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- Caracterização físico-química de cascas de amêndoas e nozes para valorização em obras de terraPublication . Marchiori, Leonardo; Nouioua, Thamer; Morais, Maria Vitoria; Silva, Flora Cristina Meireles; Albuquerque, Antonio; Andrade Pais, Luís; Cavaleiro, VictorOs resíduos agroindustriais têm sido investigados para aplicações de engenharia devido à sua elevada produção e ausência de valorização adequada face aos requisitos legais e de políticas e metas de sustentabilidade. O estudo das caraterísticas das cascas de amêndoas (CA) e nozes (CN) têm suscitado interesse na comunidade científica para desenvolver materiais alternativos e inovadores, com design sustentável, em várias aplicações. Este trabalho tem como objetivo caracterizar e analisar as propriedades físico-químicas de CA, CN e de um solo residual, bem como de duas misturas de cada resíduo com o solo, com 10% e 40% de cascas, para eventual aplicação em obras de terra. Os resultados mostraram que ambos os resíduos poderiam ser incorporados no solo para torná-los mais granulares e reduzir a densidade específica, além de terem potencial para remover alguns poluentes da água devido à presença de aluminosilicatos com K2O, CaO e SiO2. Esta aplicabilidade poderia reduzir a utilização de solos naturais em obras de terra, a incineração de ambas as cascas e sua deposição em aterros sanitários, podendo promover a sua valorização e criar produtos baseados em resíduos no âmbito da economia circular. No entanto, são necessários estudos adicionais para uma melhor compreensão do seu potencial para utilização em obras de terra, nomeadamente ensaios de lixiviação, degradação e adsorção.
- Evaluation of the potential use of water treatment sludge (WTS) as a waterproofing material for waste containment earthworksPublication . Marchiori, Leonardo; Studart, André; Morais, Maria Vitoria; Albuquerque, António; Cavaleiro, VictorIndustrial wastes’ incorrect disposal can cause groundwater and soils contamination. In this aspect, the water treatment sludge (WTS) appears as a potential residue to be valorized within soils in order to enhance wastes’ stabilization while mitigating its environmental impacts. Therefore, geotechnical and chemical evaluations were conducted for assessing WTS’s potential as a waterproofing agent for earth works, considering their impacts on the properties of the analyzed clayey soil for assessing possible soil’ reinforcement through a further investigation. Found results on the WTS characterization have shown a high percentage of fines, which contributes for the reduction of the soil’s plasticity. In addition, its chemical composition is compatible with pozzolanic characteristics while being possible to associate the analyzed WTS with materials already used in earth works. These results indicate a solid beginning for a complete characterization of the WTS and its stabilization within soils as they indicate possible reinforcement of clayey soils and use for liners application, which have yet to be confirmed by in-depth investigations around resistance and permeability properties.
- Analysis of the chemical properties of almond and walnut shells for use in earthworksPublication . Nouioua, Thamer; Marchiori, Leonardo; Albuquerque, Antonio; Silva, Flora Cristina Meireles; Pais, Luís Andrade; Cavaleiro, VictorAlmond (AS) and walnut shells (WS) have attracted the interest of scientific community due to the possibility of developing innovative eco-friendly materials. This work aims to analyze the chemical characteristics of AS, WS, a residual granitic soil (RGS) and two mix-tures of waste:soil (10:90% and 40:60%) for evaluating their compatibility for earthworks application. Results show that both wastes could be incorporated into RGS for improving its properties and additionally can remove some water pollutants due to the presence of K2O, CaO and SiO2. This application could reduce the need to use soil natural resources, incineration of both wastes or their deposition in sanitary landfills and can promote their valorization and even create value-added products in the scope of the circular economy. However, additional studies are needed for a better understanding of their potential for using in earthworks, namely leaching, solubilization and adsorption experiments.
- Industrial solid wastes acting as barrier material for storing solid wastes and wastewaters - A critical reviewPublication . Marchiori, Leonardo; Albuquerque, Antonio; Cavaleiro, VictorClays and geosynthetic materials are commonly applied as low hydraulic conductivity layers and environmental protection barriers for storing solid wastes and wastewaters for both cover and bottom impermeabilization of geotechnical structures. However, due to a future shortage of clay materials and their high transport costs, in addition to geosynthetics generating more waste and presenting high costs, two needs emerge: reducing the amount of waste generated and developing strategies for preventing this waste from infiltrating the soil and ground water. One of the possible solutions consists in the use of some geotechnically applicable residues to prevent soil infiltration. Many by-products have been extensively studied as to their suitability as a geomaterial and showed promising results for use in liners. The most significant factors that depend on hydraulic conductivity are index, compaction, and compressive properties, so, in this aspect, hydraulic, mechanical, physic-chemical, and mineralogical properties determine the valorization, or not, of the waste as liner material. Industrial wastes and geocomposite acting as hydraulic barriers material and its geotechnical properties were reviewed and analyzed lack of research and future investigations suggestions.
