Page 9 - November-2022

TECHNICAL PAPER

silicate hydrate (C-S-H) gels [33] also have moderate increase in 3.4 Pore structures
the references at 365 days relative to the endothermic peak at
90 days, which verifies highlighted rehydration occurred in UHPC Figure 6 and Figure 7 furnish the pore size distributions
pate. and porosity for UHPC pastes with long term water curing,
respectively. In addition, its volume fraction of pores with
Additionally, hydration product monocarboaluminate (MC) different size ranges of pastes are presented in Figure 8.
phase revealing synergism of MK and LS [34] can not be measured According to Figure 6 and 7, the most critical diameter of MK
distinctly in ternary paste blended with MK and LS (PLS15) in blended mixtures are obviously smaller than that of the control
terms of Figure 5(b). Moreover, its diffraction peak intensity of pastes both at 90 and 365 days attributed to MK reaction. And
Mc for LS cement mixture (PLS00) also has not distinct growth the porosity of pastes without LS at 365 days has measurable
at 365 days relative to the diffraction peak intensity at 90 days. degradation compared with the porosity at 90 days. While
Therefore, basing on the investigated results in this study, LS the porosity of ternary paste CLS15 at 365 days presents an
only serves as filler and it hardly participates in the rehydration growth compared with the porosity at 90 days, which accounts
reaction including synergistic reaction with MK in pastes with for the slight degradation of compressive strength from 90 to
long term water curing. 365 days. In terms of Figure 8, pores under 10 μm of all pastes

(a) Pastes without LS (b) Pastes blended with LS
Figure 6: Pore size distribution of pastes under long term water curing

a) Pastes without LS ((b) Pastes blended with LS
Figure 7: Porosity of pastes under long term water curing

THE INDIAN CONCRETE JOURNAL | NOVEMBER 2022 23