The influence of particle size on the pozzolanic reactivity of quartz powder

Pozzolanic activity and filler effect of sugar cane bagasse ash in Portland cement and lime mortars

“…This contrasts with results from Kitamura et al [22] from grinding of Al(OH) 3 and from Palaniandy et al [16] from oscillating grinding of silica that show evidence of amorphization at grinding times that are comparable to the ones used in the present study. It is important to note that an increase in compressive strength of mortars generated by vibratory grinding of the silica powder was observed by Benezet and Benhassaine [23]. However, no structural changes in silica could be detected, and the authors pointed out that the crystalline structure of silica can not be considered as an obstacle to its reactivity with lime, since the particles are of very fine sizes.…”

Rapid screening tests for supplementary cementitious materials: past and future

“…This is due to the formulation of the simplified system in supplying more portlandite and water, and because of the wellknown higher apparent activation energy of the SCM reaction compared to the cement hydration reactions. Benezet and Benhassaine [9], for example, reported an apparent activation energy for the pozzolanic reaction of silica fume of 83 kJ/mol, this would correspond to an acceleration factor of 8.8 for reactions at 40 versus 20°C. In practice, this means that the 28 days compressive strength results are predicted using the cumulative heat after 2.8 days (19.2 h) of reaction.…”

“…To overcome this problem, the common approach was to raise reaction temperatures [5,6]. The Chapelle test [7] and its later modifications [8] are the most widely used examples of this approach by measuring the consumption of portlandite in a SCMportlandite suspension after boiling overnight [9][10][11].…”

Stabilization of NaCl-containing cuttings wastes in cement concrete by in situ formed mineral phases

“…For the sake of simplicity the latter will be called "potassium, calcium and aluminium phosphate" all along this paper. Addition of quartz aimed at improving the cement setting and mainly occurs as an additive that acts as a mass diluting compound of the total salt content in the specimens, though, <5 m quartz particles are subject to pozzolanic reactions [35]. …”

“…The results clearly state that sodium does not affect the hydration process, while chloride quickly disappears due to chemical reactions with the cement components. In fact, 35 Cl spectroscopy showed that only solid or adsorbed chloride is observed and that chloride ions are absent after drying [3].…”