Dissertações em Engenharia Civil (Mestrado) - PPGEC/ITEC

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2304

O Mestrado Acadêmico foi aprovado pela CAPES em 1999 e inicou-se em 2001 pertente ao Programa de Pós-Graduação em Engenharia Civil (PPGEC) do Instituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA).

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Acesso aberto (Open Access)
Resíduo da bauxita na produção de agregados graúdos sintéticos para concreto estrutural: análise de durabilidade
(Universidade Federal do Pará, 2022-12-15) MACHADO, Vinícius Costa; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
In the midst of environmental policies, civil construction began to seek alternative materials, such as those arising from industrial waste; and with each passing day this has become more common. This fact is related to issues involving: the high demand for construction materials; the depletion of raw material reserves; the high cost and space of waste storage; and possible risks to public health arising. In the case of industrial waste, mining waste should be highlighted, in particular the bauxite residue (BR) resulting from the Bayer ore refining process, which has already become a promising alternative raw material in several countries, including Brazil for a number of applications. The BR has been studied and used somewhat recently in the production of coarse aggregates for concrete, with success in several studies. However, the information available regarding the use of coarse synthetic aggregates in concrete is mostly linked to its physical-mechanical properties, with a certain lack of data regarding their influence on the durability of structural concrete. The study initially addressed the physical mechanical characteristics and reactive potential by alkali-aggregate reaction (AAR) of 3 coarse synthetic aggregates (AGS 70, AGS 80 and AGS 90), obtained from BR together with silica and clay, based on in the normative requirements required for use in concrete. Soon after, the concrete produced with these aggregates, in total replacement of pebbles, were evaluated regarding their physical-mechanical properties (resistance to axial compression, traction due to diametric compression, modulus of elasticity, water absorption by capillarity) and durability (accelerated carbonation and penetration of chlorides). The results showed that the synthetic BR aggregates were consistent with the technical specifications for use in structural concrete and did not trigger AAR, thus remaining inoculum. The axial compression strength (28 days) reached values between 36-24 MPa; traction and modulus of elasticity showed little variability; capillary absorption was proportional to the increasing linear trend of water absorption by coarse aggregates; highlighting the concretes with AGS 70 and AGS 80 that obtained better performance in the physical-mechanical characteristics analyzed. The carbonation resistance of concretes containing AGS 70 and AGS 80, based on normative references, were classified as low and exceptional respectively. Regarding the penetration of chlorides, they were classified as moderate resistance (with AGS 70 and AGS 80) and low (with AGS 90) according to the methodology used.
Acesso aberto (Open Access)
Determinação do Tempo de Concentração em uma microbacia hidrográfica utilizando traçador salino: estudo de caso da bacia hidrográfica do Igarapé Sapucajuba
(Universidade Federal do Pará, 2019-10-11) MATOS, Thiago Rodrigues de; PENNER, Giovanni Chaves; http://lattes.cnpq.br/3110276957027781; ALMEIDA, Hélio da Silva; http://lattes.cnpq.br/0071472719215354
To determine the time of concentration (tc) of watershed, several practical methods have been developed, which are mostly empirical. However, determining this response time is difficult as these methods are often used indiscriminately through their incorrect application to their validity field. Thus, the present work aimed to determine the time of concentration for the watershed of stream Sapucajuba, from field measurements, with the aid of saline tracer (sodium chloride - NaCl) and by testing 08 empirical methods, which select morphometric characteristics of the watershed, being subsequently compared to the value measured in the field to verify which methods would be more suitable to be applied in the basin. To determine tc in the field, initial tests were carried out to determine some parameters such as test time, instantaneous measurement interval and concentration of the tracer solution. In general, the underestimated methods or the value of the time of concentration, overestimated, thus, a leakage of the water body, being the most suitable methods for tc estimates, those of Come the Chow, DNOS and Kirpich, because it found percentage errors of 9.51, 12.13 and 19.92%, respectively, compared to the time of concentration measured in the field.
Acesso aberto (Open Access)
Compósitos cimentícios reforçados com fibras do epicarpo do coco babaçu para aplicação em placas cimentícias.
