Dissertações em Engenharia de Infraestrutura e Desenvolvimento Energético (Mestrado) - PPGINDE/NDAE/Tucuruí

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/9401

Navegar

Agora exibindo 1 - 20 de 20

Acesso aberto (Open Access)
Análise da viabilidade técnico-econômica de implantação de reciclagem de pneus para produção de CBUQ em Tucuruí
(Universidade Federal do Pará, 2019-02-21) MOUSINHO, Mateus Mamede; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Population growth and rapid technological development have contributed to increased solid waste generation by improperly disposing of post-consumer tires, which are not biodegradable and their decomposition time is not yet precisely determined. To be defended that the recycling culture does not only show aspects of environmental and educational preservation, it is also necessary to justify recycling as an economic activity that generates employment and income to the city, contributing to the well-being and quality of life. Therefore, the main objective of this research was to quantify the discard of waste tires and to analyze the technical-economical feasibility for the implementation of the recycling process of waste tires in the production of rubber aggregate in the asphalt mixture at the city's asphalt plant. To do so, it was measured the disposal of waste tires in a given period in Tucuruí and estimated the disposal volume of the adjacent cities, in addition, it was analyzed the operational activities and production costs of the waste as a rubber aggregate. In the field survey, 98 questionnaires were applied in 30 neighborhoods where the establishments were in January 2018. Thus, there was a monthly amount of 1,664 tires in the rubber workshops, 2,347 tires in the mechanical stores, totaling 4,011 tires in the municipality, which allows to conclude that the city presents a large volume of this solid residue. Adjacent cities presented in their estimate a total of 8,031 tires unserviceable per month. For the production of the rubber aggregate asphalt mixture, the conventional CBUQ trait was used in relation to the modified CBUQ developed by Coelho (2018), in which it was estimated that one kilometer of asphalt mixture of thickness of 3,5 centimeters can be used approximately 11.72 tonnes of recycled aggregate (8.79 tonnes of rubber and 2.93 tonnes of wood sawdust), this is equivalent to 1,465 car tires or 5,170 motorcycle tires, leading to an economy in the purchase of raw material from R$ 56,075.41 per kilometer. It is concluded that the results of the three scenarios are satisfactory, the simulations of the study were only the resources available to produce the rubber aggregate generated by the municipality as a pioneer project, with the intention that other municipalities are part of this visual identity of sustainable city.
Acesso aberto (Open Access)
Análise das propriedades tecnológicas da cinza do caroço de açaí na cerâmica vermelha
(Universidade Federal do Pará, 2019-09-16) FERREIRA, Taiana da Silva; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783; ISHIHARA, Júnior Hiroyuki; http://lattes.cnpq.br/3498874642887006; https://orcid.org/0000-0002-0081-7913
The raw materials from the exploration of deposits used for the manufacture of products used in construction and the environmental impacts caused by the red ceramic sector evolved as cities developed. The need for the use of alternative materials, such as waste biomass, has become increasingly necessary studies aimed at the reuse of waste in the process of production and manufacture of ceramic materials. Thus, this work has the objective of evaluating the incorporation of ash from the acai kernel residue (RCA) in the clay mass and to evaluate the technological properties of red ceramic. The materials were chemically and physically characterized, and then extruded specimens were molded using 0%, 10%, 15% and 20% RCA ash mixed in two types of clay, called red clay and dark clay. After firing at 950 ºC, the pieces were subjected to water absorption, apparent porosity, specific gravity, linear shrinkage and flexural strength stress tests. The results showed that the use of RCA ash contributed to the workability of the mixtures, reducing the need for additional water for molding. It was also verified that the 10% ash content as a partial substitute of red clay, and the mass containing 50% of red clay and 50% of dark clay, had a positive influence on the evaluated technological properties. However, for the 20% ash incorporation of RCA, the values were median and for the unsatisfactory porosity assay. Thus, it was possible to verify the technical feasibility of using açaí stone ash in partial substitutions, contributing to the reduction of raw material exploration, reduction of solid waste disposal and the reuse of the residual biomass of açaí stone in the production of ceramic materials.
