Effects of Organo-Modified Layered Silicates on the Microstructure and Properties of Cement Mortars
| Autor: | Wen-Yi Kuo, 郭文毅 |
|---|---|
| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 In this study, layered silicates, which are lamellar solids that can incorporate guest species into the galleries between their layers, are used as reinforcements and fine aggregates in cement mortars after they are organo-modified. Organo-modified montmorillonites (OMMT) which have been widely used in polymer/clay nano-composites are employed here as fillers and reinforcements in cement mortars. Experimental results indicate that the coefficients of permeability of cement mortars could be 100 times lower if a lower dosage of OMMT micro-particles is added. At the same time, the compressive and flexural strengths of cement mortars can be even increased up to 40% and 10%, respectively. It is also found that the optimal dosage of OMMT micro-particles to give higher compressive and flexural strengths and a lower coefficient of permeability for cement mortars is less than 1%. Furthermore, reservoir sludge in Taiwan mainly composed of smectite clay is first organo-modified. Organo-modified reservoir sludge (OMRS) particles are employed here as a substitute for a portion of fine aggregates in cement mortars. Experimental results indicate that it could be possible to replace up to 30% by weight of fine aggregates by OMRS particles in a cement mortar for normal practice. Also, excellent waterproof of cement mortars is achieved when the percentage of OMRS particles is within the range of 5~50%. The effects of OMMT and OMRS particles on microstructure of cement mortars are evaluated and discussed. Accordingly, the optimum dosages of OMMT and OMRS particles introduced in cement mortars with different water/cement ratios to enhance their microstructure and mechanical properties are proposed here. It is expected that this preliminary research can provide more physic insights before the organo-modified layered silicates are applied to modern concretes. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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