- Water Treatment Sludge as Geotechnical Liner Material: State-of-ArtPublication . Marchiori, Leonardo; Albuquerque, Antonio; Cavaleiro, VictorThe periodical cleaning of the decanters at the plant generates solid wastes called water treatment sludges (WTS), a chemical compound similar to aluminum silicates. WTS’s properties have been studied for geotechnical purpose and it seems to be suitable for producing liner materials for landfills, dams, ponds, and lagoons which store and prevent soil’s infiltration of residues. Liners are usually shaped of soil and geosynthetics, their main properties required are compaction, compressibility and shear strength, chemical compatibility, and hydraulic conductivity. WTS to be considered as a soil substitute, it must be function like a soil, thus, for developing alternative materials, physical, chemical, mechanical, and hydraulic characterization laboratorial parameters are the first step to make viable its reuse. In this sense, the study aims to review the literature over the above-mentioned parameters in order to evaluate WTS as liner material. This review concluded that WTS have high heterogeneity in chemical and mechanical behavior due source of water and treatment processes. WTS’ water affinity affects plasticity behavior, and its incorporation into soils seems to contribute for a composite with pozzolanic characteristics, low specific gravity, finer granulometry, and mechanical stabilization. Although need attention on its chemical compatibility, the influence on shear resistance—increasing internal effective friction angle and decreasing cohesion—and the optimum ratio of introduction within soils for an alternative liner material. Nonetheless, there are lacks in literature over hydraulic conductivity, and long-term behavior, the use of the material in practice must be preceded by pilot tests or experimental landfills.
- Geotechnical Characterization of Water Treatment Sludge for Liner Material Production and Soft Soil ReinforcementPublication . Marchiori, Leonardo; Studart, André; Albuquerque, Antonio; Cavaleiro, Victor; Silva, AbilioA water treatment sludge (WTS) was characterized in order to evaluate if its properties would be suitable for use as liner of earthworks or for strengthening a clay soil. A WTS and a clayey soil was characterized in terms of granulometry, cumulative volumes, specific surface, density, plastic limit, liquid limit, water content, hydraulic conductivity, and characteristics of compaction (optimal water content and dry density). This study aimed to exhibit and evaluate these investigated parameters of WTS, soft soil and mixed proportions between the materials for liners’ material production while evaluating soft soils’ reinforcement feasibility. The results have shown WTS’s contribution with its fine granulometry and compaction characteristics, indicating filling properties and possible feasibility as soft soils additions for liners’ material production while being applicable for soils‘ reinforcements, corroborating with existing literature on the subject. Thus, the currently developed investigation has exposed WTS as a potential addition for these applications while also attending society’s new demands towards a more sustainable future.
- Valorização de cinzas de biomassa vegetal para aplicações geotécnicasPublication . Marchiori, Leonardo; Studart, André; Morais, Maria Vitoria; Albuquerque, Antonio; Andrade Pais, Luís; Boscov, Maria Eugenia Gimenez; Cavaleiro, VictorAs cinzas de biomassa vegetal (CBV) têm sido intensamente estudadas para incorporação em solos em obras de terra. Este trabalho tem como objetivo caracterizar química e geotecnicamente cinzas de pinheiros e oliveiras em comparação com um solo de Castelo Branco (Portugal), com a finalidade de aplicações geotécnica. Avaliações físicas, mineralógicas e químicas são necessárias para investigar a origem dos materiais, nomeadamente para determinar se as CBV têm contaminantes, como metais pesados, em sua composição e suas características físicoquímicas. Considerando que há elevadas quantidades de CBV produzidas pelo mundo e um consequente excesso de deposição em aterros sanitários ou queima, a investigação por novas soluções para a sua reutilização é cada vez mais necessária tendo em atenção quesitos atuais de desenvolvimento sustentável, redução do impacto ambiental e economia circula. A engenharia civil, nomeadamente nas áreas da construção, vias, saneamento e geotecnia, oferece várias oportunidades para investigação da aplicação destes resíduos. Neste âmbito, o reforço de solos e a aplicação de liners se destacam, pois podem beneficiar das caraterísticas físico-químicas e mecânicas das CBV para melhorarem parâmetros como a resistência mecânica e permeabilidade. Foram realizados ensaios de caracterização para as CBV e para um solo fraco, nomeadamente distribuição granulometrica, densidade específica dos grãos, limites de Atterberg, composição química por fluorescência de raio-x e mineralogia por difração de raio-x. Este trabalho faz parte de uma investigação mais ampla para desenvolver um material alternativo que possa ser utilizado em obras de terra de revestimento e reforço de solos. Os resultados demonstram que a introdução das CBV em solos pode contribuir para reduzir o peso específico e a plasticidade e melhorar as propriedades mecânicas do material, consequência também do enriquecimento de minerais pozolânicos devido à sua composição química. Desta forma, as CBV deram boas indicações para serem introduzidas em solos em diferentes percentuais, para melhorar as suas propriedades ou para a produção de liners, sendo necessário realizar futuros testes acerca do desempenho mecânico e ensaios de compressibilidade edométrica e compressão triaxial, condutividade hidráulica e potencial de lixiviação de poluentes, de modo a avaliar a sua sustentabilidade e durabilidade e afastar eventuais impactos no ambiente e saúde pública.
