In these last decades, with the advance of industrialization, the enormous quantity of residue that is discarded by the industry has been generating discussions about eco-efficient solutions. This research has the objective of developing an artificial stone with residue of quartzite and fine quarry gravel (granite), utilizing the vibro-compression vacuum method. The residue was separated in three granulometric ranges with sieving: Large and medium (fine quarry gravel) and fine (quartzite). A statistical treatment was used in the acquired data, utilizing analysis of variance (ANOVA). The characterization was through a physical, mechanical, dilatometric and microstructural analysis. The obtained results classify the material as having high potential to be used for flooring in the civil construction industry, since it has low porosity <0.17% e water absorption < 0.3%, maximum flexural strength > 30 MPa, being able to be utilized in medium and low traffic environments.

Novel civil construction materials based on waste can be an optimal alternative for waste management, reducing its improper disposal while engaging an otherwise discarded material as a raw material in other production processes. This research’s main objective was to develop and characterize two novel artificial stones based on waste glass from bottles and aggregated with epoxy resin (ASG-EP) and polyurethane resin (ASG-PU) from castor oil, respectively, as well as the comparison of the two developed materials. Plates were manufactured with 15% of epoxy or 15% polyurethane resins and 85% of waste glass from bottles. The mixture was molded with a process of 6Hz vibration, 600mmHg of vacuum, and hot compaction at 90ºC for EP and 80ºC for PU. Results evidenced that the development of ASGs based on waste glass from bottles is technically and economically viable.

The objective of this research was to produce artificial stone plates based on granite and mirror wastes and epoxy matrix, by vibration, compression, and vacuum and to characterize them. Plates were manufactured with 15%wt epoxy resin and 85% of aggregates in the proportion of 1/3 of granite waste from Ocre Itabira gray granite and 2/3 of mirror waste. The apparent density, water absorption, and apparent porosity values were 2.22 g/cm3, 0.11%, and 0.25%, respectively, the flexural strength was 34.36 MPa, abrasive wear after a 1000m track was 2.28mm and the breaking height in the impact resistance test was 0.45m. In addition, the stone was resistant to several staining agents. Therefore, the technical viability of the material developed was verified, with results compatible with studies already carried out in the area, making it possible to apply it as coatings and countertops in civil construction.

resumo: Os materiais álcali ativados (MAA) são definidos como materiais obtidos por intermédio da reação entre precursores e ativadores, e são separados em duas classes dependendo dos produtos formados na reação, os ricos em cálcio, como é o caso da escória de alto forno, cuja relação Ca/(Si+Al) é maior do que 1; e pobres em cálcio, que constitui a subclasse dos geopolímeros. Nesse artigo de revisão foram discutidos alguns aspectos bibliográficos a respeito da descoberta desses materiais, por meio de pesquisas realizadas por Victor Glukhovsky e por meio da caracterização de monumentos históricos por Davidovits, que se iniciaram nas décadas de 50 e 60 e persistem até os dias atuais. Também foram abordados os principais produtos obtidos na reação de ativação alcalina, utilizando a definição de polissialatos e zeólitas, no caso dos geopolímeros, e da estrutura da tobermorita, no caso dos materiais ricos em cálcio. As principais etapas da reação álcali ativadas, como dissolução, condensação, policondensação, cristalização e endurecimento, foram debatidas. Algumas técnicas para caracterização dos produtos da reação AA também foram examinadas, tais como difração de raios-X (DRX), espectrometria de ressonância magnética nuclear (RMN), espectroscopia no infravermelho com transformada de Fourier (FTIR) e microscopia eletrônica de varredura (MEV). Por fim, foram explorados os principais fatores que interferem na cinética das reações AA, onde destaca-se o tipo de cura e de solução ativadora utilizada na produção dos MAA.

