This paper presents the results of an experimental investigation carried out to evaluate the microstructure, hydration and nanomechanical properties of concrete containing metakaolin. The properties of concrete containing metakaolin at 0%, 5%, 10% and 15% by mass of cement were studied for their compressive strength, sorptivity and carbonation resistance at two different water-binder ratios. It was found that 10% of the Portland cement could be beneficially replaced with the metakaolin to improve the sorptivity and carbonation resistance of concrete. In order to have a better understanding of the microstructure, hydration and nanomechanical properties various analytical techniques such as XRD, MIP and nanoindentation studies were carried on cement paste samples (with and without 10% MK). Test results showed that the incorporation of metakaolin modifies the cement paste in four different ways. Firstly, by transforming portlandite into C-S-H gel by means of pozzolanic reaction, secondly by reducing the porosity, thirdly by creating nucleation sites for hydration and finally, by modifying the relative proportions various phases of C-S-H gel.
- Compressive strength
ASJC Scopus subject areas
- Civil and Structural Engineering
- Building and Construction
- Materials Science(all)