Acesso aberto (Open Access)
Análise de atributos de classificação para o diagnóstico de falhas em rolamentos baseado em SVM
(Universidade Federal do Pará, 2019-08-06) SOUZA, Jusley da Silva; BAYMA, Rafael Suzuki; http://lattes.cnpq.br/6240525080111166; MESQUITA, Alexandre Luiz Amarante; http://lattes.cnpq.br/3605920981600245; https://orcid.org/0000-0001-5605-8381
In industries, the concern in total availability of machines and the mechanical equipment in the productive area it’s subject of research and tests to obtain more efficient techniques to be applied for monitoring and faults’ diagnosing. Bearings are machine elements of great application in the industrial area and they present high fault index that generate machine’s stops to carry out maintenance. For this reason, this paper presents Artificial Intelligence technique applied to the vibration signals of a rotary machine for fault diagnosis in its bearings. The vibration signals are part of an open database offered by Case Western Reserve University. In this paper the Support Vector Machine (SVM) classification algorithm is applied in two ways for the rolling bearings faults’ diagnosis. In the first case statistical predictors (Root Mean Square Value, Crest Factor, K Factor, Kurtosis and Skewness) are used as features for the SVM classifier. In the second case, the signal processing is performed by applying the Ensemble Empirical Mode Decomposition (EEMD), which generates several signals called Intrinsic Mode Functions (IMFs). For each IMF, it’s modeled using Autoregressive Modeling (AR), and the AR modeling coefficients of each IMF are used as features for the SVM classifier. The analyzes are performed for training and validation groups, with randomly chosen window and with temporal sequence chosen window, considering two classification problems within the same data, the first one considers the same severity and only changes the fault type and the other vary both severity and fault type. As result, both methodologies presented excellent reliability results for bearing faults’ diagnosis.
Acesso aberto (Open Access)
Argamassa autonivelante para contrapiso: efeito do tipo de cimento no comportamento físico-mecânico
(Universidade Federal do Pará, 2020-04-24) ALVES, Brenda Maiara Oliveira; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Self-leveling mortar (SLM) is inserted in the construction market as an innovative product due to its special properties when compared to conventional mortars due to the filling of empty spaces and self-compacting only under the effect of gravity, the ability to flow and level without the occurrence of segregation. The use of CP V – ARI cement is common for its production, since its high fineness favors the fluidity of the material and for providing fast hardening, fundamental characteristics that must be considered in self-leveling mortars (SLM’s). However, the rare availability of this type of cement becomes a limiting factor for its applicability in the region. Therefore, the objective of this research is to develop the study of SLM dosage for screed, adapting it to local materials that favor its design and evaluating its influence on rheological and mechanical characteristics. For the production of these mortars, we used the adaptation by Lopes et al. (2018) of Tutikian's methodology (2004) for self-compacting concrete (CAA), using fines in partial replacement of cement, adopting as controllable factors the type of cement (CP I, CP II-E, CP IV and CP V-ARI) and the type of mineral addition (silica fume and metakaolin). For the characterization of SLM in the fresh state, the mini slump, mini V-funnel, flow retention, mass density and incorporated air content, determination of exudation and healing time tests were performed. In the hardened state, the mechanical resistance to compression and traction in flexion and the retraction of these materials were verified, since it is one of the main pathologies of SLM. Analyzing the results obtained, it was observed that the surface area of the tested cements was the factor that most influenced the performance of the produced mortars, where cements with larger surface areas needed more additive to achieve fresh properties and had the highest rates of retraction. Mineral additions contributed to the cohesion of mortars and reduced shrinkage in mixtures with contents of up to 25% metakaolin and 15% silica fume.
