Inelastic neutron scattering investigation of hydrating tricalcium and dicalcium silicate mixture pastes: Ca(OH)2 formation and evolution of strength

2006 ◽  
Vol 21 (7) ◽  
pp. 1836-1842 ◽  
Author(s):  
Vanessa K. Peterson ◽  
Dan A. Neumann ◽  
Richard A. Livingston
Keyword(s):  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Vibrational Mode ◽  
Inelastic Neutron ◽  
Dicalcium Silicate ◽  
Strength Testing ◽  
Hydration Products ◽  
Quasielastic Neutron ◽  
Quasielastic Neutron Scattering ◽  
Formation And Evolution

The hydration of controlled tricalcium and dicalcium silicate mixtures was investigated using inelastic neutron scattering. The amount of Ca(OH)2 produced by each mixture was quantified based on the vibrational mode at approximately 41 meV. The results of compressive strength testing correlate with the amount of Ca(OH)2 produced and with previous results from quasielastic neutron scattering. These results establish a link between hydration mechanics and the evolution of hydration products leading to desirable properties, such as strength.

NH3 reorientation in phases I, II, and III of Ni(NH3)6(NO3)2

1988 ◽  
Vol 66 (4) ◽  
pp. 692-697 ◽  
Author(s):  
Gordon J. Kearley ◽  
Herma Blank
Keyword(s):  
Phase Transition ◽  
Neutron Scattering ◽  
Strong Interaction ◽  
Rotational Motion ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Phase Iii ◽  
Single Type ◽  
Quasielastic Neutron ◽  
Quasielastic Neutron Scattering

The inelastic neutron scattering (INS) spectra of rotational tunnelling and librations of NH3 ligands in phase III of Ni(NH3)6(NO3)2 are not consistent with a rotational hindrance potential containing only cos [Formula: see text] terms owing to strong interaction between neighboring cations. This type of interaction, and motion of the whole cation, also influences the classical reorientational motions involving displacement of the H atoms, where the overall radius of rotation is consistently greater than the 0.9 Å expected for isolated NH3 rotors. Quasielastic neutron scattering (QNS) suggests that in phase III there are two sublattices of cations, one of which becomes completely disordered (with respect to the NH3 rotors) at the III–II phase transition. Disorder of the second sublattice marks the II–I transformation where only a single type of rotational motion is found.

Interactions of Hydrating Tricalcium and Dicalcium Silicate using Time-Resolved Quasielastic Neutron Scattering

2004 ◽  
Vol 840 ◽  
Author(s):  
Vanessa K. Peterson ◽  
Dan A. Neumann ◽  
Richard A. Livingston
Keyword(s):  
Neutron Scattering ◽  
Growth Period ◽  
Dicalcium Silicate ◽  
Reaction Products ◽  
Time Resolved ◽  
Hydration Rate ◽  
Two Factors ◽  
Quasielastic Neutron ◽  
Hydration Model ◽  
Quasielastic Neutron Scattering

ABSTRACTHydrating tricalcium and dicalcium silicate mixtures were studied using time-resolved quasielastic neutron scattering. Application of a hydration model allowed the extraction of several parameters describing the hydration mechanics. The hydration rate during the nucleation and growth period, diffusivity during the diffusion limited regime, and the maximum amount of product able to be formed were not related linearly to the mixture combinations. Addition of dicalcium silicate at approximately 20 wt. % caused a sharp alteration to these parameters, including reduced hydration rate and reaction layer permeability. These two factors lead to the prediction that more reaction products would be ultimately manufactured during the reactions at this composition.

From crystal to glass-like thermal conductivity in crystalline minerals

2015 ◽  
Vol 17 (30) ◽  
pp. 19751-19758 ◽  
Author(s):  
Y. Bouyrie ◽  
C. Candolfi ◽  
S. Pailhès ◽  
M. M. Koza ◽  
B. Malaman ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Neutron Scattering ◽  
Single Crystals ◽  
Inelastic Neutron Scattering ◽  
Vibrational Mode ◽  
Inelastic Neutron ◽  
Low Energy ◽  
Chemical Environment

Inelastic neutron scattering performed on powders and single crystals indicate that the glass-like thermal conductivity of tetrahedrite minerals originates from a strongly anharmonic low-energy vibrational mode related to the peculiar chemical environment of the Cu2 atoms.

Inelastic neutron scattering study of the hydration of tricalcium silicate

1999 ◽  
Vol 14 (3) ◽  
pp. 1160-1165 ◽  
Author(s):  
S. A. FitzGerald ◽  
D. A. Neumann ◽  
J. J. Rush ◽  
R. J. Kirkpatrick ◽  
X. Cong ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Calcium Hydroxide ◽  
Inelastic Neutron Scattering ◽  
Free Water ◽  
Inelastic Neutron ◽  
Tricalcium Silicate ◽  
Curing Temperature ◽  
Water Index ◽  
Quasielastic Neutron ◽  
Neutron Scattering Study

Inelastic neutron scattering is applied for the first time to monitor directly the concentration of calcium hydroxide formed during the hydration of tricalcium silicate. Results taken between 10 and 40 °C show that the onset of calcium hydroxide formation is delayed at lower temperatures but that the final quantity formed appears to be converging to a temperature-independent value. At 20°C, the 28 day value is 1.3 moles per mole of tricalcium silicate. Combining these results with previous measurements of the free water index made using quasielastic neutron scattering reveals that the hydrogen content of the C–S–H gel decreases significantly at increased curing temperature.

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