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State of Water in Hydrating Tricalcium Silicate and Portland Cement Pastes as Measured by Quasi‐Elastic Neutron Scattering
Author(s) -
Thomas Jeffrey J.,
FitzGerald Stephen A.,
Neumann Dan A.,
Livingston Richard A.
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb00919.x
Subject(s) - portland cement , bound water , silicate , population , materials science , neutron scattering , exothermic reaction , phase (matter) , calcium silicate , calcium silicate hydrate , mineralogy , hydrate , cement , composite material , chemistry , chemical engineering , thermodynamics , neutron , organic chemistry , molecule , demography , physics , quantum mechanics , sociology , engineering
Quasi‐elastic neutron scattering (QENS) was used to monitor the state of water in portland cement and tricalcium silicate pastes during the first 2 days of hydration at three different temperatures. By applying a double‐Lorentzian rather than a single‐Lorentzian fitting function, the QENS signal from water at a given hydration time was divided into three separate populations arising from liquid water, chemically bound water, and constrained water. The constrained water population consisted of water adsorbed on surfaces and contained in very small (<10 nm) pores, and could be associated primarily with the calcium‐silicate‐hydrate (C‐S‐H) phase. The rate of increase in the chemically bound water population closely followed the exothermic heat output, while the constrained water population increased more rapidly during the first several hours of hydration and then leveled off.