Development of iron ore tailings based wood-cement composite panels.

This article evaluated the effect of using mining waste on the mechanical, physical, thermal, and microstructural properties of cement-wood panels. The percentages of 10, 20, 30, and 40% were evaluated as replacing cement with mining waste. The wood particles of Pinus oocarpa were evaluated for their chemical, anatomical, and physical characteristics, and the mining waste was evaluated for its granulometry, chemical composition, and inhibition index. The composites were evaluated for their physical-mechanical properties, X-ray diffraction and infrared spectroscopy analysis, microstructural, thermal, and durability. All evaluated treatments met the requirements of the Bison standard for MOR and MOE for static bending and internal bonding, even after accelerated aging. It was possible to conclude that it is feasible to replace 40% of cement with mining waste for the production of cement-wood panels in industrial scale.

Pectin-based color indicator films incorporated with spray-dried Hibiscus extract microparticles.

Colorimetric films incorporated with anthocyanins as an indicator for freshness monitoring have aroused growing interest recently. The pH-sensing colorimetric film were developed based on pectin (HM), containing aqueous hibiscus extract microparticles (HAE). HAE microparticles were obtained by spray drying with different wall materials (Inulin -IN, maltodextrin- MD and their combination). The films were obtained on large scale by continuous casting. These films were characterized for physicochemical analysis, morphological structure, thermal and barrier properties, antioxidant activity, and color change at different pH. The addition of HAE microparticles caused relevant changes to HM-based films, such as in mechanical behavior and improved barrier property (11-22% WVTR reduction) depending on the type of wall material used and the concentration added. It was verified with the thermal stability of films, with a slight increase being observed. The color variation of smart films was entirely pH-dependent. Overall, the proposed color indicator films showed unique features and functionalities and could be used as an alternative natural pH indicator in smart packaging systems.

Physical, mechanical, and thermal properties of concrete roof tiles produced with vermiculite.

This study aimed to evaluate the effect of using expanded vermiculite and its impact on the production of concrete roof tiles. The control treatment and replacement of 12.5, 25, 37.5, and 50% sand by vermiculite were evaluated. The concrete roof tiles were moulded by the simultaneous pressing and extrusion mechanical process. The control trace was comprised by 21.95% CPV-ARI cement, 65.85% sand, and 12.20% limestone. After production, the concrete roof tiles were cured for 28 days. The physical (roof tiles classification, samples dry weight, water absorption, and porosity), mechanical (splitting tensile strength), and microstructural properties were evaluated. All treatments were assessed before and after accelerated ageing. The thermal properties of the modification in the concrete roof tiles' composition were also analysed. The evaluated amounts of vermiculite significantly affected the physical, mechanical, and thermal properties of concrete roof tiles. The use of vermiculite in concrete roof tiles reduced their dry weight and thermal conductivity, not impairing their durability. The use of 31.0% vermiculite in concrete roof tiles was suggested for better thermal insulation optimization (20.29% reduction) and weight reduction (7.92% and 7.94% at 28 days of curing and after accelerated ageing, respectively), along with adequate physical, mechanical, and durability properties.

Lignocellulosic materials as soil-cement brick reinforcement.

The need for environmental preservation requires civil engineering to reach new concepts and technical solutions aiming at the sustainability of its activities and products. In this context, this study aimed to evaluate the effect of using different types and percentages of vegetable particles on the physical, mechanical, and thermal properties of soil-cement bricks. Bamboo, rice husk, and coffee husk particles at 1.5 and 3% percentages and a control treatment not using the particle were evaluated. The chemical properties, shrinkage, compaction, consistency limits, and grain size were characterized for the soil; and the anatomical, chemical, and physical properties for the lignocellulosic particles. The bricks were produced using an automatic press and characterized after the curing process for density, water absorption, porosity, loss of mass by immersion, compressive strength, durability, and thermal conductivity. The increase in the lignocellulosic waste percentage caused a mechanical strength decrease and bricks' porosity and water absorption increase. However, it caused a decrease in density and an enhancement in loss of mass and thermal insulation properties. The bricks produced with rice husk obtained the best results in terms of mechanical and thermal properties, and were still among the best treatments for physical properties, standing out among the lignocellulosic waste as an alternative raw material source for soil-cement brick production.

Soil-Cement Bricks Development Using Polymeric Waste.