(Universidade Federal do Pará, 2022-08-25) ARAÚJO, Myrela Vieira de; SANTANA, Audirene Amorim; http://lattes.cnpq.br/7431678688628387; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
The search for new materials for civil construction based on renewable sources has contributed to sustainable development. Lignocellulosic fibers are possibilities for strengthening cementitious mortars, since they are low cost, easy to reach, and renewable, unlike artificial fibers. However, when added to the cement matrix, they reach low durability and undergo degradation. Thus, the present research aimed to analyze the physical, mechanical, morphological and mineralogical properties of cement composites reinforced with fibers from the epicarp of the babassu coconut of the species Attalea Speciosa Mart. Ex Spreng in 0natura and impregnated in silica fume paste. The composites trace was established through a pilot study, using the trace 1:3:0.62 and addition of 1% of fibers with length ≤ 25 mm. Three families of mortar were molded, the first without the addition of fibers (REF), the second with the addition of in natura fibers (AFST) and the third with the addition of treated fibers (AFCT). The babassu coconut epicarp fibers had a specific mass of 1.398 g/cm³, a moisture content of 6.93% and an average tensile strength of 141.9 MPa. After 28 days of wet curing, the properties of the composites were analyzed, reaching an increase of 46.68% for theflexural tensile strength after the addition of in natura fibers and for composites with treated fibers a decrease of 14.16%. For the apparent density, both AFST and AFCT conditions, there was a decrease in the property and in the water absorption, there was an increase of 8.20% and 11.49%, respectively. In the permeability test, there was no formation of droplets in all samples and the thermometry analysis showed fiber compatibility with the cement. Through the micrographs of the mortars, it was observed in the AFST samples the presence of waxes that offer protection against water penetration, while in the AFCT samples there was a loss of waxes. From the diffractograms, it was verified that the impregnation of the fibers in silica paste caused the loss of calcite and portlandite, producing samples with greater porosity. Thus, the addition of fibers in natura provided improvements in the properties of the composites, but the treatment in silica fume paste caused a decrease in properties, not being suitable for use.
Acesso aberto (Open Access)
Influência da temperatura de síntese do metacaulim para uso em pastas geopoliméricas
(Universidade Federal do Pará, 2022-12-09) BRANDÃO, Luis Felipe Alencar; SILVA, Alisson Clay Rios da; http://lattes.cnpq.br/7389345867032737; https://orcid.org/0000-0001-9186-2287; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357; https://orcid.org/0000-0001-7313-1229
Geopolymers are a type of alkali-activated cement, composed of one or more precursors (sources of aluminosilicates), in general metakaolin, and an alkaline activating solution. This type of cement is known to have low carbon emissions and high initial strength gain, besides being able to incorporate several industrial wastes in its structure and also be compatible for the creation of reinforced concrete or not. Therefore, this work aims to study the influence of kaolin processing temperature for its transformation into metakaolin, in addition to evaluating the best proportion of SiO2/Al2O3 between the range of 3.5, 4 and 4.5 regarding compressive strength. For this purpose, kaolin of commercial origin was used as raw material for the production of the precursor, solutions based on sodium silicate and sodium hydroxide as an alkaline activator. The kaolin was processed at 3 different temperatures (550 °C, 650 °C and 750 °C), originating 3 different precursors, MK- 550, MK-650 and MK-750, respectively. From this, cylindrical specimens were made to evaluate the compressive strength of the geopolymer paste. And by combining with the evaluation of the 3 sio2/Al2O3 contents, 9 analysis points were established. Through diphratometry (XRD), it is possible to notice that there was full amorphization of the kaolin at 750 °C. And when rehearsing the test specimens with cure for 7 days at room temperature, it was found that the best formulation was for SiO2/Al2O3 = 4.0, with 25.2 MPa. After a reduction in the total water content of the system, there was an increase in resistance to 46 MPa at 7 days and when waiting 28 days for the cure of this series, a reduction was noticed to 29 MPa, possibly related to alkali excesses. Further tests show that the water absorption and porosity of the material is 40 % and 48 % respectively. It is concluded that by calcinar kaolin at 750 °C it is possible to produce a precursor for geopolymers of good resistance, being more economical energetically than usual in the literature researched.