abstract: The Alkali-Activated Materials (AAM) are defined as materials obtained through the reaction between precursors and activators, and are separated into two classes depending on the products formed in the reaction, those rich in calcium, as the blast furnace slag, whose Ca/(Si+Al) ratio is higher than 1; and poor in calcium, which is the geopolymers subclass. In this review article, some bibliographical aspects were discussed regarding the discovery of these materials, through research conducted by Victor Glukhovsky and through the characterization of historical monuments by Davidovits, which began in the 50s and 60s and persist to the present day. The main products obtained in the alkaline activation reaction were also addressed, using the definition of polysialates and zeolites, in the case of geopolymers, and the tobermorite structure, in the case of materials rich in calcium. The main steps of the alkali-activated reaction, such as dissolution, condensation, polycondensation, crystallization, and hardening, were discussed. Some techniques for characterizing the AA reaction products were also examined, such as X-ray diffraction (XRD), nuclear magnetic resonance spectrometry (NMR), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Finally, the main factors that interfere in the kinetics of AA reactions were explored, in which the type of cure and the activating solution used in the alkali-activated materials production stands out.

A comparative investigation on the firing behavior of a natural kaolinitic clay from Campos dos Goytacazes, Brazil, and its specific clay fraction was performed. The clay fraction, equivalent diameter less than 2 µm, was separated from the precursor clay by a sedimentation method. Chemical analysis, X-ray diffraction (XRD) and scanning electron microscopy were used to characterize the unfired materials. Thermoanalysis and dilatometry were applied to follow the structural transformations. The firing behavior was studied by water absorption and XRD of samples fired in the temperature range from 400 to 1100°C. Differences were found between the natural kaolinitic clay and its clay fraction. The absence of quartz and smaller particles of the clay fraction result in a comparatively lower temperature for structural consolidation associated with reduced open porosity. This can be attributed to solid state sintering alone, in contrast to a higher temperature liquid phase sintering needed for complete consolidation of the natural kaolinitic clay.

The clay samples endure the incorporation of industrial and urban wastes, which do not cause large variations in their properties if added in controlled quantities. Wastes can be classified as fuel, fluxing and property affecting wastes. The fuel wastes usually have a high amount of organic matter, that when heated cause exothermic reactions, releasing heat to the process. The fluxing wastes cause a reduction in the ceramic melting points. The main aim of this work was to study the behavior of ceramics incorporated with fuel wastes (Eichhornia crassipes dry biomass) and fluxing wastes (granite) as well as blends of both wastes. Different compositions were prepared with incorporation of different percentages of these wastes in the clay samples, conformed by uniaxial pressing and fired at 550, 650, 750, 850, 950 e 1050ºC. The technological properties tested were: dry apparent density, linear shrinkage, water absorption and flexural rupture strength. Results indicate that the high calorific value of the biomass waste represents a great possibility of saving energy for the firing process. Incorporations can be indicated as a possibility of correct destination for the investigated wastes.

Waste incorporation into clay ceramic is a worldwide accepted recycling procedure for environmentally friendly reuse of spent industrial materials. In the present work a clay ceramic from the city of Campos dos Goytacazes, Brazil, was, for the first time, investigated with different amounts, up to 10 wt%, of a solid waste generated from the “Sulfatreat” natural gas treatment process. Both the waste and the incorporated ceramic were characterized by X-ray fluorescence and X-ray diffraction as well as vibratory sieving, gas chromatography and sedimentation method. Ceramic samples were prepared by uniaxial pressing at 18 MPa and sintered at 850°C. Physical and mechanical properties of these ceramics such as linear shrinkage, apparent density, water absorption and flexural strength were evaluated. Microstructure of the incorporated ceramics was analyzed by optical microscopy. The results showed that, within the standard deviation, the linear shrinkage and apparent density of the clay ceramic were not affected by the waste incorporation. However, the water absorption is benefitted, by decreasing above 5 wt% incorporation, while the flexural strength is impaired for any incorporated amount. Porosity and larger waste particles observed in microstructure are proposed reasons for these advantages and shortcomings.

Ornamental stones, such as marble and granite, are worldwide used as pavement cover and lining parts in civil construction. Dwindling deposits and environmental pollution, due to extraction methods, have motivated the replacement of natural ornamental stones by synthetic ones. In particular, artificial ornamental stones are being developed with mineral wastes incorporated into polymeric matrix. In this work, granite particle waste, from a quarry, which supplies plates for building construction, was used in amounts of 85 and 90 wt % together with epoxy resin to fabricate novel artificial stones. Physical and mechanical characterization disclosed superior properties that allow these new developed artificial stones to be applied as pedestrian traffic pavements.