This research aimed to evaluate the effect of adding different polymeric waste percentages and types on the physical, mechanical, thermal, and durability properties of soil-cement bricks. Tire and polyethylene terephthalate (PET) waste were evaluated at 1.5 and 3.0% (mass/mass). The soil was characterized in terms of shrinkage, compaction, consistency limits, particle size, and chemical analyses, whereas the waste particles were submitted to morphological characterization. The bricks were produced in an automatic press with a 90:10 (mass/mass) soil:cement ratio. The soil-cement bricks were characterized by density, moisture, water absorption, loss of mass by immersion, compressive strength, thermal conductivity, and microstructural analysis. PET waste stood out for its use as reinforcement in soil-cement bricks. The best performance was obtained for bricks reinforced with 1.5% PET, which showed a significant compressive strength improvement, meeting the marketing standards criteria, even after the durability test, as well as obtaining the lowest thermal conductivity values. The percentage increase from 1.5 to 3.0% fostered a significant water absorption and loss of mass increase, as well as a significant compressive strength reduction of the bricks.

Study of the use of polymeric waste as reinforcement for extruded fiber-cement.

The disposal of post-consumption tires and plastics has become a significant environmental concern. New routes for recycling and using polymeric waste are needed since current treatment and disposal options do not reach the production of these materials. In this context, this study aimed to evaluate the effect of the use of tire and polyethylene terephthalate (PET) waste at different amounts on the physical, mechanical, thermal, and durability properties of extruded fiber-cement. Portland cement was replaced with 1, 2, 3, 4, and 5% by weight of polymeric waste from tire and PET. The fiber-cement was evaluated at 28 curing days and after accelerated aging, for density, water absorption, porosity, modulus of rupture, modulus of elasticity, proportionality limit, tenacity, and thermal conductivity properties. Tire and PET waste could be used as reinforcement material in fiber-cement, allowing for not only the correct destination and development of more sustainable new products but also the improvement of physical, mechanical, thermal, and durability properties of extruded fiber-cement.

Study of new reinforcing materials for cementitious panel production.

The development of building materials using new types of raw materials is currently on demand by society and the industry. It is intended to reduce production costs, improve properties and obtain ever-increasingly sustainable processes and products. In this respect, this work aimed to evaluate the effect of new types of reinforcement material on the physical-mechanical and thermal properties of cement-based panels. Cement-based panels reinforced with pine wood, coffee husk waste, rice husk and polyethylene terephthalate (PET) were evaluated. The panels were produced with 1.30 g.cm-3nominal density; 1:2.5 reinforcement material: cement ratio; 1:1.5 water:cement ratio; 0.25 cement hydration rate using Portland ARI V cement and 3% calcium chloride (CaCl2) as additive. The panels' physical, mechanical and thermal properties were evaluated before and after accelerated aging. PET bottle wastes showed great potential for use in cement-based panel production, obtaining the best physical and mechanical results, and showing superior performance to pine wood panels. Cement-based panels reinforced with coffee husk and rice husk waste obtained lower physical-mechanical performance, presenting usage limitations, however, with the lowest values of thermal conductivity.

Influence of particle size on the physico-mechanical and energy properties of briquettes produced with coffee husks.

Briquetting is a technology with the potential to convert agricultural wastes into solid biofuels with improved handling, transport, storage, and energy efficiency characteristics. It is important to study the variables related to the briquetting process and the raw material because these parameters can affect the quality of the final product. Thus, the objective of this study was to investigate the influence of particle size on the physico-mechanical and energy properties of briquettes produced with coffee husks. Three particle size fractions were obtained: particles larger than 1.8 mm, in the range of 1.8-1.2 mm, and smaller than 1.2 mm. The coffee husk briquettes were prepared in a densification system at 120 °C and 15 MPa for 15 min. The physical, mechanical, and energy characteristics such as apparent density, volumetric expansion, compressive strength, abrasion resistance, and energy density were determined. A combustibility test was also carried out. The results showed that particle size influenced the apparent density, compressive strength, and energy density of the briquettes. However, there was no significant difference in the volumetric expansion or abrasion resistance of the densified products among the treatments. In general, the briquettes made with particles smaller than 1.2 mm had better physico-mechanical and energy characteristics.

Eucalyptus wood and coffee parchment for particleboard production: Physical and mechanical properties / Madeira de eucalipto e pergaminho de café na produção de aglomerados: Propriedades físicas e mecânicas