Acesso aberto (Open Access)
Avaliação de dano ambiental: aplicação de um índice de qualidade em um vazadouro a céu aberto
(Universidade Federal do Pará, 2022-04-05) CONCEIÇÃO, Mário Marcos Moreira da; PENNER, Giovanni Chaves; http://lattes.cnpq.br/3110276957027781; https://orcid.org/0000-0003-0335-5352; TEIXEIRA, Luiza Carla Girard Mendes; http://lattes.cnpq.br/9773700229115395; https://orcid.org/0000-0002-0204-6825
The objective of this research was the adequacy and application of a waste landfill quality index (IQAR) as a management tool for the open-air dump in the municipality of Castanhal-PA. For this, a socio-environmental diagnosis was carried out in the research area, in the Urban Solid Waste (USW) management and management system in Castanhal-PA and in the recycling companies in the municipality. A simple checklist was applied to identify the potential socioenvironmental damage resulting from the inadequate disposal of USW in the open-air dump, to the secretariats linked to sanitation in the municipality, collectors and the community of the agrovila Boa Vista. To qualitatively and quantitatively assess the environmental damage generated, the Global Damage Index (IGD) was applied. In order to determine the IQAR, the results obtained were analyzed and interpreted, for later framing the open-air spillway under adequate or inadequate conditions. The indices that make up the IQAR refer to the characteristics of the location, infrastructure implemented and operational conditions. According to the data obtained, the secretariats sampled have flaws due to the lack of elaboration, monitoring, evaluation and updating of the municipal Master Plan, which is expressed by the lack of information on issues related to the leak or projects in progress. The data obtained indicated that the Directly Affected Area (ADA) and the limits used for the disposal of MSW correspond to an area of 54 hectares. Irregularities and the lack of technical criteria in the forms of final disposal of USW and tailings at the ADA are the main factors that promote socio-environmental damage. As for the most significant environmental damages in the ADA, according to the sampling of collectors, they refer to the possibility of pollution/contamination of the soil (100%) by the inadequate disposal of waste and tailings from the various commercial and industrial activities of the municipality, burning of waste (64%), deforestation (52%), water contamination (86%) and air pollution (34%). After an analysis carried out in loco, the community Boa Vista was identified as an Area of Direct Influence (AID), approximately 1km from the spillway, the extensions of the water bodies, due to constant problems related to contamination/pollution from the runoff of surface water and groundwater that can take different directions, and the unpleasant odor by the predominant direction of the winds towards that community. The data obtained to identify the socioenvironmental damages in the dump, from the application of the IGD referring to the indicators of the physical environment, indicators of the biotic and abiotic environment and of the operational conditions, indicated that all the items listed suffer damages of direct and indirect order, with emphasis on infrastructure implemented (-0.50), water (-0.51), fauna (-0.63) and flora (-0.59). Thus, the general value of the IGD (-0.44) shows the precarious conditions of all the indicators evaluated, with damages ranging from -0.33 (operating conditions) to -0.63 (fauna). The results obtained with the application of the IQAR for the characterization of the structural, operational aspects of the locational aspects of the Castanhal-PA open-air dump, indicated alarming conditions in all indicators with predominant assessments referring to inadequate, absent or insufficient conditions. According to the methodology of CETESB (2020), with the value of the IQAR (0.4), the open-air dump in Castanhal-PA has inadequate operating conditions. In order to minimize the damages diagnosed, it is necessary, from the beginning, to know the characteristics of the waste produced in that municipality, the gravimetric composition and, as a matter of urgency, an adequate system of final disposal of MSW must be implemented with: licensing of the activity, delimitation of the area, physical fencing with screens, inspection and periodic maintenance of the site and access roads.
Acesso aberto (Open Access)
Influência da substituição parcial do cimento por sílica ativa nas propriedades de argamassas com agregado reciclado de concreto.
(Universidade Federal do Pará, 2023-04-13) CRUZ, Welington de Sousa; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
The main objective of this dissertation is to evaluate the effect of partial replacement of cement by silica fume on the physical-mechanical behavior of coating mortars with recycled concrete aggregate (RCC) and to analyze its environmental impacts, considering CO2 emissions and energy consumption. generated in the production of mortar raw materials. We tried to evaluate the influence of recycled aggregates in proportions of 1:3 and 1:4 (in mass) by partially replacing the natural aggregate with 0%, 30% and 50% RCC, and each of these groups was subdivided with substitutions partial cement by silica fume in the contents of 0%, 5%, 10% and 15%. The results allow concluding that the increase in the recycled aggregate content in the mortars impacts on its rheology and reduces its mechanical properties compared to the reference one, being softened with the incorporation of silica fume. Regarding environmental impacts, cement was the main cause of impacts. Samples R0S15 present the highest cement consumption in both the 1:3 and 1:4 mixes and, therefore, generate greater impacts. However, the impacts generated per unit of resistance show an inverse situation. Therefore, despite generating higher CO2 emissions and energy consumption, their contribution to resistance reflects greater sustainability.