Acesso aberto (Open Access)
Avaliação da influência de sistemas de proteção na permeabilidade de água em placas cimentícias com incorporação de perolas de poliestireno expandido
(Universidade Federal do Pará, 2025-04-24) GOMES, Saulo de Almada; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Water is one of the main elements responsible for the emergence and propagation of pathological events in coatings. Its permeated presence compromises the protective capacity, as well as directly influences durability, and can accelerate the deterioration of mortars, impairing their useful life. It is known that the use of surface protection instruments (painting system) and the use of waterproofing additives in the production of mortar coatings directly influence the protection against water permeability. Within this aspect, this study aimed to evaluate the degree of influence of protection systems for cement boards with the incorporation of Expanded Polystyrene (EPS). EPS was used in the cement board as a partial replacement for sand, in a volume of 20%. Two types of painting systems were evaluated, one for indoor environments and the other for outdoor environments, in addition to a type of waterproofing water-repellent additive, which was applied to the mortar mixture. This evaluation was carried out using two methods that analyze the permeability of mortar coatings: the Karsten tube test (pipe method) and the permeability test of ABNT NBR 15498/2021, which deals with the requirements for using cement boards. The mechanical properties of the mortars and boards were also characterized. The results of this work demonstrated that the protection systems evaluated caused different effects on the permeability of the boards. The waterproofing additive did not significantly influence the permeability of the panels, only the physical characteristics, with greater emphasis on the mass density and water absorption properties. The painting systems positively influenced the waterproofing capacity of the panels, with the external painting system being more efficient. Regarding the permeability assessment techniques, the Karsten tube showed great variability in the results, demonstrating that this technique is more sensitive to the conditioning variables. And, in the permeability test of NBR 15498, all panels passed the use requirement.
Acesso aberto (Open Access)
Avaliação do emprego de agregado miúdo reciclado na produção de peças pré-moldadas para pavimentação tipo “paver”
(Universidade Federal do Pará, 2021-02-05) VIEIRA, Marília de Oliveira; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
Acesso aberto (Open Access)
Captura de carbono em placas de concreto permeável
(Universidade Federal do Pará, 2020-06-12) SANTOS, Caio José Bastos Marques; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
The production of cement has an impact on the environment from the release of co2 where carbon dioxide acts directly on the phenomenon of "greenhouse effect". Although cement production generates high rates of carbon dioxide, cement hydration products have the ability to reabsorb carbon dioxide from a physical-chemical phenomenon called carbonation. This research related this physical-chemical phenomenon to a material considered sustainable, such as permeable concrete. This type of concrete can be used on non-reinforced floors. The research focuses on analyzing the ability to capture co2in permeable concrete slabs. As for carbonation, mixtures produced with two granulometric bands of pebble and CP II F agglomerate with a/c ratios of 0.33 and 0.37 were analyzed in protected and unprotected environments, and in an accelerated environment in a co2 chamber. A chemical phenolphthalein indicator was used to assess the occurrence of carbonation in five ages of reading and image analysis software to study the carbonated surfaces. The material showed satisfactory results in terms of mechanical, water and carbonation depth parameters, having reabsorbed the atmosphere gas from the cement paste that surrounds the aggregate grains of the material's granular skeleton.
Acesso aberto (Open Access)
Concreto auto adensável com agregado miúdo reciclado de concreto
(Universidade Federal do Pará, 2019-03-29) BERNARDO, Karen Suely Martins; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
A more sustainable approach in the production of self-compacting concrete (SCC) aims to replace the natural aggregates by recycled concrete aggregates, however this substitution affects the properties of the concrete produced. This research propose evaluate the effect of the fine recycled aggregate on the properties in the fresh and hardened state of self-compacting concrete using a methodology of dosage focused on the rheology of materials. The dosage study was performed through an adaptation of the Gomes method, and four levels of FNA substitution by FRCA were determined (10%, 20% and 30%). Were analyzed the fresh state properties according to the parameters established according to the specifications on the subject and by the normative prescription of reference, and the properties in the hardened state. In this study, was observed a decrease in apparent viscosity, passing ability and segregation resistance, proportional to the increase in FNA substitution. However, all mix designs have attend the required of self-compacting, with minimum adjustments. All concretes obtained axial compressive strength at which fit in the structural concrete class. Therefore, through the responses founded during the dosing study, it was possible to produce self-compacting concretes with 30% of FRCA that met the requirements established.
