RESUMO

In the present work, a study was carried out on the dosage of wastes from the chemical industry (tannery sludge) and civil construction (concrete and plaster) in mixtures used in concrete blocks' production. The objective was the application of these blocks in paving. The characterization of the materials used was performed employing X-ray diffractometry (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The effect of the different residues on the blocks' properties was evaluated through compressive strength, flexion-traction, water absorption, abrasion resistance, and leaching tests. The results indicated that the concrete paving blocks produced with the addition of residues did not obtain gains in the values of mechanical resistance to compression and traction in bending compared to blocks made with standard raw material. However, the blocks produced with construction waste presented satisfactory results for application in street paving after 7 days of concrete curing, reaching values between 36.54 and 44.6 MPa for the mentioned properties. These values also increased to 21.4% within 28 days of curing. The blocks produced with plaster showed values between 37.03 and 39.85 MPa after 28 days of curing, allowing their use for street paving. On the other hand, the blocks containing residues from the chemical industry had lower strengths, reaching a maximum of 29.36 MPa after 28 days of curing. In addition, it was also noted that the blocks produced with recycled concrete showed an improvement in performance for a composition of 50% recycled material.

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RESUMO

The building industry generates millions of tons of construction and demolition waste annually (12 million tons/year are generated in Mexico, of which only 4% is reused or recycled). Concomitantly, the demand for goods and services by the building industry causes significant environmental impacts. On the other hand, plastic waste is also difficult to assimilate into the environment in the short term, and its recovery is of special interest. Therefore, this research focuses on the feasibility of the manufacture of Partition Blocks (essential building element) through the combination of construction and demolition waste (CDW), polyethylene terephthalate (PET) plastic flakes, dust from tire shredding, and residue from the sugar industry (bagasse). The results of this study show that the Partition Blocks made with CDW and PET reach an average compressive strength of 115.003 kgf/cm2 (11.278 MPa) (suitable for structural use according to Mexican regulations); the use of lime enhances the consistency of the mixture of CDW and PET (increases its cohesion and homogeneity); and finally, these Partition Blocks have a cost comparable to the current conventional Partition Blocks made with virgin material, thus, conferring them validity as a feasible recycling option for these residues.

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RESUMO A disposição inadequada de resíduos da construção civil (RCC) gera poluição difusa em grande parte do território brasileiro, a despeito da legislação ambiental vigente. A incipiência do planejamento de sistemas de gestão de resíduos, no âmbito municipal, e também de seu monitoramento com vistas à melhoria contínua foi o agente mobilizador desta pesquisa, que se propôs a determinar e validar variáveis para um conjunto de indicadores de efetividade de gestão de RCC e, por meio deles, avaliar a gestão dos RCC no município de São José dos Campos, São Paulo. Trata-se de uma pesquisa aplicada com dados quanti-qualitativos, tendo em vista a utilidade pública. Os 15 indicadores de efetividade foram avaliados com o auxílio de 124 variáveis de diferentes significâncias determinadas pelos gestores municipais. O uso da ferramenta para a avaliação de desempenho em São José dos Campos mostrou que, mesmo sendo o município considerado referência nacional na gestão de RCC, ainda há esforços a serem invitados para que essa gestão possa ser considerada efetiva, principalmente nas dimensões econômica e social. Os indicadores e variáveis apresentados no presente trabalho podem nortear avaliações em outros municípios brasileiros, desde que consideradas as especificidades locais.

ABSTRACT In spite of current environmental legislation, inadequate disposition of construction solid waste (CSW) generates diffuse pollution in a large part of Brazilian territory. Many incipient plans of waste management systems, at the municipal level, and also their monitoring needs for having continuously improved systems were the mobilizing agents of this research, which proposed to determine and validate variables for a set of CSW management effectiveness indicators and through them to evaluate the management of CSW in the municipality of São José dos Campos. It is an applied research with quantitative and qualitative data, with a view to public utility. Fifteen effectiveness indicators were evaluated using 124 variables with different scores determined by the municipal managers. As a result of using the performance evaluation tool, it was showed that, even though São José dos Campos is considered nationwide as reference in the management of CSW, it is still necessary to invite efforts so that its management can be considered effective, mainly in the economic and social dimensions. All indicators and variables presented in this study may guide evaluations in other Brazilian municipalities, as long as respect for local specificities is maintained.