ABSTRACT The wood panel industry is constantly growing, being necessary the innovation in technologies and raw materials to improve the quality of the final product. Considering the shortage and pressure to decrease the dependence of wood, there is an interest in other renewable materials such as agricultural wastes. Among these wastes, coffee parchment is one which deserves notoriety. An alternative use for coffee parchment could be for production of particleboard in association with wood particles. This study aimed to evaluate the feasibility of using coffee parchment for production of particleboard. The following percentages of wastes were used: 0, 10, 20, 30, 40 and 50% in association to eucalyptus wood. The panels were produced with 8% of urea formaldehyde (based on dry weight of particles). The pressing cycle consisted by: pre-pressing of 0.5 MPa for 10 minutes followed by pressing of 4.0 MPa, and temperature of 160° C for 15 minutes. The compaction ratio of particleboards produced using higher quantities of parchment improved the physical properties. The properties of Water Absorption (2 and 24 h) and Thickness Swelling (2 h) decreased with increasing percentage of coffee parchment. The Thickness Swelling (24 h) showed not significant effect with an increase of coffee waste. The Modulus of Elasticity for coffee parchment particleboards was in the range 646.49 ± 112.65 to 402.03 ± 66.24 MPa, while the Modulus of Rupture ranged from 8.18 ± 1.39 to 4.45 ± 0.75 MPa. The results showed that 10% of coffee parchment could be added for production of particleboards.

RESUMO A indústria de painéis de madeira vem em constante crescimento, sendo necessária a inovação em tecnologias e matéria-prima para melhorar a qualidade do produto final. Considerando a escassez e pressão na diminuição da dependência por madeira, existe um interesse em outros materiais renováveis, como os resíduos agrícolas. Entre esses resíduos, o pergaminho de café merece destaque. Uma alternativa para utilização do pergaminho de café poderia ser na produção de particulados, em associação com partículas de madeira. O objetivo deste trabalho foi avaliar a viabilidade de utilização do pergaminho de café para produção de aglomerados. As porcentagens de resíduo utilizadas foram: 0, 10, 20, 30, 40 e 50% em associação com madeira de eucalipto. Os painéis foram produzidos com 8% de uréia-formaldeído (base massa seca de partículas). O ciclo de prensagem consistiu de: pré-prensagem de 0,5 MPa por 10 minutos, seguido por prensagem de 4,0 MPa e temperatura de 160° C por 15 minutos. A razão de compactação dos painéis produzidos com maiores quantidades de pergaminho melhorou as propriedades físicas. As propriedades de absorção de água (2 e 24 h) e inchamento em espessura (2 h) diminuíram com o aumento da porcentagem de pergaminho de café. O inchamento em espessura (24 h) não apresentou diferenças significativas com o aumento de resíduo de café. O Módulo de Elasticidade dos painéis variou de 646,49 ± 112,65 até 402,03 ± 66,24 MPa, enquanto o Módulo de Ruptura variou de 8,18 ± 1,39 até 4,45 ± 0,75 MPa. Os resultados mostraram que até 10% de pergaminho de café poderia ser adicionados para a produção de painéis aglomerados.

Efeito da incorporação de casca de café nas propriedades físico-mecânicas de painéis aglomerados de Eucalyptus urophylla S. T. Blake / Effect of the incorporation of coffee husks on the physico-mechanical properties of Eucalyptus urophylla S. T. Blake particleboards

Neste trabalho objetivou-se avaliar a influência da incorporação de casca de café nas propriedades físico-mecânicas de painéis aglomerados produzidos com Eucalyptus urophylla S.T. Blake. Os painéis foram produzidos com incorporação de 25, 50 e 75 por cento de casca de café, em três teores da resina fenol-formaldeído (6, 9 e 12 por cento) e 1 por cento de parafina. A densidade nominal dos painéis foi de 0,7 g/cm³ e o ciclo de prensagem compreendeu uma pressão de 3,92 MPa e temperatura de 180ºC por 8 minutos. Pelos resultados obtidos foi possível observar que: as propriedades físicas dos painéis aglomerados apresentam relação linear decrescente com o aumento do teor de resina, e crescente com a porcentagem de casca de café, apresentando maiores valores de absorção de água e inchamento em espessura. As propriedades mecânicas apresentam relação linear crescente com o aumento do teor de resina, e decrescente com a porcentagem de associação de casca de café. Do modo que a pesquisa foi conduzida, a incorporação da casca de café prejudica a qualidade dos painéis produzidos.

The objective of this study was to evaluate the influence of the incorporation of Coffee husks in the production of particleboard with Eucalyptus urophylla S.T. Blake. The panels were produced incorporating 25 percent, 50 percent, and 75 percent of Coffee husks at three levels of resin phenol-formaldehyde (6, 9 and 12 percent) and 1 percent of paraffin. The nominal density of the panels was 0.7 g/cm³ and the cycle of pressing consisted in a pressure of 3.92 MPa under a temperature of 180°C for 8 minutes. By the results it was possible to observe that the physical properties of the particleboard have a linear relationship decreasing with the increase in the level of resin, and increasing with the increase in the percentage of coffee husks, showing higher values of water absorption and thickness swelling. The mechanical properties show a linear relationship growing with the increase of resin level, and decreasing with a reduction the percentage of coffee husk association. The way that the search was conducted, the incorporation of the Coffee husks harms the quality of the panels produced.