Acesso aberto (Open Access)
Desenvolvimento de um aplicativo móvel para promover o reaproveitamento de resíduos na dosagem de concreto
(Universidade Federal do Pará, 2019-09-04) MESQUITA, Felipe José Marques; FÜLBER, Heleno; http://lattes.cnpq.br/5018616409948511; ISHIHARA, Júnior Hiroyuki; http://lattes.cnpq.br/3498874642887006; https://orcid.org/0000-0002-0081-7913
Concrete is the most widely used building material in the world, resulting in high consumption of natural materials, thus, the reuse of waste in substitution of cement and aggregates in the production of concrete enables reduction of greenhouse gas emissions, reduction in extraction of natural raw materials, in addition to the reduction on the disposal of these wastes in nature. Given the need to develop solutions that contribute to the efficient reuse of waste, this paper aimed to analyze the state of the art of national production of concrete with waste reuse, to develop a mobile application to promote the reuse of waste in concrete production. Through bibliometric analysis of Brazilian publications on concrete with reuse of waste, we analyzed works published over a period of 20 years in the Web of Science database, revealing growing interest on the subject, especially the construction and demolition waste, being this the most published and protagonist residue of the most influential article on the subject. The analysis of the publications allowed the creation of a knowledge base on the use of waste in concrete production. These data were used in the development of an application for Android mobile devices, which allows the user to have easy access to concrete dosages with reuse of residues, obtain information on potential waste suppliers and calculate the production costs of this concrete. The system has 41 different mix proportioning, including 7 concrete types and 10 waste options, allowing the user to achieve environmental gains by replacing up to 100% of natural concrete aggregates with waste and saving up to 11.82% over cost. of concrete produced without waste. Keyword: concrete, waste, database, application, bibliometrics.
Acesso aberto (Open Access)
Estudo da colmatação em concretos permeáveis para tráfego leve e de pedestres
(Universidade Federal do Pará, 2020-05-28) TEIXEIRA, Mísley da Cruz; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Permeable concrete is a material mostly used as paving coating to reduce the effects of surface sealing. The material’s susceptibility to clogging is considered as a disadvantage, and it became an object of study in research about this material, as this one which evaluated the effect of clogging on permeable concretes used as pavement coating to light traffic. To this end, an experimental program was elaborated to characterize the material, designed with different percentages of fine aggregate, and to evaluate the evolution of clogging in permeable. The specimens were submitted to characterization and permeability tests after deposition cycles of different types of sediments (sand and clay) and cleaning by aspiration. The results of fresh material characterization corroborated the common assertion in the academic community that the insertion of fine aggregate in mix compositions increases the unit mass and the mechanical strengths and reduces the void percentage and the permeability of the concretes. The clogging tests proved that larger particle size sediments (sand) caused a loss of permeability due to sealing of the upper layer of the specimen, with loss ratios up to 21,13% at the end of the 20th sedimentation cycle, while the smaller particle size sediments (clay) induce to a deeper clogging, with a permeability reduction varying of 8,45% to 16,46%. The maintenance efficiency was proven by total recovery of clogging by sand, and a recovery percentage of 96,85% to clogging by clay. These results make it possible to declare that any particle size can clog the material, but also it is easy to recover its permeability by maintaining/cleaning of the pavement, which confirms that the pavement lifespan and raining capacity are directly associated to its periodic cleaning.