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The construction sector generates 14,000 t/d of construction waste in Mexico City, these materials do not have real applications and end up accumulating in landfills. This work, the objective of which was to analyze the physicochemical and mineralogical properties of soil and construction waste used in the manufacture of Recoblocks, is divided in five stages. First, the excavation material was submitted to field tests. Physical and chemical tests were then carried out on construction waste. Subsequently, the optimal mixture for making Recoblocks was determined. Next, Recoblocks were evaluated and compared with blocks made with water only, without mucilage of Opuntia ficus, and finally a feasibility study was performed. The X-ray diffraction study showed the presence of plagioclase, minerals that improve bending resistance, hardness, durability, as well as resistance to stress in a material. Compared to blocks manufactured without mucilage, the use of Opuntia ficus mucilage increased the compressive strength of the material by 59%, as well as the erodibility. Recoblocks are an environmentally friendly option because they are based on recycled materials, dried under the sun, which eliminates the use of brick oven. The production cost per unit is just USD 0.19, so it is a viable option as a building material.

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RESUMO Este trabalho teve como objetivo geral desenvolver um modelo de avaliação da viabilidade econômico-financeira da implantação de usinas de reciclagem de resíduos da construção civil e demolição (URRCD) em municípios brasileiros. O modelo de avaliação proposto para cada projeto de investimento (PI) em estudo uniu o modelo de negócio Canvas, o plano de negócios, a metodologia multi-índice proposta por Souza e Clemente (2009) e ampliada por Lima et al. (2015) por meio do aplicativo web $AVEPI. Também foi realizada uma análise de sensibilidade por meio de limites de elasticidade e valores-limite, bem como uma análise estocástica utilizando a simulação de Monte Carlo (SMC). Com base na proposição desse modelo, este foi aplicado em um estudo de caso no município de Pato Branco (PR). Os resultados mostram que há viabilidade econômico-financeira na implantação desse PI, uma vez que o valor presente líquido médio é de aproximadamente R$ 583.919,87, e a recuperação do investimento se concretizará em 12 anos (payback). Por meio da SMC, visualizou-se que há alta probabilidade (99,78%) de que o investimento na URRCD de Pato Branco seja rentável. Entretanto, os índices de elasticidade mostraram que é preciso monitorar as receitas esperadas e os custos estimados com mais atenção. Assim, será preciso um trabalho, por parte dos gestores da URRCD, em prol de sempre estarem buscando aumentar a demanda pelos agregados reciclados, como maneira de aumentar a receita da usina, desde que se respeite a sua capacidade de produção.

ABSTRACT This work had as main objective to develop an evaluation model for analyzing the economic and financial feasibility of implementing Construction and Demolition Waste Recycling Plants (URRCD) in Brazilian municipalities. The evaluation model proposed for the Investment Project (IP) under study was performed using the business model Canvas, the business plan, the multi-index method proposed by Souza and Clemente (2009) and expanded by Lima et al. (2015) through the $AVEPI Web app. Also, a sensitivity analysis was performed, through the elasticity limits and limit values as well as a stochastic analysis using the Monte Carlo Simulation (MCS). From the proposition of this model, it was applied in a case study in Pato Branco, Paraná. The results showed that there is economic and financial viability in the implementation of this IP, since the average Net Present Value (NPV) is about R$ 583,919.87 and the investment recovery will materialize in 12 years (Payback). Through MCS, it was observed that there is a high probability (99.78%) that the investment in the URRCD of Pato Branco, Paraná, be profitable. However, the elasticity indices showed that it is necessary to monitor the expected revenues and the estimated costs with more attention. Thus, it will require a work by the managers of the URRCD, in favor of always seeking to increase the demand for recycled aggregates, as a way to increase the revenue of the plant, as long as it does not exceed its production capacity.

RESUMO

Construction waste is generated during construction and remodelling undertakings. Construction waste management (CWM) is a challenge in developing countries such as Brazil. Thus, it is necessary to create tools by which CWM may be evaluated. This article presents the elaboration of a tool to assess CWM in Brazilian cities; moreover, this method facilitates such analyses in regions which lack substantial quantitative data. In doing so, the tool, known as the Assessment Index for Construction Waste Management (ICWM), combines quantitative and qualitative information and is composed of 49 indicators and 19 criteria divided into the following groups: operational; environmental; politico-economic, educational; and social. The analytic hierarchy process was used to assign the weights attributed to the groups and criteria to build the index. The indicators were measured according to a standardized rating scale proposed for each one. These elements were aggregated in a mathematical formula that enables the calculation of the ICWM. The aggregation method used was a weighted linear combination, and the index is rated on a 0 to 1 scale. The ICWM was tested in four municipalities. In all cases, the management was considered inefficient. The proposed tool proved to be effective in evaluating the CWM. In cities where the ICWM was tested, it was possible to identify the significant deficiencies of the CWM and recommend improvement actions to develop more efficient and sustainable management.

