Multi-objective optimization of residential multifamily buildings to minimize cooling and heating simultaneously

Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminan

Public bus transportation system environmental impact projections regarding different policy scenario : A LCA study

Urban activities, such as transportation, are responsible for a large portion of energyrelated CO2 emissions. As the need for sustainable urban development increases, decision-makers embrace Life Cycle Assessment (LCA) as a reliable tool capable of generating scientifically based information on environmental impacts. However, there is still a lack of an analysis standard regarding the particularities of urban systems. Therefore, this research aims to define current and future environmental profiles, considering a case study of the public transport system in Porto Alegre, considering specificities of the urban context and different public policy scenarios through LCA. These results show that, although the transportation system management relies on the municipalities, the higher significance of environmental impacts depend on a national policy for using biodiesel in the diesel sold, which could lead to an increase of, for example, up to 9.4% of CO2 emissions from 2017 (baseline) to 2030. Finally, it is perceivable that to conduct a LCA to support decision-making in public urban services, a detailed approach is needed considering that technological variables interact with the territorial context and policy changes

Comparison and analysis of product stage and service life uncertainties in life cycle assessment of building elements

Life cycle assessment (LCA) has the potential to inform building decisions from the planning process to conceptual design. As such, there is intrinsic uncertainty that needs to be explored further to allow for proper decisions to be made. These uncertainties may be related to parameter definition, such as life cycle inventory or model as service life definition. This paper aims to analyze the influence of two recognized sources of uncertainties in LCA of buildings: product stage uncertainties and uncertainties from SL during the use stage. The Monte Carlo simulation method is applied to conduct uncertainty analysis of the LCA results of four building elements, namely, external cement plaster, external clay brick wall, external painting and internal painting. The functional unit is 1 m2 of each building element. Three different building reference study periods are considered: 50, 120 and 500 years. A global warming potential impact category is chosen since it is one of the most significant indicators for climate change mitigation strategies. Results indicate that SL uncertainties are greater than product stage uncertainties for the four building elements analyzed. Furthermore, based on the findings from this study, distribution choice influences the uncertainty analysis results in Monte Carlo simulation. Standardizing modeling of SL in the LCA of buildings could guide building LCA practitioners and researchers and lead to more comparable results

Sensitivity Analysis of Life Cycle impacts distribution methods choice applied to silica fume production

The construction sector is known as an important consumer of natural resources. The use of by-products from different production chains in the sector is encouraged, promoting a reduction in the extraction of natural resources, reducing the need for residues disposal and enhancing circularity. Silica fume is a by-product from the smelting process in the silicon and ferrosilicon industry, commonly used as concrete supplementary cementitious material, which provides chemical and physical effects on concrete microstructure. When LCA evaluation is conducted, different impact distribution models may be applied to assess the potential impact of the by-productss. Although their benefits are recognized, some studies still report them as burden free, having no allocated impacts . Thereby, the aim of this paper is to evaluate the differences in silica fume life cycle impacts by analyzing three scenarios from cradle to gate, considering the modeling procedures described by ISO 14040, the Cut-off model from Ecoinvent version 3.3 and the impact assessment method CML v.4.4, according to the CEN EN 15804 recommended categories. Results enhance the understanding regarding model selection and demonstrate that the selection of the proper distribution model is key, considering that this may lead to important differences in the results

Environmental assessment of urban public transport's shift from conventional to electric buses : a case study

The number of Life Cycle Assessment studies in urban public transportation focusing on modals that aim to reduce global warming impacts has been increasing significantly in the last few years. These studies suggest that the insertion of green modals on local public transportation systems could be a solution to reach sustainable development. However, the impact of this insertion in developing countries is not clear yet. Then, our main objective is to evaluate the environmental impact of an emerging city’s public transportation system, considering different public policies. Consequently, we conducted a Life Cycle Assessment study considering the transitions from Diesel to biodiesel buses and electric buses from 2020 to 2030. Three scenarios were performed, with the following criteria: battery changes, the increase of biodiesel percentage used in the fuel mix, and buses’ expected average lifespan transitioning to electric vehicles. The results show a decrease in impact by 2030 in analysed scenarios. They may support policymakers to decide whether to focus on a short-term or long-term transport policy to reduce the fleet’s sustainable impact. Particularly, electric buses have emerged as an option to reduce environmental impacts in the public transportation system in Porto Alegre, Brazil

Potential use of environmental product declaration to support green public procurement in civil construction