Acesso aberto (Open Access)
Impacto da inércia de seções retangulares e do consumo de fibras na resposta estrutural de vigas contínuas em CRFA solicitadas por carga distribuída: campanha experimental
(Universidade Federal do Pará, 2023-01-25) MONTEIRO, Paulo André dos Santos; MORAES NETO, Bernardo Nunes de; http://lattes.cnpq.br/5790058515094077
In order to play up the proper selection of rectangular section inertia on flexural design of steel fibre reinforced concrete beams, SFRC beams, an experimental campaign has been introduced. Presently, four beams have been tested, where the reference one, with cross section of 150x300 mm2, was in reinforced concrete, RC, and three beams were in SFRC. The rectangular section inertia judgment was on SFRC beams only, where their cross-sections varied in 150x300, 110x400 and 90x500 mm2. The cross-section areas of those beams were constants and their fibre contents were 75, 60 and 45 kg/m3 on concrete volume, respectively. Under those circumstances, the conventional reinforcement arrangements, i.e., steel rebar details, were alternated as well as suppressions were also executed on SFRC beams. Nevertheless, all SFRC beams have carried the reference strength, which meant, the RC beam strength. In addition, it is worth mentioning that all questions called before were carried on continuous beams, where normal and transverse stresses are concomitantly relevant, under uniformly distributed loading. As a conclusion, the results have shown the effectiveness of steel fibres, as a reinforcement alternative, and the advantages of a proper inertia in design issues, warranting the reference strength, even using less reinforcement, both rebars and fibres. Now, concerning to design guidelines, MC10 (2013) proposals have been handled. Herein, applying those letters of support, an interactive methodology was introduced to figure out the flexural strength of RC and SFRC beams, taking, at the same time, all description of reinforcement influence, longitudinal/transverse rebars and fibres. To conclude, in order to improve, in the future, the design of continuous beams uniformly distributed loading, some advices have also been announced.
Acesso aberto (Open Access)
Etiquetagem PBE Edifica em edificação pública com auxílio da tecnologia BIM
(Universidade Federal do Pará, 2019-10-30) ROSA, Rafael Cuimar Corrêa; MAUÉS, Luiz Maurício Furtado; http://lattes.cnpq.br/7497951647889934
Building in a sustainable manner has been a great challenge for construction sector professionals. Labels are one of the tools available to make buildings more efficient in several aspects. Currently, public buildings above 500m2 of constructed area are required to plan and built with energy efficiency level A according to the Brazilian Program for Energy Efficiency - PROCEL, and for this reason, the knowledge of professionals in the area about the parameters of energy efficiency is essential. Thus, the Building Information Modeling technology, BIM, was used to generate the modeling of a public building located at the Federal University of Pará, which received adjustments in the model in order to make it more efficient. The Webprescritivo tool was used to evaluate the current situation and the changes applied in the building, by the prescriptive method, information was entered into the tool and it calculated the efficiency. As a result, it was found that the adjustments made in the model, allowed the building optimization, increasing from C to A its level of energy efficiency. Also, it was found that the use of BIM technology was able to assist in the assessment of the PBE Edifica label through the rapid process of component changes and generation of accurate tables with building data, but further studies and improvements are still needed for better interaction between the tools covered in this research.
Acesso aberto (Open Access)
Impacto do volume de sólidos sedimentáveis no escoamento hidráulico e no custo de manutenção de canal de drenagem
(Universidade Federal do Pará, 2021-12-13) REBÊLO, Marcos Vinicius da Silva; PEREIRA, José Almir Rodrigues; http://lattes.cnpq.br/9918600634569244
The Impact of sedimentable solids volume on hydraulic flow and drainage channel maintenance Cost. The study area was the Tamandaré drainage basin, located in the central region of the city of Belém/PA. The research was developed in three stages. Initially, the situation of the Tamandaré Channel was analyzed, investigating the main information related to the management of rainwater in the studied basin, obtaining topographic, hydrological and drainage system data. Then, the main factors and contributors to sediment accumulation in the channel were surveyed. Finally, in the Storm Water Management Model 5.0 software, a simulation was performed with the ideal operation of the drainage channel without the occurrence of solids and precipitation to serve as a parameter for further simulation with the occurrence of solids. The subsequent step simulated scenarios with sedimentation of solids in the macrodrainage structure, considering: a) rainfall, lasting 1.5 h, 3 h, 6 h and 12 h and b) 10%, 20% and 30% of the Channel obstructed by sediments, resulting in 15 hydrodynamic simulations. The last stage of the research presented the Hydrodynamic impacts, demonstrating that the capacity of the Tamandaré channel is sufficient to drain the precipitated volumes with 10% of its volume committed to solids. However, with 20% of the solids occupying the channel bed, flooding occurs in the scenarios of 1.5 h, 3 h, and 6 h of rainfall, only in the 12 h simulation there was no flooding because, with this storm scenario, the precipitation was more distributed, favoring channel flow. The scenario of 30% of the channel occupied with solids resulted in flooding in all precipitation scenarios, the highest flood magnitude occurred during rainfall of 1.5 h reaching 3.44 m, generating a water level of up to 1.07 m above ground on the roads close to the Tamandaré channel. The cost analysis showed that with the current spending scenario it would be possible to keep the Channel free of solids, as long as this cleaning took place on a daily basis in the indicated volumes equivalent to 2 tipper buckets 2 times a day, however, no cleaning in some days such as Sundays and holidays made the accumulation of waste a reality in the canal. Thus, it is necessary to complement the cleaning of the channel for the total removal of the sediments in this drainage channel in the densely occupied urban area of the municipality of Belém.
