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Mejora de las propiedades mecánicas de los bloques de tierra comprimida (BTC) reforzados con cemento y fibra naturalCabrera Vargas, Marlo Manuel, Tello Ormeño, Jose Daniel 11 January 2021 (has links)
Existe en la actualidad una intensa búsqueda constante de recursos y tecnologías menos contaminantes, que consumen menos energía en la construcción. El bloque de tierra comprimida (BTC) reforzado con fibra natural puede ser una alternativa efectiva. Este estudio presenta los resultados de una investigación para establecer las propiedades mecánicas del BTC estabilizado con cemento y reforzado con fibra de bagazo de caña. Se consideró evaluar las siguientes combinaciones BTC, BTCE (6% de cemento), BTCB-I (4% de cemento y 0.5% de fibra) y BTC-II (4% de cemento y 1% de fibra). Además, los resultados de las pruebas mecánicas se compararon con normas establecidas y con otras investigaciones relacionadas al tema.
Se observó que, con el aumento de cemento, la resistencia de los bloques de tierra comienza a incrementarse gradualmente. Sin embargo, se puede reducir la cantidad de cemento reemplazándola con un mínimo de 0.5% de fibra natural en estado seco, representando bajas pérdidas de resistencia. De la investigación se sugieren analizar coeficientes de diseño a diferentes condiciones, considerando que con un mínimo de 4% de cemento y un 0.5-1% de fibra fue suficiente para producir BTC que cumplan con los requisitos estipulados en la norma peruana. / There is currently an intense constant search for less polluting resources and technologies, which consume less energy in construction. Natural fiber reinforced compressed earth block (BTC) can be an effective alternative. This study presents the results of an investigation to establish the mechanical properties of BTC stabilized with cement and reinforced with cane bagasse fiber. It was considered to evaluate the following combinations BTC, BTCE (6% cement), BTC-I (4% cement and 0.5% fiber) and BTC-II (4% cement and 1% fiber). In addition, the results of the mechanical tests were compared with established norms and with other research related to the subject.
It was observed that, with the increase of cement, the strength of the earth blocks begins to increase gradually. But nevertheless, the amount of cement can be reduced by replacing it with a minimum of 0.5% natural fiber in the dry state, representing low resistance losses. From the reach it is suggested to analyze design coefficients at different conditions, considering that a minimum of 4% cement and 0.5-1% fiber was enough to produce BTC that comply with the provisions of the Peruvian standard. / Trabajo de investigación
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Mechanical Evaluation of an Elastomeric Cushion For Total Knee Replacement / Mechanical Evaluation of an Elastomer Cushion For Total Knee ReplacementKelly, Brian 05 1900 (has links)
Mechanical factors have been cited as a primary cause of total knee replacement failure. A hypothesis has been formulated stating that the introduction of a compliant interface into a total knee prosthesis would moderate excessive stresses and strains, thereby, extending joint life. A biocompatable elastomer developed by the Dow Corning Corporation was selected for mechanical evaluation as a cushioning material. Force-strain, impact, and fatigue tests were conducted on several specially designed and fabricated elastomer test shapes. Test results demonstrate that a suitably stiff and dynamically responsive elastomer cushion can be designed to handle repeated physiological knee joint loads. Physiological impacts with cadaver tibias demonstrated significant shock reduction benefits, including peak force reductions of up to 70%, with the addition of different elastomer shapes. Compressive fatigue evaluation of elastomer samples was inconclusive owing to extensive sample wear. As a result configurations or applications where the elastomer can move relative to a rigid surface are not recommended. A new, mechanically contained elastomer shape was designed and tested which greatly reduced wear. Bonding of this new shape to prosthetic joint materials is recommended for further experimental evaluation. / Thesis / Master of Engineering (ME)
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