As compras públicas movimentam quantia considerável de recursos financeiros e têm o potencial de induzir práticas mais sustentáveis. Entretanto, permanecem barreiras para a sua efetiva implementação. O Programa das Nações Unidas para o Meio Ambiente aponta que um instrumento para auxiliar as compras públicas verdes (CPV) são fichas com informações ambientais, que facilitam a escolha e comparação entre alternativas e podem ser baseadas em técnicas de gestão ambiental como a avaliação do ciclo de vida (ACV) e/ou em declarações ambientais de produto (DAP). O objetivo deste artigo é explorar a abordagem do ciclo de vida nas CPV por meio da análise de DAP, e como suas informações podem integrar um instrumento para a construção civil. O trabalho conta com quatro etapas: análise do contexto; avaliação da estrutura das DAP; identificação das barreiras e oportunidades; investigação das DAP em CPV. Observa-se que o emprego das DAP nas fichas facilita o processo de elaboração e atualização delas, pois elas permitem a comparação entre produtos e a análise do equivalente ambiental, enquanto a ACV garante respaldo científico. Os resultados da revisão crítica mostram, ainda, que CPV são incipientes no contexto brasileiro, mas podem ser expandidas através do instrumento proposto no presente trabalho.Public Procurements move a considerable amount of financial resources and has the potential to induce more sustainable practices. However, there are barriers to the effective implementation of those practices. One of the tools recommended by the United Nations Environment Program (UNEP) to assist Green Public Procurement (GPP) are sheets with environmental information, as they help in the choice and comparison between alternatives and can be based on tools such as Life Cycle Assessment (LCA) and/or Environmental Product Declarations (EPD). The aim of this article is to explore the life cycle approach in GPP by analysing EPDs and how their information can feed the sheets for civil construction. This work was carried out in four steps: context analysis; evaluation of the structure of EPDs; identification of barriers and opportunities; investigation of EPDs in GPP. The study showed that the use of EPDs in the sheets helps the process of developing and updating them, as they allow comparisons to be made between products and the analysis of the environmental equivalent, while the LCA guarantees scientific support. The results of the critical review show the use GPP is still incipient in Brazil, but that it can be expanded through the tool proposed in this paper

ESTRUCTURA METODOLÓGICA PARA LA EVALUACIÓN DEL DESEMPEÑO AMBIENTAL EN EL PROCESO DE DISEÑO DE EDIFICIOS PÚBLICOS

The construction sector plays a leading role in global environmental impacts and, in Brazil, it has a significant portion represented by public buildings, which have legislation for the adoption of sustainability criteria in their projects, but limited practical actions. In this context, the present work proposes a methodological framework to estimate potential environmental impacts of the life cycle of Brazilian public buildings, using the technique of life cycle assessment (LCA) in the comparison of constructive solutions, during the design process. The method was structured from a systematic review on the applications of LCA in the initial phases of the project, from the analysis of the design process of public buildings and from regulations related to the LCA technique. A case study was used to test the instrument and the results indicate that, with the occasional change in a construction system with relevant impacts, significant improvements are obtained in the environmental performance of the entire life cycle of the building. A sensitivity analysis was also carried out to verify the influence of the project lifetime periods, considered for the different scenarios evaluated. It was possible to identify that, with the support of specialists, the method can contribute to the inclusion of environmental performance assessment in Public Administration.O setor da construção possui protagonismo nos impactos ambientais globais e, no Brasil, detém uma parcela significativa representada por edifícios públicos, os quais possuem legislação para adoção de critérios de sustentabilidade em seus projetos, porém limitadas ações práticas. Neste contexto, o presente trabalho propõe uma estrutura metodológica para estimar potenciais impactos ambientais do ciclo de vida de edifícios públicos brasileiros, utilizando a técnica de avaliação do ciclo de vida (ACV) na comparação de soluções construtivas, durante o processo de projeto. O método foi estruturado a partir de revisão sistemática sobre as aplicações da ACV nas fases iniciais de projeto, da análise do processo de projeto de edifícios públicos e por normativas relativas à técnica de ACV. Um estudo de caso foi utilizado para testar o instrumento e os resultados apontam que, com a alteração pontual em um sistema construtivo com impactos relevantes, são obtidas melhorias significativas no desempenho ambiental de todo o ciclo de vida da edificação. Também foi conduzida uma análise de sensibilidade, para verificar a influência dos períodos de vida útil de projeto, considerados para os diferentes cenários avaliados. Foi possível identificar que, com o suporte de especialistas, o método pode contribuir para a inclusão da avaliação de desempenho ambiental na Administração Pública.El sector de la construcción tiene un papel de destaque en los impactos ambientales globales y, en Brasil, una porción significativa del sector concierne a los edificios públicos, que tienen legislación para la adopción de criterios de sustentabilidad en sus proyectos, pero acciones prácticas limitadas. En este contexto, el presente trabajo propone un marco metodológico para estimar los impactos ambientales potenciales del ciclo de vida de los edificios públicos brasileños, utilizando la técnica de evaluación del ciclo de vida (LCA) en la comparación de soluciones constructivas, durante el proceso de diseño. El método se estructuró a partir de una revisión sistemática sobre las aplicaciones de LCA en las fases iniciales del proyecto, del análisis del proceso de diseño de edificios públicos y de la normativa relacionada con la técnica LCA. Se utilizó un caso de estudio para probar el instrumento y los resultados indican que, con el cambio ocasional en un sistema constructivo con impactos relevantes, se obtienen mejoras significativas en el desempeño ambiental de todo el ciclo de vida del edificio. También se realizó un análisis de sensibilidad para verificar la influencia de los períodos de vida útil del proyecto, considerados para los diferentes escenarios evaluados. Fue posible identificar que, con el apoyo de especialistas, el método puede contribuir a la inclusión de la evaluación del desempeño ambiental en la administración pública

