El elevado costo de los dispositivos antisísmicos en la actualidad, hace prácticamente imposible su uso en edificaciones de viviendas de comunidades de escasos recursos económicos, dejándolas expuestas a los acontecimientos sísmicos. Por dicho motivo, se tiene como objetivo el desarrollo de un sistema de aislamiento sísmico de bajo costo, elaborado con materiales económicos y accesibles. En la etapa inicial se desarrolló un modelo matemático, analizando su estabilidad mediante retratos de fase y el principio mínimo de energía potencial. A continuación, se analizó la influencia de parámetros geométricos en la respuesta dinámica del sistema. Con la implementación numérica del modelo, se analizó la respuesta estructural del sistema cuando es sometido a sismos con contenidos de frecuencias distintos, obteniendo como resultado una reducción de aceleraciones totales que varían entre un rango de 4.5 veces. El sistema se validó a través de la adquisición de las propiedades dinámicas con sismógrafos, de un modelo experimental expuesto a microtrepidaciones; y su comparación con los resultados obtenidos del modelo matemático. El sistema de aislamiento propuesto no solo reduce las aceleraciones bajo los sismos propuestos, sino que también posee la característica principal de un sistema de aislamiento sísmico: Elongación de periodos.

Biomorphic SiC/Si compounds were fabricated from copaiba wood (Copaifera officinalis, natural wood native to Peru), by reactive infiltration of molten silicon in a porous carbon preform obtained by a controlled pyrolysis process of wood. Structural and microstructural characterization tests by X-ray diffraction and scanning electron microscopy, respectively, revealed, on the one hand, the presence of crystalline phases of SiC, Si and C, and on the other, the typical morphology of this type of material, which it consists of a continuous SiC scaffold with elongated channels in the direction of tree growth and the presence of residual Si and C located mainly in the porosities of the material. The mechanical behavior in uniaxial compression was also studied at a constant compression rate of 0.05 mm/min and as a function of temperature (from ambient to 1400 ºC) and test atmosphere (ambient air, humid air, dry air, Ar, N2 and reducing mixture (95% Ar + 5% H2). The mechanical results were evaluated based on values of maximum stress and modulus of elasticity (stiffness), finding a clear reduction in the values of maximum stress and stiffness of the material when the samples passed of ambient test temperatures at 1400 ºC. On the other hand, mechanical tests in a controlled atmosphere were carried out at a constant temperature of 1100 ºC and the results showed that the mechanical behavior of the studied compounds is slightly influenced by the working atmosphere. Mechanical data found in the various test conditions will be an important support for the definition of the maximum allowable stress (considering the safety factor applied for a particular case) in the industrial application of the materials studied in this work.

This work presents the results of the thermomechanical evaluation of geopolymeric concrete fabricated from mining tailings, rice husk ash and fine sand. Ten types of geopolymeric concrete were studied and the relationship between the initial volumetric concentrations of the components in the mixtures and the maximum resistance in uniaxial compression under conditions of variable temperature (between ambient and 600 °C) was analyzed. The results revealed that increases in the concentration of mining tailings and fine sand lead to an increase in the value of the maximum mechanical resistance, in contrast, the increase in the concentration of rice husk ash led to a reduction in the value of the maximum mechanical resistance. Furthermore, increases in test temperature, up to 500 °C, led to systematic increases in maximum mechanical strength. Finally, the geopolymeric concretes presented a brittle-ductile transition between 500 and 600 °C showing only a ductile behavior when tested at 600 °C and only brittle up to test temperatures of 500 °C.

Reinforced geopolymeric mortars were obtained by mixing mine tailing, fine sand, alpaca wool fibers ( in variable amounts) sodium hydroxide and potable water, it was possible to verify the effect of the addition of alpaca wool on the mechanical behavior in uniaxial compression of the mortars studied. The mechanical data found revealed a systematic decrease in the maximum stress as the volume of wool added in the mortar mixtures manufactured increased. On the other hand, a higher degree of deformation was verified in mixtures with a greater volume of added fibers, reaching deformation values of up to 5%. The maximum strength values were in the range of 4 to 21 MPa for samples with 8 and 0 Vol. % of added fibers, respectively. Among the microstructural characteristics of the mortars studied, a continuous binder phase corresponding to the geopolymer could be appreciated, with sand particles and wool fibers dispersed within the binder phase. The real density and average porosity of the reinforced mortars were 2.65 g/cm3 and 32%, respectively.

The traditional method of manufacturing SiC compounds is associated with a serious environmental problem, mainly due to the need for large amounts of energy (generally derived from oil) to reach processing temperatures (typically above 2500 ºC). In addition, the chemical reaction that gives rise to the formation of SiC has CO and CO2 as by-products. Therefore, in this work an alternative method to manufacture SiC/Si composites using waste from the wood industry as the main raw material was developed. SiC/Si composites were fabricated by infiltration of molten silicon into carbon preforms at 1500 °C. The carbon preforms were obtained by pyrolysis (in an inert Ar atmosphere) of four types of resin-carbon mixtures. The carbon used in the mixtures was obtained by pyrolysis of sawdust powder. The mechanical and thermomechanical behavior in uniaxial compression was studied at a constant compression rate of 0.05 mm/min at different temperatures (ambient, 1100 °C and 1400 °C). The maximum resistance values found were in the range of 58 and 384 MPa, while the Young's modulus values were between 40 and 120 GPa. The porosity found in the materials was between 1 and 4%. Finally, the fabricated compounds presented a homogeneous microstructure of interconnected silicon carbide in gray contrast and dispersed and unconnected whitish phases of uniformly distributed silicon.

Geopolymeric mortars with volumetric fractions of 0.6:1:0.3 for a binder powder, fine sand and sodium hydroxide solution (12M), respectively; have been fabricated by mixing the solid materials and the subsequent addition of sodium hydroxide solution 12M to form a workable paste, to later be cured for 28 days at room temperature. The microstructures of the fabricated materials reveal the existence of two phases with notable difference, one continuous to the geopolymer binder phase and another discontinuous of fine sand particles agglutinated by the binder phase. Mechanical compression tests are performed at a constant compression rate of 0.05 mm/min and at temperatures ranged from room temperature to 500°C. The mechanical results are ranged from 19 and 69 MPa for all the materials studied. On the other hand, there was an increase in mechanical resistance up to test temperatures of 200°C and the progressive reduction of resistance at temperatures above 200°C, with a fragile-ductile transition zone between 400 and 500°C and completely ductile behavior from test temperatures of 500°C.