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The purpose of this thesis was to investigate the interaction between the Vinyl-Acetate Ethylene (VAE) latex stabilised with Polyvinyl Alcohol (PVOH) and Portland cement. This interaction was divided into three stages: (1) colloidal interaction at the beginning, (2) hydration of cement in the presence of polymers, and (3) film formation of the latex in cementitious environment. In the first stage, the colloidal interaction between two VAE latices stabilized by PVOH and Portland cement, including its main mineral phases, was investigated. The non-ionic VAE latex particles showed negative charge but had no affinity to Ca2+ by means of charge titration. Adsorption profiles were determined via the depletion method; the results indicated the analogous Langmuir type adsorption. The Zeta potential results showed a negligible effect of the VAE latex particles, indicating that the non-electrostatic interaction was dominant. Meanwhile, PVOH revealed preferential interaction with the aluminate phase. As a consequence, the strong interaction led to the flocculation of the latices in some extreme cases, e.g. in the C3A suspension. In the second stage, the divergent influence of the latex particles and PVOH on the hydration kinetics was confirmed by means of isothermal heat flow calorimetry, ICP-OES as well as in-situ XRD measurements. In accordance with the initial interaction, latex particles influenced the silicate phase hydration principally, while PVOH affected the aluminate hydration. Although the equilibrium concentration of SO42- was lower in the presence of polymers during the first few hours, the strong ‘sulfate depletion’ peak in the heat flow calorimetry was subjected to the enhanced reaction between the aluminate and sulphate carrier, which was hindered by PVOH at the beginning. In the third stage, the latex formed a film in the cementitious environment. Film formation was characterized in terms of its surface morphology, which was investigated by means of environmental scanning electron microscopy and atomic force microscopy. The coalescence of the polymer was indicated by its redispersibility. The latex films were stored under 85% relative humidity (R.H.), or coated on cement substrate under 50% R.H., or casted from the dispersions in synthetic cement pore solution (SCPS). Results showed that film formation was accelerated in the cementitious environment and that removal of PVOH in the vicinity of the latex particles by the interaction with cement was essential for polymer interdiffusion and coalescence.
The purpose of this thesis was to investigate the interaction between the Vinyl-Acetate Ethylene (VAE) latex stabilised with Polyvinyl Alcohol (PVOH) and Portland cement. This interaction was divided into three stages: (1) colloidal interaction at the beginning, (2) hydration of cement in the presence of polymers, and (3) film formation of the latex in cementitious environment. In the first stage, the colloidal interaction between two VAE latices stabilized by PVOH and Portland cement, including its main mineral phases, was investigated. The non-ionic VAE latex particles showed negative charge but had no affinity to Ca2+ by means of charge titration. Adsorption profiles were determined via the depletion method; the results indicated the analogous Langmuir type adsorption. The Zeta potential results showed a negligible effect of the VAE latex particles, indicating that the non-electrostatic interaction was dominant. Meanwhile, PVOH revealed preferential interaction with the aluminate phase. As a consequence, the strong interaction led to the flocculation of the latices in some extreme cases, e.g. in the C3A suspension. In the second stage, the divergent influence of the latex particles and PVOH on the hydration kinetics was confirmed by means of isothermal heat flow calorimetry, ICP-OES as well as in-situ XRD measurements. In accordance with the initial interaction, latex particles influenced the silicate phase hydration principally, while PVOH affected the aluminate hydration. Although the equilibrium concentration of SO42- was lower in the presence of polymers during the first few hours, the strong ‘sulfate depletion’ peak in the heat flow calorimetry was subjected to the enhanced reaction between the aluminate and sulphate carrier, which was hindered by PVOH at the beginning. In the third stage, the latex formed a film in the cementitious environment. Film formation was characterized in terms of its surface morphology, which was investigated by means of environmental scanning electron microscopy and atomic force microscopy. The coalescence of the polymer was indicated by its redispersibility. The latex films were stored under 85% relative humidity (R.H.), or coated on cement substrate under 50% R.H., or casted from the dispersions in synthetic cement pore solution (SCPS). Results showed that film formation was accelerated in the cementitious environment and that removal of PVOH in the vicinity of the latex particles by the interaction with cement was essential for polymer interdiffusion and coalescence.
Interaction between vinyl acetate-ethylene latex stabilized with polyvinyl alcohol and Portland cement
Wechselwirkung zwischen Vinylacetat-Ethylen Polymerdispersionen mit Polyvinyl-Alkohol als Schutzkolloid und Portlandzement
Jin, Yu (author)
2016
Miscellaneous
Electronic Resource
English
Filmbildung , EVA , PVOH , film formation , PVA , VEA , hydration , Zement , Hydration , cement
DDC:
691
| British Library Online Contents | 2018
Polyvinyl Acetate and Portland Cement Mortars
| ASCE | 2021
Polyvinyl acetate and Portland cement mortars
| Engineering Index Backfile | 1960