Interesting Remarks on the Comparison of Organomodified Nanomontmorillonites in Fibre-Cement Nanohybrids

This paper presents the effects of the addition of (i) the organomodified nanomontmorillonite (nMt) dispersion, nC2, produced for the scope of the FP7 project name FIBCEM and of (ii) the powder, undispersed organomodified industrially produced nMt, nC4 on quaternary nMt-fibre reinforced binders. The reference binder consisted of 60% Portland cement (PC), 20% limestone (LS) and 20% fly ash (FA). Superplasticizer was added at 2%, polyvinyl alcohol fibres at 3% and nMt was added at 1%. Flexural strength test were carried out at day 7, 28, 56 and 90 showed marginal enhancement offered by the nMt dispersion, which was attributed to limited, but existing additional pozzolanic reactivity of the particles of nMt. If fact, following methodology presented in published papers on other formulations, thermal gravimetric and X-ray diffraction analysis showed limited consumption of Ca(OH)₂ towards production of additional C-S-H, which is in line with the marginal increase of flexural strength for the same age of testing.