- Critical review of industrial solid wastes as barrier material for impermeabilization of storage waste facilitiesPublication . Marchiori, Leonardo; Albuquerque, AntonioNatural materials (e.g. clays) and synthetic materials (e.g. geosynthetics) are commonly applied as low hydraulic conductivity layers and environmental protection barriers in civil engineering works for storing solid wastes and wastewaters (e.g. solid waste landfilling, wastewater lagoons and mining waste ponds) for both covering and bottom impermeabilization of soils structures. However, due to a future shortage of clay materials and their high transport costs, in addition to geosynthetics generating more waste and presenting high costs, two needs emerge: reducing the amount of waste generated and developing strategies for preventing this waste from infiltrating the soil and ground water. One of the possible solutions consists in the use of some geotechnically applicable residues to prevent soil infiltration. Thus, the use of waste materials is particularly advantageous since it can considerably reduce construction costs, help preserve natural resources, and contribute to sustainability by turning “waste” materials into “valuable resource”. Many by-products of industry and waste (fly and bottom coal ash, blast furnace slag, foundry sands, water treatment plant sludge, agroindustry ashes, incinerated biomass ash, red mud, drilling mud and mine waste, among others) have been extensively studied as to their suitability as a geomaterial and showed promising results for use in waterproofing barriers (liners). The most significant factors that depend on hydraulic conductivity are index properties, compaction characteristics and compressive strength, so, in this aspect, hydraulic, mechanical, physical-chemical and mineralogical properties determine the valorisation, or not, of the waste as liner material. Industrial wastes and geocomposites acting as hydraulic barriers material literature were reviewed and analysed its actual applications such as lack of researches suggesting future investigations.
- Environmental-chemical compatibility of granitic-mining waste for liner materialPublication . Marchiori, Leonardo; Studart, André; Morais, Maria Vitoria; Albuquerque, Antonio; Andrade Pais, Luís; Cavaleiro, VictorMining waste is generated from extracting mineral resources and, without proper disposal, can lead to negative environmental impacts because it can contain pollutants. Emerging studies of alternatives valorizing and reusing the residue through sustainable practices. Therefore, this research investigated the potential of granitic mining waste for waterproof liner materials, considering that most used liners, clays and geosynthetics, are increasingly scarce and costly solutions, respectively. This paper aims to analyze chemical compatibility, and microscopic structure of a granitic-mining mud to produce alternative material for liner construction. It was mixed in a clay at 25% and 50% ratio to develop a waste-based geocomposites. European limits for pollutants were respected for all mixtures, and the permeability remained less than 10-9m/s, which appears to be feasible for liners production. Thus, the valorization of mining waste as liner material arises as solution for creating new waste-based added-value product in the scope of circular economy.
- Geotechnical Characterization of Vegetal Biomass Ashes Based Materials for Liner ProductionPublication . Marchiori, Leonardo; Studart, André; Morais, Maria Vitoria; Albuquerque, Antonio; Cavaleiro, VictorThis paper aims to evaluate geotechnically, chemically, mechanically, and hydraulically parameters of vegetal-based biomass ashes (VBA) and its soil incorporation with different ratios as potential liner material and soils strengthening. Composites were developed for testing with different ratios of VBA: soil, following 05:95, 10:90, 15:85, and 20:80%. All laboratorial testing program followed European standards. For geotechnical characterization, the following tests were performed for all mixtures, the soil and VBA: granulometric distribution, specific gravity and Atterberg limits. Chemical characterization was done by collecting pH values and energy-dispersive X-ray spectroscopy (EDS) parameters for elemental and oxides analysis. Also, x-ray diffraction (XRD) was done to evaluate all sample’s mineralogical description. In addition, mechanical analysis was conducted by analyzing expansibility, one-dimension consolidation through oedometer, and consolidated undrained (CU) triaxial test, along with falling head permeability for additional permeability analysis. Results have shown a finer granulometry and decrease of plasticity, 5% to non-plastic behavior, as higher amounts of VBA are introduced, exposing a filling-material behavior. EDS and XRD analysis indicate quartz, muscovite, orthoclase and calcite composition, and VBA could possibly have pozzolanic properties due to high silica-alum-ferric oxides amount. Mechanical parameters have shown a stabilization of VBA within the analyzed soil, exposing a slight reduction on settlements while increasing friction angle, 25–30º, and decreasing cohesion, 5–0 kPa. Permeability values have shown their feasibility for liners application, as found values characterizes all mixtures as low-permeability materials, especially introducing 5% of the residue into soil which values were below 10–9 m/s. Thus, the incorporation of VBA into soils paves a solid alternative for reusing this material in varied applications, as the analyzed soft soil has been geotechnically enhanced. Additional analysis, mainly pozzolanicity levels and leachability tests, can contribute for this on-going study to stablish VBA as a feasible material for the industry.