Acesso aberto (Open Access)
Estudo da potencialidade da cinza da casca do murumuru, um resíduo agro industrial amazônico como filler ao concreto estrutural
(Universidade Federal do Pará, 2022-11-17) SOUZA, Milleno Ramos de; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042; TEIXEIRA, Marcelo Rassy; http://lattes.cnpq.br/8912916360456192
The use of agro-industrial waste in the partial replacement of cement in concrete has been the subject of research that analyzes the possible improvements in mechanical and physical properties and durability of the concrete, in addition to providing the use of mineral additions of natural origin or partial replacement in relation to the constituent materials of the composite, waste that would have inappropriate disposal, such as open-air landfills and burning. With this scenario, the study aims to research the use of murumuru husk ash (MHA), an agro-industrial waste generated specifically in the Amazon region as partial replacement of cement in structural concrete and evaluate the physical, chemical and mineralogical characteristics of the ash to act as filler in concrete, and its properties in the fresh and hardened state in concrete. With this purpose, the MHA underwent the physical-mechanical characterization tests such as specific mass, pozzolanic activity with Portland cement, pozzolanic activity with lime and BET test, also performing the mineralogical and chemical analysis of the ash. For concreting, a mix 1:1.6:2.4 (by mass) with water/cement ratio of 0.43 was considered, with replacement levels of 0%, 6%, 9% and 13% of the cement mass by MHA. After the dosage, the tests were performed on the concrete in its fresh and hardened state: slump test, specific mass, compressive strength (28 days), tensile strength in diametrical compression, water absorption by capillarities, specific mass in the hardened state, modulus of elasticity and morphological evaluation, through the Scanning Electron Microscope (SEM). Checking first the properties of concrete in the fresh state, it is evaluated that the insertion of the waste decreased the consistency and decreases the specific mass, except the concrete for the content of 6% that there was a 10% increase in the specific mass in relation to the concrete reference. Regarding the properties in the hardened state, the replacement by CCM showed an increase specifically in compressive and tensile strength in the 6% content at 28 days around 1% and 9% respectively, occurring a decrease in the contents of 9% and 13%. The results showed that there is a technical feasibility with partial replacement of 6% of MHA in cement, using plasticizer additive to improve workability
Acesso aberto (Open Access)
Ferramenta para mensuração da capacidade tecnológica no segmento de construção de edifícios
(Universidade Federal do Pará, 2022-08-17) SILVA, Horácio Lima da; ISHIHARA, Júnior Hiroyuki; http://lattes.cnpq.br/3498874642887006; https://orcid.org/0000-0002-0081-7913
Technological innovation is essential to enhance the performance of industrial organizations with a view to acquiring competitive advantage, as it adds improvements in products, processes and services. Currently, Industry 4.0 is the most modern synthesis of the accumulation of innovations, representing a new era of industrial production. Despite its importance, civil construction is not yet fully inserted in this new industrial context, especially when considering underdeveloped countries. The building construction subsector, for example, is predominantly characterized by a low technological level when compared to other industries. In this sense, it is extremely important to develop studies that establish an understanding of the aspects that lead to this scenario of low technological level in civil construction. Therefore, this work was based on the theory of accumulation of technological capabilities to develop a tool, called in this work FMCTEED (Tool for Measuring Technological Capability in Building Companies), aiming to trace the technological profile of building construction companies and understand the aspects that need to be enhanced in these organizations to overcome the technological backwardness. This dissertation used bibliographic research, interviews with experts and mathematical modeling as a methodology to build a tool capable of expressing the accumulation of technological capacity in companies in the buildings subsector. In a second step, the model was applied to companies in the buildings subsector to analyze the performance of the tool. As a result, the study showed that the companies object of the study practically do not have ST&I development mechanisms; in addition, the survey revealed a huge gap in industrialization and robotization of processes; there was also a weakness in terms of a collaborative network that includes universities and research centers for the production of technologies that can be incorporated into the production process. Finally, it can be said that FMCTEED was successful in establishing the technological profile of the companies studied and in listing critical points for intervention with a view, for example, to the implementation of innovations.