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RESUMO Esta pesquisa buscou avaliar a capacidade de retenção de Pb2+, Cd2+, Cr3+ e As5+ por dois tipos de solo, um Latossolo argiloso e um arenoso, por resíduos da construção civil (RCC) e por misturas contendo 70% dos referidos solos e 30% de partículas finas de RCC. Para isso, foram realizados ensaios de equilíbrio em lote em amostras dos cinco sorventes (RCC, solo argiloso, solo arenoso, misturas solo argiloso-RCC e solo arenoso-RCC) às quais foram adicionadas soluções monoespécie de chumbo, cádmio e cromo na forma de nitrato, e arsênio na forma de arsenato de sódio, o que permitiu avaliar como cada elemento interagiu com cada amostra. Foram ensaiados 5 lotes de amostras, em triplicatas, com a mesma razão sorvente solução de 1:20, em que se variaram as concentrações das soluções. Curvas teóricas de sorção de Freundlich e de Langmuir foram utilizadas para ajustar os pares de pontos obtidos experimentalmente, concentração de equilíbrio do soluto na solução (Ce) versus massa de soluto sorvida por massa de solo (S). Os resultados obtidos permitem afirmar que os RCC apresentaram maior capacidade em sorver Pb2+, Cd2+ e Cr3+, enquanto o As5+ é mais fortemente sorvido pelo solo argiloso e pela mistura solo argiloso-RCC; os processos sortivos do Pb2+, Cd2+ e Cr3+ diferem daquele do As5+, uma vez que os primeiros comportam-se como cátions no solo e o último comporta-se como oxiânion. O solo argiloso, por possuir maior teor de matéria orgânica, exibe maior sorção dos metais estudados do que o solo arenoso.

ABSTRACT This study evaluated the retention capacity of Pb2+, Cd2+, Cr3+ and As5+ per two types of soil, a clayey Latosoil and a sandy soil, by construction waste and mixtures containing 70% of soil and 30% of construction waste's particles. For this, batch equilibrium tests were performed with samples of the five sorbents (construction waste, clayey soil, sandy soil, mixtures of clayey soil-construction waste and sandy soil-construction waste) added to monospecie solutions of lead, cadmium and chromium in the form of nitrate; and arsenic in the form of sodium arsenate, allowing the evaluation of how each element interacted with each sample. Five batches of samples were tested, in triplicate, with the same sorbent solution ratio, 1:20, and the concentrations of the solutions varied. Freundlich and Langmuir's theoretical sorption curves were used to adjust the pairs of data points, the equilibrium concentration of solute in the solution (Ce) versus the solute mass sorbed per soil mass (S). The results allow concluding that the construction waste had greater ability to absorb Pb2+, Cd2+ and Cr3+. As5+, however, is more strongly sorbed by the clayey soil and by the mixture clayey soil-construction waste. The sorptive processes of Pb2+, Cd2+, and Cr3+ differ from the sorptive processes of As5+, because the first ones behave as cations in the soil, while the latter behaves as oxyanion. Finally, the clayey soil showed greater sorption capacity than the sandy soil for all the metals studied, as clayey soil has a higher organic material content.

RESUMO

The expressive generation of construction and demolition waste is stimulating several studies for reusing this material. The improvement of soft soils by concrete compaction piles has been widely applied for 40 years in some Brazilian cities. This technique is used to improve the bearing capacity of soft soils, allowing executing shallow foundations instead of deep foundations. The compaction piles use a high volume of material. This article explored the possibility of using recycled aggregates from construction waste to replace the natural aggregates in order to improve the bearing capacity of the soft soil, regarding its compressive strength. Construction wastes from different stages of a construction were used in order to make samples of concrete with recycled aggregates. The strength of concretes with natural aggregates was compared with the strength of concretes with recycled (fine and coarse) aggregates. Results show that all samples met the minimum compressive strength specified for compaction piles used to improve the bearing capacity of soft soils. The concrete with recycled aggregate from the structural stage had even higher resistances than the concrete with natural aggregates. This behaviour was attributed to the large amount of cementitious materials in the composition of this type of concrete. It was also observed that concrete with recycled fine aggregate has a superior resistance to concrete with recycled coarse aggregate.

