi-scale

Abstract

The features of alkali activated slag(AAS) and portland cement (PC) were observed on multi-scale, the crack and fracture sections were observed with naked eyes, and SEM and AFM were used to study the structure morphology differences between PC and AAS on micrometer to nano meter scale. The experimental results indicated that the AAS paste had soil like fracture texture and it was composed of mainly C-S-H gel but lacks of crystals, and it had a very strong tendency to shrink and crack. AAS paste is much denser and more homogeneous than PC, and on the nano scale C-S-H nano particle in the AAS paste is much smaller and packs much denser than PC paste.