Acesso aberto (Open Access)
Formulações de argamassas autonivelantes para contrapiso com incorporação parcial de agregado reciclado de concreto
(Universidade Federal do Pará, 2019-01-21) OLIVEIRA, Thais Valadares; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Self-leveling mortar is a material with advantageous characteristics for the industry of civil construction, among them: high flatness, low thickness of the elements that use it, rapid application and short demand of labor for its execution. In order to add knowledge about this material, as well as to make it more sustainable, by incorporating recycled concrete aggregates in its mixture, the present work was proposed. The main objective was to build self-leveling mortars with incorporation of these residues and to characterize them in the fresh state, verifying the technical feasibility of their use. Furthermore, in a complementary manner, it was observed how different combinations of additives may influence the properties of these mortars. Based on the use of a base formulation, available in the literature, eight traces were produced, including four variations of replacement of common sand by recycled aggregate (0%, 25%, 50% and 75%) and two possible combinations of additives, one employing in parallel a superplasticizer additive and a viscosity modifying additive and another in which only one polyfunctional plasticizer additive was applied. Initially, each mixture passed through individual adjustments so as to have adequate consistency, flow time and visual configuration, without demonstrating the occurrence of exudation or segregation. Thereafter, fresh tests were carried out to verify exudation, mass density, incorporated air content and curing time of the mortars. At the end of the research, it was noticed that the incorporation of recycled aggregate in self-leveling mortars could be a technically feasible option, and even advantageous for the mortars formulated with it, considering the evaluated properties, by reducing, among the mixtures with the residue and those ones of reference, the amount of additive employed (up to 0.2%), the exudation (the quantity of water exuded reached 2.04% in a mixture with recycled aggregate and 2.61% in a mixture of reference), the incorporated air content (ranging from 0.17% to 1.34% between traces with and without recycled aggregate) and the mass density (reduced up to 5.5%). Among the combinations of additives, in turn, it was observed that the most satisfactory was the one that employed polyfunctional additive.
Acesso aberto (Open Access)
Gestão de resíduos da construção civil: um estudo de caso em Tucuruí-PA
(Universidade Federal do Pará, 2022-11-17) SOUSA, Fernanda dos Santos; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042; TEIXEIRA, Marcelo Rassy; http://lattes.cnpq.br/8912916360456192
The Civil Construction Industry (CCI) is guilty of impacts on the environment being one of the main sources of pollution today, especially with regard to the generation and disposal of waste in urban centres, this research was developed to diagnose and propose improvements in the management of Construction and Civil Construction Waste (CCW) in a small town, the case study was conducted in the city of Tucuruí-PA, a hub city in the Amazon region. To this end an investigation was conducted through online questionnaires with questions about management and management of CCW and was also performed identification of Irregular Disposal Points (IDP) through georeferencing using the Global Positioning System (GPS) and Qgis 3.16.6 software. After the analysis, we sought to suggest what would be the best improvement strategies for the management of waste from civil construction, through the current diagnosis of the management of CCW in the city. Through this research it was possible to perceive the most relevant points of management difficulty on the part of the Tucuruí Municipal Government (PMT), which are: absence of specific legislation for CCW, lack of environmental education on the subject, absence of supervision, in addition to the lack of management carried out by construction companies operating on construction sites, it was also possible to locate the IDPs and know the destination given to the CCW, in a market practically non-existent and without stimulus. The analyses contained in this diagnosis of the current situation of Civil Construction Waste management will enable actions to be recommended to improve it through public policies in the municipality of Tucuruí-PA, as well as in the region.
Acesso aberto (Open Access)
A influência dos agregados reciclados de resíduos da construção civil nas propriedades do concreto permeável: uma revisão sistemática
(Universidade Federal do Pará, 2023-01-27) OLIVEIRA, Thainá Maria da Costa; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Sustainable development in the civil construction sector has been increasingly promoting the advancement of research on sustainable technologies in order to mitigate the problems caused by this sector. In view of the above, a sustainable measure that aims to reduce the consumption of natural resources and the irregular disposal of waste is the practice of reuse and/or recycling of RCC, and as a solution to flood control, the use of permeable concrete (CPER) is proposed. Due to the lack of standardization and divergence of the procedures determined for the characterization of the CPER with recycled aggregate, it became necessary to analyze the scientific knowledge of this material and demonstrate the feasibility of using RCC in the production of the CPER. In view of the above, this research aims to contribute to the knowledge about the use of recycled aggregates in the production of pervious concrete, through the selection of articles in databases from the last 15 years, in order to evaluate the properties acquired by materials with different types, sizes and contents of recycled aggregates. The present research used the Systematic Literature Review (RSL) as methodology for conducting the study. The articles were collected from the four most prestigious scientific bases for publications on themes related to civil construction. To screen the articles and prepare the RSL, the StArt tool was used, and data extraction from the studies was defined in the research protocol prepared. The results showed that the subject gained more relevance in the year 2016, the Science Direct database presented the highest number of articles, 80% of the works used coarse aggregates in the production of CPER, the percentages of substitution most used among the researches were 100% and 50%. Structural and mixed concrete waste were the most used as recycled aggregates in the production of CPER. It was possible to note great dispersion between the data collected in the surveys and the component materials of the CPER. Moreover, it was found that all types of aggregates met the strength and porosity values determined by the ACI and the permeability met both standards, except for the glass waste. Thus, the application of recycled aggregate in the production of CPER was evaluated as an adequate solution to the problems of irregular waste disposal and shortage of natural aggregates.
