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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.
- 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.
- 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.
- Geotechnical Characterization of Biomass Ashes for Soil Reinforcement and Liner MaterialPublication . Marchiori, Leonardo; Studart, André; Morais, Maria Vitoria; Albuquerque, Antonio; Andrade Pais, Luís; Boscov, Maria Eugenia Gimenez; Cavaleiro, VictorBiomass ashes (BA) have been intensively studied as amendments for soil in earthworks. This paper aimed to geotechnically characterize BA from pines and olive trees compared to the soil from Castelo Branco, Portugal. Namely, granulometry, specific gravity, Atterberg limits and optimal compaction values were obtained and analyzed in order to valorize the residue incorporated into soils. This work is part of broader efforts to develop an alternative material that can be used in hydraulic barriers as liners and for soil reinforcement. Thus, BA can contribute to reductions in weight and plasticity, and filling properties. Further studies are needed, particularly mechanical and hydraulic performance tests.
- Geotechnical Characterization Methodology of Water Treatment Sludge for Production of Liner MaterialPublication . Marchiori, Leonardo; Morais, Maria Vitoria; Albuquerque, Antonio; Cavaleiro, VictorClayey soils and geosynthetic materials are used as low hydraulic conductivity layers and environmental protection barriers in civil engineering works for storing wastes as covering and bottom impermeabilization layer structures, known as liners. Future shortage of clay materials and geosynthetic’s high costs are usual problems, aligned with the need of prevention of environmental impacts associated to wastes by industry infiltrating into groundwater, sustainable solutions are needed. The reuse of industrial waste materials follows directives of the circular economy when this application is expected to reduce construction costs, help preserve natural resources, reduce the use of synthetic materials, reuse industrial waste materials, and contribute to sustainability. Water treatment sludges (WTS) are generated by water treatment plants mainly from periodic washing of the sedimentation tanks and filters and seems to be suitable for a geomaterial replacement. To make it feasible, the most significant factors that need more investigations are index properties, physical and mechanical behavior, chemical compaction and resistance, hydraulic conductivity, and leaching potential. A methodology for different ratios of WTS, soil, and with or without additive needing, along with a laboratorial analysis of water treatment sludge sample were proposed to ensure the expected results and parameters for liner alternative material.
- Energy Harvesting Opportunities in Geoenvironmental EngineeringPublication . Marchiori, Leonardo; Morais, Maria Vitoria; Studart, André; Albuquerque, Antonio; Andrade Pais, Luís; Ferreira Gomes, L.M.; Cavaleiro, VictorGeoenvironmental engineering involves defining solutions for complex problems, such as containment systems management, contaminant transport control, wastewater management, remediation of contaminated sites and valorization of geomaterials and wastes. In the last years, energy harvesting (EH)—or energy scavenging—methods and technologies have been developed to reduce the dependence on traditional energy sources, namely fossil fuels, and nuclear power, also responding to the increase in energy demands for human activities and to fulfill sustainable development goals. EH in geoenvironmental works and the surrounding soil and water environment includes a set of processes for capturing and accumulating energy from several sources considered wasted or unusable associated with soil dynamics; the stress and strain of geomaterials, hydraulic, vibrations, biochemical, light, heating and wind sources can be potential EH systems. Therefore, this work presents a review of the literature and critical analysis on the main opportunities for EH capturing, accumulating and use in geoenvironmental works, among basic electric concepts and mechanisms, analyzing these works in complex conditions involving biological-, chemical-, mechanical-, hydraulic- and thermal-coupled actions, concluding with the main investigation and challenges within geoenvironmental aspects for EH purposes.
- Cracking and desiccation of water treatment sludge for incorporation into soils for alternative liner material productionPublication . Marchiori, Leonardo; Morais, Maria Vitoria; Albuquerque, Antonio; Ferreira-Gomes, L.M.; Cavaleiro, VictorCracks may lead to hydraulic failure in soils due to increase of hydraulic conductivity which facilitate water infiltration, impacting negatively for liner materials. Therefore, cracking and desiccation investigation on liner material is advised. Water treatment sludge (WTS) is a by-product resulting from water treatment plants, and it seems to be suitable for geotechnical applications and soil replacement due to hydraulic latent properties, chemical similarities to soils, and mechanical behaviour. In this work WTS samples were incorporated into soil in different ratios – 05%; 10%; 15% and 20% of waste in dried mass of the geocomposites. The four mixtures, a soil sample and a WTS were tested according to the following procedure: two different circular Petri dishes samples were used, 5mm(H5) and 10mm(H10), and two cylindrical compacted samples with 65-70mm of diameter and 20-140mm of height (EDO-TRI, respectively) - dried for 10 days in controlled temperature and humidity. Water release curves (WRC), digital images correlation supported Crack Intensity Factor (CIF) index results were obtained for each material. Cracking behaviour results were compared with the permeability through falling head laboratorial tests, and studies around WTS ratio. Composites with 10% and 15% had the best results, showing no cracks during Petri dishes procedures for H10, in addition, the permeability for these materials reached the maximum for liner production – 10-9 m/s according to European and American directives - making possible the development of an alternative and feasible liner material.