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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Influence of PET fibers on compressive strength, water absorption percentage and density of adobe

Ordoñez, Denys, Noa, Melisa, Carrera, Elsa 01 January 2022 (has links)
Adobe is a building material that has been used since ancient times, but is not as widely used as clay bricks or concrete for housing construction. In addition, it uses a construction technique that has been passed down and improved from generation to generation. In view of this, the present work aims to improve the properties of adobe by using PET bottle fibers in its composition. A mechanical test and two physical tests were carried out for adobe with 0% (standard adobe), 2%, 4% and 6% PET fibers, where it was observed that the adobe with 6% PET fibers obtained the best results, since it increased the compressive strength of the adobe by 19%, reduced the absorption percentage by 12% and finally reduced the density by 16.4%. Therefore, the addition of PET fibers in adobe is recommended, as it contributes to improve its mechanical and physical properties. Additionally, it reduces pollution in streets, rivers, parks, etc. because it promotes the recycling of PET bottles.
2

Estudo de concretos de diferentes resist?ncias ? compress?o submetidos a altas temperaturas sem e com incorpora??o de fibras de politereftalato de etileno (PET) / Study of different resistance of concrete when applied to high temperatures no and with addition fiber polyethylene terephthalate (PET)

Silva, Janaina Salustio da 22 April 2013 (has links)
Made available in DSpace on 2014-12-17T14:48:14Z (GMT). No. of bitstreams: 1 JanainaSS_DISSERT.pdf: 4645317 bytes, checksum: 1f500f6eaf05e8ac34d38ba500240ab2 (MD5) Previous issue date: 2013-04-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The reinforced concrete structures are largely used in buildings worldwide. Upon the occurrence of fire in buildings, there is a consensus among researchers that the concrete has a high resistance to fire, due mainly to its low thermal conductivity. However, this does not mean that this material is not affected by exposure to high temperatures. Reduction of the compressive strength, modulus of elasticity, discoloration and cracking, are some of the effects caused by thermal exposure. In the case of concretes with higher resistance occurs even desplacamentos explosives, exposing the reinforcement to fire and contributing to reducing the support capacity of the structural element. Considering the above, this study aims to examine how the compressive strength and porosity of concrete are affected when subjected to high temperatures. Were evaluated concrete of different resistances, and even was the verified if addition fibers of polyethylene terephthalate (PET) in concrete can be used as an alternative to preventing spalling. The results indicated that explosive spalling affect not only high strength concrete whose values of this study ranged from 70 to 88 MPa, as well as conventional concrete of medium strength (52 MPa) and the temperature range to which the concrete begins to suffer significant changes in their resistance is between 400 ? C and 600 ? C, showing to 600 ? C a porosity up to 188% greater than the room temperature / As estruturas de concreto armado s?o largamente utilizadas nas edifica??es em todo o mundo. Quando da ocorr?ncia de inc?ndio em edifica??es, ? consenso entre os estudiosos, que o concreto apresenta uma elevada resist?ncia ao fogo, devido principalmente a sua baixa condutividade t?rmica. No entanto, isto n?o significa que esse material n?o seja afetado pela exposi??o a elevadas temperaturas. Redu??o de resist?ncia ? compress?o e no m?dulo de elasticidade, altera??o na colora??o e aparecimento de fissuras, s?o alguns dos efeitos causados pela exposi??o t?rmica. No caso de concretos com resist?ncia mais elevada, ocorre ainda desplacamentos explosivos, expondo as armaduras ao fogo, e contribuindo assim para a redu??o da capacidade suporte do elemento estrutural. Diante do exposto, o presente trabalho tem por objetivo analisar como a resist?ncia ? compress?o e a porosidade do concreto s?o afetadas quando submetido a elevadas temperaturas. Foram avaliados concretos de diferentes resist?ncias, e ainda foi verificado se a incorpora??o de fibras de politereftalato de etileno (PET), em matriz de concreto, pode ser usada como alternativa a preven??o do lascamento. Os resultados indicaram que lascamentos explosivos acometem n?o somente os concretos de alta resist?ncia, cujos valores desta pesquisa variaram de 70 a 88 MPa, como tamb?m o concreto convencional de m?dia resist?ncia (52 MPa), e que a faixa de temperatura para o qual o concreto come?a a sofrer altera??es expressivas em sua resist?ncia fica entre 400 ?C e 600 ?C, apresentando aos 600 ?C uma porosidade at? 188% maior que a apresentada a temperatura ambiente
3

Adición de Fibras PET en el adobe para aumentar la capacidad resistente a la compresión, reducir: la densidad, el porcentaje de absorción de agua y la conductividad térmica en las viviendas de la zona rural de Ayacucho-Perú / Addition of PET fibers in adobe to increase the compressive strength, reduce: density, water absorption percentage and thermal conductivity in houses in the rural area of Ayacucho-Peru

Noa Huaman, Melisa Evelyn, Ordoñez Claros, Denys David 01 February 2022 (has links)
En la comunidad de Rancha (Ayacucho), se observa un gran porcentaje de viviendas de adobe, elemento que es altamente usado debido a su bajo costo. Sin embargo, este material presenta variaciones en relación a su capacidad resistente e insuficiente aislamiento térmico, esto último se ve más afectado debido a las bajas temperatura de la zona. Además, la densidad y porcentaje de absorción no son las mismas para todos los adobes, ya que los materiales empleados difieren debido a la zona, clima, etc. La propuesta de solución es añadir fibras PET al adobe. Por ello, este trabajo tiene como objetivo, determinar el efecto de las fibras PET en la resistencia a la compresión, densidad, porcentaje de absorción y conductividad térmica del adobe. El procedimiento consiste en elaborar muestras de adobe patrón y de adobe con fibras PET (2%,4%,6%), las cuales se someterán a ensayos basados en la norma E.080 (adobe) y E.070 (albañilería). Después de realizar todos los ensayos, se determinó que el porcentaje óptimo de fibras PET es el 6%, puesto que su resistencia a la compresión en unidades aumentó en 19% y en muretes un 62%. Por otro lado, la densidad se redujo en 16.4%, el porcentaje de absorción en 12% y la conductividad térmica en 35%. Por esta razón, es que la propuesta contribuye al reciclaje de botellas PET, al progreso de las propiedades mecánicas y físicas del adobe para que su tiempo de vida se prolongue y a mejorar el confort térmico dentro de las viviendas. / In the community of Rancha (Ayacucho), there is a high percentage of adobe housing, which is widely used due to its low cost. However, this material presents variations in relation to its resistant capacity and insufficient thermal insulation, the latter being more affected due to the low temperatures of the area. In addition, the density and absorption percentage are not the same for all adobe bricks, since the materials used differ due to the area, climate, etc. The proposed solution is to add PET fibers to the adobe. Therefore, the objective of this work is to determine the effect of PET fibers on the compressive strength, density, absorption percentage and thermal conductivity of adobe. The procedure consists of preparing samples of standard adobe and adobe with PET fibers (2%, 4%, 6%), which will be tested based on the E.080 (adobe) and E.070 (masonry) standards. After performing all the tests, it was determined that the optimum percentage of PET fibers is 6%, since its compressive strength in units increased by 19% and in masonry by 62%. On the other hand, the density was reduced by 16.4%, the absorption percentage by 12% and the thermal conductivity by 35%. For this reason, the proposal contributes to the recycling of PET bottles, to the improvement of the mechanical and physical properties of adobe to extend its life span and to improve thermal comfort inside homes. / Tesis

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