Acesso aberto (Open Access)
Influência no comportamento mecânico do concreto com a utilização de microfibras de polipropileno para redução do efeito de retração: um estudo realizado em Belém do Pará
(Universidade Federal do Pará, 2022-10-27) CUNHA, Wictor Alencar; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
Seeking to mitigate the effect of concrete shrinkage, the influence on the mechanical behavior of concrete reinforced with polypropylene microfibers was studied in this study. In the experimental program, 15 (fifteen) study series were produced: one reference without the addition of polypropylene microfiber for each w/c ratio studied, totaling 3 series; and another 12 (twelve) series with the following characteristics: addition of 0.6% and 1.0% of microfiber content varying the length in 12 mm and 25 mm, the w/c ratios being studied with values of 0.45 ; 0.55 and 0.65. Tests were carried out in the fresh state of the concrete to evaluate consistency and workability; and in the hardened state to evaluate compressive strength, flexural traction and modulus of elasticity with age of the specimens at 7 and 28 days; and dimensional variation with age of 48h, 7 and 28 days. The results obtained were studied through analysis of variance (ANOVA) and the Tukey test to determine the statistical significance of the responses found. It was concluded that the optimum content of addition of polypropylene microfiber to concrete was 1.0% with fibers of 12 mm length and w/c ratio=0.55.
Acesso aberto (Open Access)
Modelagem da capacidade de infiltração de diferentes cenários de pavimentos permeáveis na bacia do Una - Belém-PA
(Universidade Federal do Pará, 2023-04-06) PALHETA, João Victor Batista; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Permeable concrete is an important alternative for sustainable construction, being used to preserve water quality and restore soil infiltration properties. To analyze this behavior, a study was conducted to analyze the infiltration capacity of different permeable sidewalk scenarios in the Três de Maio sub-basin located in Belém do Pará using SWMM software. To this end, characteristics were stipulated such as the effect of sidewalk thickness on infiltration rate, base thickness on infiltration rate, the effect of permeable sidewalk area on infiltration rate, and water catchment potential in the proposed scenarios. The scenarios were divided into nine drainage system arrangements, distributed into three thicknesses for the base course (100 mm, 200 mm and 300 mm) and 3 three for the permeable concrete sidewalk reservoir (300 mm, 400 mm and 500 mm). With the insertion of permeable sidewalk it was noticed that all the modeled scenarios obtained significant benefits, however, the application of permeable concrete thickness variation did not obtain significant influence on the infiltration rate keeping its results constant. The use of permeable sidewalk has a great potential for water catchment in all scenarios, showing promise to be applied in areas with a low degree of permeability, especially in the sub-basins that make up the Una basin in Belém do Pará, which suffer from flooding and inundation due to urban sealing and the outdated drainage network.
Acesso aberto (Open Access)
Placas cimentícias produzidas com a incorporação de pérolas de poliestireno expandido (EPS)
(Universidade Federal do Pará, 2020-09-01) SILVA, Max Weverton Moreira da; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
The Internal and External Vertical Painel Systems are the parts of the residential building that limit it vertically and delimit its environments, such as facades and walls or internal partitions. The use of seals with lower density than masonry provides a reduction in the mass of this subsystem, reducing the demand for aggregates and binders, in addition to reducing the load on the structure, which allows for optimization of its design. The objective of this work is to verify the viability of the production of cementitious slabs with the incorporation of expanded polystyrene (EPS) beads for application in internal vertical sealing elements. For this, mortars with a 1: 3 line (cement: sand) were produced, with levels of incorporation of expanded polystyrene of 0%, 10%, 20% and 30% in relation to the total volume of materials. Mortars were characterized in the fresh state, through the determination of mass density and consistency index, and in the hardened state, for knowledge of the density properties in the hardened state, resistance to compression and traction, and modulus of elasticity. After knowing the characteristics of the mortars, cementitious slabs were produced, reproducing the same trace in the specimens. The plates were tested for bulk density, water absorption, water permeability and flexural strength. The results of this work demonstrated that the cementitious slabs with the incorporation of up to 20% of EPS present technical characteristics for application in internal vertical sealing systems.