Sisal fibers are among the natural lignocellulosic ones with great impact resistance for potential use in polymer composites. This work evaluates the ballistic efficiency of the distinct individual components of a multilayered armor. These include the front ceramic, the back metallic sheet and the intermediate layer as either the conventional aramid fabric or a novel sisal fiber reinforced epoxy composite. Sisal fibers incorporated in epoxy resin plates with volume fraction of 30% were ballistic tested using the 7.62 caliber ammunition. The fibers were embedded under pressure in the epoxy resin matrix and cured at room temperature for 24 hours. The tested specimens were examined by scanning electron microscopy.

The present work is part of an innovation research project aiming to develop artificial stone from industrial wastes. In principle, the project goal is to fabricate artificial stones with improved characteristics to be used as plates for housing and road construction. In this work, the specific industrial residue was an electrostatically precipitated powder obtained from the initial sintering stage of an integrated steelmaking plant. Plates were produce by vacuum vibro-compression of epoxy resin mixed with 80 and 85 wt% of this specific residue. After curing, the plates were characterized for physical parameters and mechanical properties. The microstructural aspect of the finishing surface was analyzed for both novel artificial stones by scanning electron microscopy. The results indicated that the 80% residue incorporated artificial stone is superior to the 85% residue incorporated and markedly stronger than a commercial artificial stone, incorporated with granite residue, with comparable density and water absorption. These characteristics favor the technical substitution of the presently investigated artificial for the commercial stone. In particular, based on wear tests, the residue incorporated artificial stone would be restricted to application as pavement in medium traffic roads.

Esse trabalho teve por objetivo estudar a influência da temperatura de sinterização nas propriedades físicas, mecânicas e microestruturais de cerâmica vermelha incorporada com cinza de bagaço de cana de açúcar. Foram utilizadas como matérias-primas uma massa cerâmica industrial para fabricação de telhas e uma cinza de bagaço de cana de açúcar, gerada na calcinação do bagaço em caldeiras de uma indústria sucro-alcooleira. Ambas as matérias-primas são provenientes da região de Campos dos Goytacazes, norte do Estado do Rio de Janeiro. Foram feitas incorporações de 0, 10 e 20% de cinza com granulometria inferior a 44 mm (325 mesh) na massa industrial. Os corpos de prova foram preparados por prensagem uniaxial e sinterizados a temperaturas de 900, 1050 e 1200°C. As seguintes propriedades foram determinadas: retração diametral, absorção de água e resistência mecânica por compressão diametral. Para análise microestrutural da cerâmica com incorporação de cinza foram realizados, após a sinterização a 1050 e a 1200°C, ensaios de difração de raios-X e de microscopia eletrônica de varredura. Os resultados indicam que não houve uma mudança significativa nas propriedades físicas e mecânicas da cerâmica vermelha com incorporação de cinza. A cerâmica com incorporação de 20% de cinza, sinterizada a 1200°C, apresentou grande diferença na microestrutura em relação às outras composições estudadas, apresentando grande formação de fase líquida.

This work has for objective to evaluate the influence of the sintering temperature in the physical, mechanical and microstructural properties of incorporate red ceramic with sugar cane bagasse ash. As raw materials an industrial ceramic body for production of tiles and a sugar cane bagasse ash, generated during the burning of the bagasse in boilers of an alcohol industry were used. Both raw materials were obtained from the area of Campos dos Goytacazes, north of the State of Rio de Janeiro. Incorporations of 0, 10 and 20% of ash with inferior granulometry to 44 mm (325 mesh) were made in the industrial ceramic body. Specimens were prepared by uniaxial press-molding and sintered at 900, 1050 and 1200°C. The following properties were determined: diametrical shrinkage, water absorption and mechanical resistance for diametrical compression. Microstructural analysis of the ceramic incorporated with ash was accomplished, after sintering at 1050 e 1200°C, by X-ray diffraction and scanning electron microscopy. The results indicated that there was no significant change in the physical and mechanical properties of the red ceramic incorporated with ash. The ceramic with incorporation of 20% of ash, sintered at 1200°C, presented great difference in the microstructure in relation to the other studied compositions, due to a significant formation of liquid phase.