Evaluación de la reactividad puzolánica de la ceniza de paja de arroz
The purpose of this aim is to determine the pozzolanic properties, as well as the physical and chemical characteristics of rice straw ash for use as an admixture in concrete mixtures with Portland cement. A material is classified as pozzolanic, when in the presence of water, it is able to react with...
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| Formato: | tesis de maestría |
| Fecha de publicación: | 2018 |
| País: | España |
| Recursos: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | español |
| OAI Identifier: | oai:riunet.upv.es:10251/105638 |
| Acesso em linha: | https://riunet.upv.es/handle/10251/105638 |
| Access Level: | acceso abierto |
| Palavra-chave: | Ceniza de paja de arroz Puzolana Residuo Resistencia mecánica Termogravimetría Rice straw ash Pozzolan Residue Mechanical strength Thermogravimetry Frattini INGENIERIA DE LA CONSTRUCCION Máster Universitario en Ingeniería del Hormigón-Màster Universitari en Enginyeria del Formigó |
| Resumo: | The purpose of this aim is to determine the pozzolanic properties, as well as the physical and chemical characteristics of rice straw ash for use as an admixture in concrete mixtures with Portland cement. A material is classified as pozzolanic, when in the presence of water, it is able to react with calcium hydroxide produced in the hydration of Portland cement, to generate compounds of a similar nature to those formed in the hydration of cement. They usually present silica and amorphous alumina in their chemical composition. Rice husk ash has been deeply researched as pozzolan. However, perhaps due to its lower silica content, rice straw ash has not been used as much, although according to the FAO, the production of this rice straw is estimated at around 600 million tons per year. It is usually burned outdoors, or incorporated as organic fertilizer and fodder for animals. A controlled burn was carried out at the ICITECH facilities of rice straw, obtaining ash. Firstly , the ash was conditioned, consisting of the removal of the top layer burned, because it contains a lot of carbon as a consequence of an incomplete combustion, and secondly a homogenization and grinding of the rest of the sample, in order to obtain an optimum granulometry for carrying out the tests. The first step was to carry out chemical tests: chemical composition, dissolved salts, chlorides, insoluble residue and conductivity and pH in aqueous suspension. Physical parameters such as density were also measured and a granulometric study was carried out to estimate the most convenient granulometry. In addition, scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (FTIR) tests were carried out. For the evaluation of pozzolanic reactivity of rice straw ash, Frattini tests were carried out, conductivity tests and pH in aqueous suspension lime / ash and lime / CPA and cement / CPA pastes, for evaluation by thermogravimetry. Finally, control Portland cement mortar and Portland cement samples were produced with cement replacement by CPA (between 0-30%) and their mechanical resistance to flexural and compression at different days was evaluated. The results found were satisfactory for replacement percentages between 10-30%. These results have been compared by those found in the literature with rice husk ash, in order to generate a better profile of this material, as a pozzolanic addition in the manufacture of Portland cement mortars |
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