Reuse of the industrial solid waste, consisting for foundry sands, in the confection of massive bricks and decorative pieces

O presente trabalho é resultado de pesquisa que investigou a viabilidade técnica da reutilização do resíduo sólido gerado pelas areias de fundição aglomeradas com argila, para aplicação no setor da construção civil e em peças decorativas. Para isso, a investigação estabeleceu uma metodologia, a qual avaliou a estabilização do resíduo em matrizes solidificadas de cimento Portland, melhoradas através da adição de sílica ativa e/ou aditivo superplastificante. Duas composições foram utilizadas na fabricação de tijolos maciços e na confecção de peças decorativas. Os resultados obtidos comprovam a viabilidade técnica para aplicação dos tijolos na execução de alvenarias e para a fabricação de peças decorativas, as quais apresentaram excelente valor agregado e potencial de comercialização.El trabajo, ora presentado, es resultado de investigación que estudió la factibilidad técnica para la reutilización del residuo sólido generado por las arenas de fundición hechas con arcilla, en el sector de la construcción y en piezas decorativas. Para eso, la investigación estableció una metodología que evaluó la estabilización del residuo en matrices solidificadas de cemento Portland, mejoradas por medio de adición de sílica activa y/o aditivo reductor de agua. Dos composiciones fueron utilizadas en la fabricación de ladrillos macizos y en la confección de piezas decorativas. Los resultados obtenidos confirman la factibilidad técnica para la aplicación de los ladrillos en la ejecución de mamposterías y para la fabricación de piezas decorativas, las cuales presentaron excelente valor agregado y óptimo potencial de comercialización.The present work is a result of a research that investigated the technical viability for the reuse of the solid waste generated by foundry sands agglomerated with clay, for application in the sector of the civil construction and in decorative pieces. For that, the investigation established a methodology, which evaluated the stabilization of the waste in solidified matrices of Portland cement, improved with the addiction of silica fume and/or fluidificant additive. Two compositions had been used in the confection of massive bricks and decorative pieces. The obtained bricks had been submited to tests of compressive strength, water absorption and solubilization, The obtained results proved the technical viability for apply the briks in the execution of masonry and to produce decorative pieces, that which presenting excellent aggregated value and potencial to commercialize them

Absortância solar e desempenho térmico de tintas frias para uso no envelope construtivo

Materials with low absorptance and high emittance are known as cool materials. When used on the building envelope these materials decrease building surface temperatures, reducing energy demand in conditioned buildings and making more comfortable non conditioned buildings. In this work, cool and standard paints for exterior walls and roofs were comparatively evaluated through their absorptance and emittance properties, as well as the thermal performance evaluation with surface temperature measurements. Cool paints were selected from available products in the Brazilian and international market, as well as standard paints with the same color, totaling 15 samples. Results indicated that cool paints with low near-infrared absorption, but with the same color of standard ones have lower solar absorptance. Surface temperature measurements for samples exposed to the sun confirmed that coatings solar absorptance directly affects the thermal performance of painted surfaces, which corroborates that as lower is the surface solar absorptance, lower is the building envelope temperature. It was observed that the potential to use cool paints on buildings results from the decrease in the near-infrared solar absorptance, with the possibility to use paints with darker colors, but with better thermal performance when compared with standard paints with the same color.Materiais que apresentam baixas absortâncias e altas emissividades são conhecidos como materiais refletivos ou frios. Esses materiais, quando usados como revestimento no envelope construtivo permitem a redução de temperaturas superficiais nos edifícios, minimizando a necessidade de energia para refrigeração em edificações artificialmente condicionadas e tornando mais confortáveis edificações não condicionadas. Neste trabalho, tintas frias e convencionais para pintura externa de paredes e coberturas são avaliadas comparativamente através da caracterização de suas absortâncias e emissividades, assim como o desempenho térmico das mesmas a partir de medições de temperaturas superficiais. Foram selecionadas tintas frias para pintura de paredes e coberturas a partir de produtos disponíveis no mercado nacional e internacional, assim como tintas convencionais de cores correspondentes, totalizando 15 amostras. Os resultados indicaram que tintas frias com baixa absorção no infravermelho-próximo, porém de cor e tonalidade iguais às tintas convencionais, resultam em tintas com menores absortâncias solares. As temperaturas superficiais das amostras expostas ao sol evidenciaram que a absortância solar das tintas afeta diretamente o desempenho térmico das superfícies pintadas, comprovando que quanto mais baixa é a absortância solar da superfície, menor a temperatura do envelope construtivo. Observou-se que o grande potencial de uso das tintas frias em edificações é resultado da diminuição da absortância solar na região do infravermelho, com a possibilidade de se utilizar cores de tonalidade mais escura, porém com melhor desempenho térmico quando comparadas com tintas convencionais de cor e tonalidade semelhante