Life Cycle Assessment applied to construction and demolition waste treatment : proposal of a Brazilian scenario

Important amounts of construction and demolition wastes (CDW) are currently generated in several countries. Considering the correct management of this kind of residue, and the search for its noblest use, several studies have focused on the environmental potential impacts from CDW management. Life Cycle Assessment (LCA) is often used to investigate the potential environmental impacts over the life cycle of a product, thus becoming an important tool to support decision-making. CDW recycling process produces coarse, fine and mix aggregate as outputs, characterizing a multifunctional process. But, how CDW’s LCA should be run, considering a circular and more sustainable built environment? Thus, the objective of this work is to explore the basic premises in proposing a product system for the CDW recycling process in Brazil. For this, data available in the literature on the recycling process in Brazil and in other countries support the definition of the product system. The complexity of this management option is explored, considering how the use of the recycled materials interfere in the scope, objective, unit function and other modelling choices, as well as reliability of CDW studies. Finally, the datasets provided by Ecoinvent are examined in order to promote debate on data adaptation, followed by remarks on the most appropriate choices on allocation in the CDW LCA. The cut-off system modelling associated with the new perspective on the avoided burden approach is concluded by the authors to be the most suitable for this waste recycling multifunctional processes. Understanding system models is key. When no inventory adaptation is intended, available inventory datasets are more advisable to be used when performing end of life scenarios only, once burdens differ according to countries management scenarios, as well as life cycle inventory approaches

Seleção dos agregados para produção de concreto de cimento branco

20

Valorização de resíduos de ágata em argamassas e concretos: avaliação do ciclo de vida

O uso de resíduos oriundos do processo de beneficiamento de ágata (pó de ágata) em argamassas e concretosde cimento Portland é viável tecnicamente por suas propriedades mecânicas e de durabilidade. Porém, nãoexistem pesquisas que avaliem o perfil ambiental dos materiais produzidos. O presente estudo visa avaliar osimpactos ambientais potenciais associados ao ciclo de vida de argamassas e concretos fabricados com a utilizaçãode pó de ágata como substitutivo do cimento Portland e de agregado miúdo, respectivamente. Para tanto,considerou-se proporcionamentos definidos em análises laboratoriais executadas previamente a este trabalho,em uma avaliação do berço ao portão (cradle to gate), onde foram avaliados os seguintes impactos, deacordo com a metodologia CML-IA: mudança climática, acidificação do solo e da água, eutrofização, depleçãoda camada de ozônio e depleção de recursos abióticos (fóssil e não fóssil). Resultados demonstram reduçãodos impactos potenciais de até 30%, para o uso do resíduo em substituição ao cimento em argamassas.Reduções pouco expressivas são observadas para o uso do resíduo em substituição ao agregado miúdo, porémo ganho de resistência mecânica justifica a aplicação do resíduo em casos específicos. Uma vez que todosos impactos avaliados estão fortemente relacionados ao consumo de cimento, considera-se que o uso doresíduo em substituição ao cimento é a alternativa mais ambientalmente viável, para os casos avaliados. Aparticipação dos processos relacionados ao transporte de mercadorias em todas as categorias de impacto validaa utilização de produtos produzidos/extraídos localmente. Finalmente, estudos futuros devem considerar odesempenho dos materiais produzidos, em comparação aos de referência.Palavras-chave: Avaliação do Ciclo de Vida (ACV), resíduos, construção civil