A thermodynamic model for C-(N-)A-S-H gel: CNASH{sub s}s. Derivation and validation

Journal Article · Mon Dec 15 00:00:00 EST 2014 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2014.07.005· OSTI ID:22395932

Myers, Rupert J.; Bernal, Susan A.

The main reaction product in Ca-rich alkali-activated cements and hybrid Portland cement (PC)-based materials is a calcium (alkali) aluminosilicate hydrate (C-(N-)A-S-H) gel. Thermodynamic models without explicit definitions of structurally-incorporated Al species have been used in numerous past studies to describe this gel, but offer limited ability to simulate the chemistry of blended PC materials and alkali-activated cements. Here, a thermodynamic model for C-(N-)A-S-H gel is derived and parameterised to describe solubility data for the CaO–(Na{sub 2}O,Al{sub 2}O{sub 3})–SiO{sub 2}–H{sub 2}O systems and alkali-activated slag (AAS) cements, and chemical composition data for C-A-S-H gels. Simulated C-(N-)A-S-H gel densities and molar volumes are consistent with the corresponding values reported for AAS cements, meaning that the model can be used to describe chemical shrinkage in these materials. Therefore, this model can provide insight into the chemistry of AAS cements at advanced ages, which is important for understanding the long-term durability of these materials.

• OSTI ID: 22395932
• Journal Information: Cement and Concrete Research, Vol. 66; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
ALUMINIUM OXIDES
CALCIUM OXIDES
CALCIUM SILICATES
CHEMICAL COMPOSITION
DENSITY
GELS
HARDNESS
HYBRIDIZATION
HYDRATES
PORTLAND CEMENT
SHRINKAGE
SILICA
SILICON OXIDES
SIMULATION
SLAGS
SODIUM OXIDES
THERMODYNAMIC MODEL
VALIDATION
WEAR RESISTANCE