Thermogravimetric analyses and mineralogical study of polymer modified mortar with silica fume

Mineral and organic additions are often used in mortars to improve their properties. Microstructural investigation concerning the effects of styrene acrylic polymer and silica fume on the mineralogical composition of high-early-strength portland cement pastes after 28 days of hydration are presented in this paper. Thermogravimetry and derivative thermogravimetry were used to study the interaction between polymers and cement, as well as the extent of pozzolanic reaction of the mortars with silica fume. Differential scanning calorimetry and X ray diffraction were used to investigate the cement hydration and the effect of the additions. The results showed that the addition of silica fume and polymer reduces the portlandite formation due to delaying of Portland cement hydration and pozzolanic reaction

Sostenibilidad en la arquitectura y el estudio de los compuestos orgánicos volátiles emitidos por los pisos de vinilo en edificios residenciales

This paper is the result of PhD research in which has been studied about volatile organic compounds (VOCs) released in the indoor air of residential buildings by vinyl coatings, applied on floors within these environments. For this, it was adopted a method in which vinyl flooring samples were analyzed in a gas chromatography/ mass spectrometry in a chemical lab. The results showed us the kinds of VOCs that can be released indoor air by these products. Thus it was analyzed what damage that these chemicals can cause to human health if they are concentrated in large proportions.O presente trabalho é resultado de pesquisa que investigou sobre as emissões de compostos orgânicos voláteis (COVs) por revestimentos vinílicos, aplicados em pisos, no ambiente interno de residências. Para isso, adotou-se uma metodologia, na qual foram analisadas amostras destes revestimentos por cromatografia a gás acoplada a espectrometria de massas. Os resultados obtidos mostraram COVs que podem ser liberados no ar como ésteres, éter glicólicos, alcanos, alcenos, alcoóis, cetonas e antioxidantes, os quais podem causar sintomas como irritações de pele, garganta e dificultar a respiração. Por fim, foram analisados os limites máximos de exposição à estas substâncias, segundo normas internacionais.Este artículo es el resultado de una investigación en el que se ha estudiado los compuestos orgánicos volátiles liberado en el aire por los revestimientos de vinilo aplicados en los pisos interiores de edificios residenciales. Hemos adoptado un método en el que se analizaron muestras de vinilo por una cromatografía de gases / espectrometría de masas en un laboratorio de química. Los resultados revelaron cuáles las clases de COVs son liberados en el aire interior, y los riesgos que puedan ofrecer a la salud humana, si ellos se concentran en grandes proporciones

Article ID 219143

Overpopulation of urban areas results from constant migrations that cause disordered urban growth, constituting clusters defined as sets of people or activities concentrated in relatively small physical spaces that often involve precarious conditions. Aim. Using residential grouping, the aim was to identify possible clusters of individuals in São José do Rio Preto, Sao Paulo, Brazil, who have or have had leprosy. Methods. A population-based, descriptive, ecological study using the MapInfo and CrimeStat techniques, geoprocessing, and space-time analysis evaluated the location of 425 people treated for leprosy between 1998 and 2010. Clusters were defined as concentrations of at least 8 people with leprosy; a distance of up to 300 meters between residences was adopted. Additionally, the year of starting treatment and the clinical forms of the disease were analyzed. Results. Ninety-eight (23.1%) of 425 geocoded cases were located within one of ten clusters identified in this study, and 129 cases (30.3%) were in the region of a second-order cluster, an area considered of high risk for the disease. Conclusion. This study identified ten clusters of leprosy cases in the city and identified an area of high risk for the appearance of new cases of the disease

Study of the adherence between polymer-modified mortars and porcelain stoneware tiles

Despite the excellent characteristics of porcelain tiles, their application on building facades requires special attention, since this material differs from conventional ceramics and because facades are exposed to weathering that can damage ceramic revetments. The combination of polymer and silica fume to produce mortars results in excellent properties, which are ideal for repairs and revetments requiring high performance. Such improvements justify its study for the installation of porcelain tiles. This article presents bond strength results for mortars containing different amounts of polymer and silica indicating the applicability of these mortars as a construction material. To complement this study, the interface between the porcelain and the mortars was analyzed by scanning electron microscopy (SEM)