Acesso aberto (Open Access)
Reação álcali-agregado: potencial reativo dos agregados miúdos provindos das jazidas dos municípios de Ferreira Gomes, Macapá e Porto Grande no estado do Amapá
(Universidade Federal do Pará, 2024-02-29) FIGUEIREDO, Rodrigo Francklin Lopes; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
The concrete is one of the most employed materials in engineering, its performance and durability can be altered by various deterioration processes, making it essential that materials used in its composition be analyzed and suitable for each type of construction. Among these processes, there is the alkali-aggregate reaction (AAR), which is defined as a chemical process that occurs between the alkaline components of cement and certain types of reactive aggregates, which can result in the emergence of expansive products that cause structural damage to concrete (Neville, 1997). The objective of this work is to analyze the reactive potential of fine aggregates, specifically the alkali-reactive potential of 8 sand samples from the main deposits in the municipalities of Ferreira Gomes, Macapá, and Porto Grande in the state of Amapá (AP). The motivation for this research arose due to the lack of data regarding the reactivity of fine aggregates in the state and as a preventive measure against the occurrence of alkali-silica reaction (ASR). For this evaluation, the first test used was the accelerated mortar bar method following NBR 15577 - 4 (ABNT, 2018). In addition to this, the chemical method following NBR 9774 (ABNT, 2008) was employed as an auxiliary, as well as scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS) attached, in order to observe the microstructure of the bars, verify the presence or absence of products that evidence the occurrence of AAR, and through semi-quantitative elemental chemical analysis, identify the substances present in the bars. The results indicated in the accelerated method that the collected samples do not have deleterious potential, as the bars did not reach 0.19% expansion; the highest percentage of expansion was 0.12% in the Translima Deposit (J7), this innocuous behavior was confirmed with the use of the chemical method. Regarding the use of SEM, the formation of the gel related to ASR was not observed. Finally, the mapping of reactive aggregates was carried out, and it was found that the aggregates are innocuous and can be used satisfactorily regarding ASR.
Acesso aberto (Open Access)
Utilização de rejeito de minério do cobre como agregado miúdo na produção de concreto
(Universidade Federal do Pará, 2019-03-29) SOUSA, Douglas Martins; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
A major concern with recent accidents involving tailings dams has again raised the urgent need for mining companies to adapt to the fate of ore tailings generated by their operations. In this context, the reuse of these materials in the construction industry shows itself to be an excellent alternative. In this research, it was evaluated the reuse of copper mining waste as a partial substitute for the small aggregates in the production of conventional concretes, aiming the evaluation of the mechanical performance of the concrete produced with this material, also if it is objective, to obtain a material destination sustainable for this material. Only in the mine where the material was collected, is there about 160 million tons of this material accumulated in the mine tailings basin, which shows that there is a considerable source of this material available for reuse. In the experimental program there were four study series: one reference composed of concrete without the addition of the tailings, and another three with 15%, 30% and 45% of substitution to the small aggregates, besides the use of two water ratios /cement. Fresh tests were carried out to evaluate the influence of the reject on the plastic properties of the concrete, and in the hardened state, test specimens were tested at 07 and 28 days for the axial compressive strength, diametral compression traction, traction in flexion and modulus of elasticity. The results obtained were statistically treated through analysis of variance (ANOVA) and proved for the substitution parameter of reject, there was significance. The results showed that the samples with substitution of tailings obtained good results, significantly increasing both the tensile strength and the compressive strength of the concrete when compared with reference series under the same conditions. Therefore, copper reject shows an excellent potential to be reused in the production of concrete, with respect to its effects on the mechanical properties of the concrete, in addition to achieving a more sustainable destination than today.