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Showing 1 to 20 of 37 for “"Calcium Silicate Hydrate"”.
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Characterization of calcium-silicate-hydrate and calcium-alumino-silicate-hydrate
… objectives of this thesis were to synthesize calcium silicate hydrate (C-S-H) and calcium aluminosilicate hydrate (C-A-S-H) and characterize their structures with varying Ca/Si ratios and aluminum content. As a secondary objective, carbonation behavior in synthesized C-S-H was studied. C-S-H …
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Synthesis and nano-mechanical characterization of calcium silicate hydrate (C-S-H)
Calcium Silicate Hydrate (C-S-H) constitutes two-thirds of hydrated cement paste by volume. Having a better understanding of the mechanical properties of C-S-H will significantly aid in future effort for making concrete by design' for specific applications such as blast resistance. C-S-H is an …
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Probing water properties and cationic exchange in calcium-silicate-hydrate : an atomistic modeling study
… in the nano-pores of the highly disordered calcium-silicate-hydrate (C-S-H) which is the major binding phase of cement. The microscopic structure and dynamics of water confined in C-S-H have important implications on describing the cohesion and mechanical behavior of cement from its setting …
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Synthesis and Multi-Scale Characterization of Calcium Silicate Hydrate at Multiple CaO/SiO2 Mixture Ratios
Calcium Silicate Hydrate (C-S-H) is the primary binding agent that is responsible for setting and hardening, strength, dimensional stability, and durability of Portland cement paste. Although Portland cement hydration produces C-S-H, Calcium hydroxide (CH), ettringite, and other hydration products …
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Silicon-29 and oxygen-17 nuclear magnetic resonance investigation of the structure of calcium-silicate-hydrate
This thesis investigates the structure of calcium-silicate-hydrate (C-S-H), a major hydration product of Portland cement, using primarily $\sp{29}$Si and $\sp{17}$O MAS and $\sp1$H-$\sp{29}$Si CPMAS NMR, XRD, chemical and thermal analysis. It presents a comprehensive defect-tobermorite structural …
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Molecular Crosslinking of Calcium-Silicate-Hydrate with Organosilanes: Toward Engineering of Cementitious Matrices with High Thermal Resistance
… phenomena in which the galleries of inorganic calcium-silicate-hydrate (C-S-H), the main product of cement hydration, are directly bridged with bis-organosilanes molecules. The crosslinking with organic molecules provides C-S-H with attributes imperative for the reduced thermal conductivity …
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Calcium-Silicate-Hydrate in cementitious systems : chemomechanical correlations, extreme temperature behavior, and kinetics and morphology of in-situ formation
… material. A fundamental component known as Calcium-Silicate-Hydrate which forms from the reaction between cement and water is the binding phase in concrete. Curiously, this is the least understood component of concrete because of its porous amorphous structure. Further, beyond mere …
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Understanding the role of slag on geopolymer hardening and microstructural development
… obtained by using Class F flyash/slag/K-silicate/H2O. This involves the use of low concentration alkaline activators and low-temperature curing. A detailed investigation of microstructural development and hardening rate was presented for flyash and slag based geopolymers. Flyash and slag …
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Understanding effects of silicon/aluminum ratio and calcium hydroxide on chemical composition, nanostructure and compressive strength for metakaolin geopolymers
… to determine the effects of the Si/Al ratio and calcium hydroxide on the chemical composition and nanostructure for metakaolin geopolymers. The second was to determine how the composition and nanostructure correlate with mechanical properties of the geopolymer. For this study, the geopolymers …
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First principles simulation of cement for nuclear waste disposal
… demonstrate that the nanoscale structure of calcium silicate hydrate does not notably influence the structure of the defects that form when cement interacts with ionizing radiation. In particular, we show that electrons locate in the water- and calcium-rich interlayer region, where they may …
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Characterizations of concretes with alkali-activated binder and correlating their properties from micro- to specimen level
… AAB is produced by alkali activation of aluminosilicate compounds as precursors with or without calcium ions in them in the temperature range of 60° C to 90° C. Since most of the precursors are waste or by-products, the AAB is regarded as sustainable and green construction material with …
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Nano-ChemoMechanical assessment of Rice Husk Ash cement by wavelength dispersive spectroscopy and nanoindentation
… with portlandite to form different types of calcium silicate hydrate (C-S-H). It is found that C-S-H in RHA cement has lower Ca/Si ratios compared to pure ordinary portland cement (OPC) samples prepared under the same conditions. Incorporation of RHA has minor effect on the mechanical …
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Investigation of Shrinkage Mechanisms in Hydrated and Carbonated Tricalcium Silicate Systems
… determinations, were obtained on fully hydrated tricalcium silicate (C(,3)S) paste that had original water/cement (w/c) ratios of 0.4 and 0.6. The surface area of the calcium silicate hydrate (C-S-H) phase determined by water is considered to be the single most important microstructural …
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Sulfate attack on cement paste with volcanic ash : durability analysis
… 30 days. The effect of gradual decomposition of calcium-silicate-hydrate (C-S-H) gel was examined using Raman spectroscopy and Magic Angle Nuclear Magnetic Resonance (MAS NMR), while the mechanical properties were determined using nanoindentation and compression tests. Exposure to magnesium …
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Non-equilibrium thermodynamics in porous media : battery degradation, and sorption and transport in porous materials
… to water inserted between molecular layers in calcium-silicate-hydrate. Finally, I outline a model of transport of a sorbing fluid with hysteresis, and suggest possible extensions to allow quantitative comparison with experimental results.
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Phosphate-doped borosilicate enamel coating used to protect reinforcing steel from corrosion
<p>"Phosphate-doped sodium borosilicate glasses were developed for enamel coatings to provide corrosion protection for reinforcing steel in concrete. Phosphates have low solubilities in borosilicate glasses, generally less than about 4 mol%, and are incorporated mainly as isolated …
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Effects of elevated temperature exposure on cement-based composite materials
… x-ray analysis (SEM-EDS). Thermal degradation of calcium silicate hydrate (C-S-H) is assessed based on AFM image analysis and a statistical analysis of static and dynamic nanoindentation. Furthermore, the application of combined nanoindentation/SEM-EDS successfully overcomes the difficulty of …
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Structure and Mechanical Properties of Cement and Intermetallic Compounds via ab-initio Simulations
Calcium silicate hydrates comprise a class of minerals formed synthetically during Portland cement hydration or naturally through various geological processes. The importance of these minerals is immense since they are the primary binding phases for Portland cement derived construction materials. …
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Setting and nanostructural evolution of metakaolin geopolymer
… to be substantially accelerated by addition of calcium. The objective of this study is to understand the setting at the nanostructural level for calcium and non-calcium geopolymers using a relatively pure aluminosilicate metakaolin precursor. Prior to probing nanostructural evolution, a …
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