R. Vocka et al., Mercury intrusion porosimetry and hierarchical structure of cement pastes - Theory and experiment, CEM CONCR R, 30(4), 2000, pp. 521-527
We developed a mercury intrusion porosimetry (MIP) simulator that takes int
o account the hierarchical structure of the porosity in certain materials (
e.g., cement paste). We show that pore diameters indicated by the MIP resul
ts depend not only on the pore size distribution in the sample, but also on
the connectivity of the pore space. On the basis of our simulations, we in
terpret experimental data obtained for cement pastes with and without a rea
ctive admixture. The MIP data show that the capillary porosity fur the pure
paste is connected, even for the water/cement ratio w/c = 0.30, at varianc
e with the Powers-Brownyard model of hydration. Our experimental results ar
e in accordance with observations that the hydration process fixes the morp
hology of the hydration product. This morphology does not evolve continuous
ly with w/c, only with the fraction of C-S-H corresponding to a given morph
ology evolves. (C) 2000 Elsevier Science Ltd. All rights reserved.