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RESUMO

O objetivo do presente trabalho é fazer uma análise crítica do Decreto Estadual de São Paulo nº 60.520/2014 que instituiu o Sistema Estadual de Gerenciamento Online de Resíduos Sólidos – SIGOR - Módulo Construção Civil da Secretaria do Meio Ambiente do Estado de São Paulo. Os resíduos de construção civil (RCC) e demolição (RCD) são provenientes de construções, reformas, reparos e demolições de obras da construção civil. As pequenas construções e obras de reforma são responsáveis pela maior quantidade gerada desses resíduos, não obstante, as normas que estabelecem critérios e procedimentos para a gestão dos resíduos da construção civil, quanto à destinação final ambientalmente adequada, não estão devidamente contempladas no Decreto Estadual 60.520/14. Desta forma, o Sistema Estadual de Gerenciamento Online de Resíduos Sólidos – SIGOR - Módulo Construção Civil não se mostra suficiente para impedir o descarte irregular de resíduos da construção civil, que é constatado e confirmado pelos próprios órgãos responsáveis pela gestão e gerenciamento destes resíduos.

The objective of this work is to make a critical analysis of the São Paulo State Decree nº 60,520/2014 which established the State of Online Management System of solid waste-Construction module of SIGOR Secretaria do Meio Ambiente do Estado de São Paulo. Construction waste (RCC) and demolition (RCD) come from buildings, renovations, repairs and demolition of the construction works. Small construction and renovation are responsible for the largest amount of such waste generated, notwithstanding, the rules that establish criteria and procedures for the management of construction waste, regarding environmentally appropriate final disposal, are not properly covered by State Decree 60,520/14. In this way, the State System of Online Management of solid residues – SIGOR-Construction Module was not enough to prevent the irregular disposal of construction waste, which is verified and confirmed by the bodies responsible for the Administration and management of these wastes.

Assuntos

RESUMO

O objetivo do presente trabalho é fazer uma análise crítica do Decreto Estadual de São Paulo nº 60.520/2014 que instituiu o Sistema Estadual de Gerenciamento Online de Resíduos Sólidos SIGOR - Módulo Construção Civil da Secretaria do Meio Ambiente do Estado de São Paulo. Os resíduos de construção civil (RCC) e demolição (RCD) são provenientes de construções, reformas, reparos e demolições de obras da construção civil. As pequenas construções e obras de reforma são responsáveis pela maior quantidade gerada desses resíduos, não obstante, as normas que estabelecem critérios e procedimentos para a gestão dos resíduos da construção civil, quanto à destinação final ambientalmente adequada, não estão devidamente contempladas no Decreto Estadual 60.520/14. Desta forma, o Sistema Estadual de Gerenciamento Online de Resíduos Sólidos SIGOR - Módulo Construção Civil não se mostra suficiente para impedir o descarte irregular de resíduos da construção civil, que é constatado e confirmado pelos próprios órgãos responsáveis pela gestão e gerenciamento destes resíduos. (AU)

The objective of this work is to make a critical analysis of the São Paulo State Decree nº 60,520/2014 which established the State of Online Management System of solid waste-Construction module of SIGOR Secretaria do Meio Ambiente do Estado de São Paulo. Construction waste (RCC) and demolition (RCD) come from buildings, renovations, repairs and demolition of the construction works. Small construction and renovation are responsible for the largest amount of such waste generated, notwithstanding, the rules that establish criteria and procedures for the management of construction waste, regarding environmentally appropriate final disposal, are not properly covered by State Decree 60,520/14. In this way, the State System of Online Management of solid residues SIGOR-Construction Module was not enough to prevent the irregular disposal of construction waste, which is verified and confirmed by the bodies responsible for the Administration and management of these wastes.(AU)

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RESUMO

Brazil, as a result of economic development and strengthening of the construction industry in recent years, is generating an increasing amount of construction and demolition waste (CDW). Hence, environmental assessment of the management systems is vital. A life cycle assessment (LCA) is presented of CDW management in a medium-sized municipality located in the southeast region of Brazil, where the impacts of leaching were not considered due to absence of consistent data. Six different proposed scenarios for the current CDW management situation have been considered. These scenarios comprised the combined use of landfilling, sorting, and recycling, and the use of CDW as paving material for landfill roads, in different percentages. Considering 0.8 ton of waste as the functional unit, the life cycle inventory was performed using primary data obtained from field survey and secondary data from the database Ecoinvent version 3.1, and from the literature. The method CML 2 baseline 2001 was used for environmental impacts evaluation. The results highlight that recycling is beneficial when efficient CDW sorting takes place at construction sites, avoiding the transport of refuse to sorting and recycling facilities, and the distance between the generation source and the recycling unit is within 30 km. Thus, our results are helpful to ensure that the decision-making processes are based on environmental and technical aspects, and not only on economic and political factors, and also provide data and support for other LCA studies on CDW.

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