Abstract: The present research is focused on synthesizing and physically characterization different mixtures of concrete mortar reinforced with thermostable polymers from industrial waste. The mortars were made from the homogeneous mixture of cement, gravel, and water with additions of polyepoxide in different percentages. This polymer carried a milling process to obtain particle sizes of 1, 2 and 3mm. The mixtures were emptied in cubic bronze molds (5cm side) without vibrating compaction and allowed to stand for 24 hours before being removed. Ten mortars were prepared by mixture and they were cured in water for 28 days at room temperature before being characterized. Subsequently, the weight, compression strength and thermal conductivity of the samples were measured. The best results were for the mortars with additions of 100% polyepoxide (without gravel) and 3mm particle size, with a compression strength of 76.6kgcm-2 (higher than that required in mortars, 70kgcm-2), a thermal conductivity of 0.68Wm-1K-1 (59.93% less than conventional mortar, 1.70Wm-1K-1) and a weight of 141g (33.80% lower than the traditional mortar, 213g). According to the results obtained, a reliable alternative is presented to reuse waste material in the construction industry, replacing gravel by polyepoxide polymer particles in the process of manufacturing masonry elements providing the final product with the characteristics of lightness, thermal insulation, and acceptable compression strength, through simple, economical and sustainable processes.

Resumen: La presente investigación se centra en la síntesis y caracterización física de diferentes mezclas de mortero de hormigón reforzado con polímeros termoestables de residuos industriales. Los morteros se hicieron a partir de la mezcla homogénea de cemento, grava y agua con adiciones de poliepóxido en diferentes porcentajes. Este polímero llevó un proceso de molienda para obtener tamaños de partículas de 1, 2 y 3mm. Las mezclas se vaciaron en moldes cúbicos de bronce (5cm de lado) sin compactación vibrante y se dejaron reposar durante 24 horas antes de ser retiradas. Se prepararon 10 morteros por mezcla y se curaron en agua durante 28 días a temperatura ambiente antes de ser caracterizados. Posteriormente, se midió el peso, la resistencia a la compresión y la conductividad térmica de las muestras. Los mejores resultados fueron para los morteros con adiciones de 100% de poliepóxido (sin grava) y 3mm de tamaño de partícula, con una resistencia a la compresión de 76.6kgcm-2 (mayor que la requerida en morteros, 70kgcm-2), una conductividad térmica de 0.68Wm-1K-1 (59.93% menos que el mortero convencional, 1.70Wm-1K-1) y un peso de 141g (33.80% menos que el mortero tradicional, 213g). De acuerdo con los resultados obtenidos, se presenta una alternativa sólida para reutilizar material de desecho en la industria de la construcción, reemplazando la grava por partículas de polímero poliepóxido en el proceso de fabricación de elementos de mampostería proporcionando al producto final las características de ligereza, aislamiento térmico y resistencia a la compresión aceptable, a través de procesos simples, económicos y sostenibles.

The sulphoaluminate of strontium, Sr4Al6O12SO4, was synthesized by solid state reaction from mixture of SrCO3, Al2O3 and SrSO4 (3:3:1 molar ratio) as pellets. The kinetics of formation has been studied in the range of temperature between 850ºC and 1100ºC using quantitative X-ray powder diffraction data (XRD) analysis. Likewise, at room temperature, the crystal structure was determined from conventional X-ray powder diffraction data using direct methods and it was refined by the Rietveld method. The kinetics mechanisms that showed the best fit, were identified as geometrical contraction at grain boundary (R1.1) and nucleation and growing by energy law (P1.1). The activation energy values obtained were 145.47KJmol-1 (R1.1) and 151.35KJmol-1 (P1.1), respectively. The resulting crystal structure was orthorhombic type (a: 13.32802Å, b: 13.34430Å and c: 9.38704Å). The observed adjustment parameters were RB: 0.0985, Rwp: 0.137, Rp: 0.0925 and Chi2: 1.94.

The synthesis of alumina (Al2O3)-composites having different amount of very fine titanium and titanium carbide reinforcement-particles has been explored. Two experimental steps have been set for the synthesis; the first step consisted of the pressureless-sintering of Al2O3-titanium powders which were thoroughly mixed under high energy ball-milling and through the second step it was induced the formation of titanium carbide during different times at 500 ºC by the cementation packing process. SEM and EDS analysis of the microstructures obtained in both sintered and cemented bodies were performed in order to know the effect of the activated carbon used as cementing agent on the titanium for each studied composite. It was observed that a titanium carbide layer growth from the surface into the bulk and reaches different depth as the titanium content in the composites increases. On the other hand, the use of ductile titanium notably enhanced density level and fracture toughness of the composites.

In this work a review is made about the different factors that affect the wettability of liquid metal-ceramic systems, making special emphasis in the Al-Al2O3 system. It is suggested a chemical modification of the interface liquid Al-Al2O3 through the use of elements known as lanthanides, which have strong affinity to oxygen. Lanthanides form a thin oxide film at the interface, diminishing in this way its surface energy, so wettability and therefore union between metal and ceramic is improved.

Se hace una revisión de los factores que influyen sobre la mojabilidad de sistemas metal líquido-cerámico, haciendo principal énfasis en el sistema Al-Al2O3. Se sugiere una modificación química de la interfase Al líquido-Al2O3 a través del uso de elementos conocidos como lantánidos, los que son fuertemente afines al oxígeno. Estos elementos forman una película delgada de óxido en la interfase disminuyendo así la energía superficial en la misma con lo cual se mejora la mojabilidad y por lo tanto la unión entre el metal y el cerámico.