Acesso aberto (Open Access)
Estudo de ligante geopolimérico obtido a partir de metacaulim e escória granulada de alto forno
(Universidade Federal do Pará, 2022-12-06) MORAES, Mario Henrique Moreira de; SILVA, Alisson Clay Rios da; http://lattes.cnpq.br/7389345867032737; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
The need for alternative materials to replace Portland cement is a contemporary discussion. Those new and alternative materials must have a sustainable character and good durability to supply the demand of the civil construction sector and mitigate the environmental crises caused by the industry, such as the high emission rate of CO2. In this context, geopolymeric binders appear as materials produced by different solid precursors in contact with an alkaline activator, with zero CO2 emission and mechanical properties and durability compatible or superior to that of Portland cement. Thus, this study aimed to evaluate the geopolymeric binder obtained from the combination of metakaolin (MK) and ground granulated blast furnace slag (GGBFS) with three different molar concentrations of sodium hydroxide (8, 10, and 12 M) for the alkaline activator. Dosages were established from the partial mass substitution of MK by GGBFS, coded as G0 (100% MK 0% EAF), G20 (80% MK 20% EAF), and G40 (60% MK 40% EAF). XRD, XRF, and SEM analyses were conducted for solid precursors. Geopolymer pastes properties were evaluated in the fresh state regarding setting time and in the hardened state based on physical tests, average compressive strength, and fracture morphology. Results showed that the MK and the GGBFS have adequate reactivity and chemical composition for the geopolymer synthesis, with the presence of calcium in the GGBFS actively contributing to the reduction of the setting time and gain of mechanical resistance of the dosages. As for the hardened state, higher levels of water absorption are intrinsically related to a decrease in mechanical strength, with fracture analysis revealing the presence of pores and micropores that favor the propagation of cracks. Statistical analysis found that the interaction between the analyzed factors significantly influenced the properties of the materials, with 85.35% (R2 = 0.8535) of the model being able to explain the variation in compressive strength of geopolymers as a function of the factors used in the regression, limited to the chosen range of variables. The G40M12 formulation showed the highest compressive strength value (38.08 MPa) and the ideal synthesis parameters defined were the rotational frequency at 150 RPM, a partial replacement of MK by GGBFS of 40%, and the NaOH concentration of 12 M. Finally, from the correlation of the evaluated characteristics, the developed geopolymeric binders showed technological potential as alternative and sustainable materials, with properties comparable to those of Portland cement.
Acesso aberto (Open Access)
Redes neurais recorrentes para modelagem chuva-vazão de pequenas bacias hidrográficas amazônicas
(Universidade Federal do Pará, 2022-04-29) MENDONÇA, Leonardo Melo de; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
Rainfall-runoff models can help the management of water resources, especially in the Amazon, a region marked by the low density of hydrological monitoring, and thus benefit the multiple uses of water and the adequate use of water resources. This work seeks to simulate daily streamflows of five small catchments in the Amazon, through the Autoregressive Recurrent Nonlinear Neural Network with Exogenous Variable (RNN-NARX). Daily rainfall and streamflow data were used for simulation. The cross-correlation and partial auto-correlation functions helped to determine lagged data, relevant inputs, with a significance level of 5%. In addition, the Levenberg-Marquardt error backpropagation algorithm was used for supervised training of RNN-NARX. Five statistical indices and Garson's relative contribution of each input variable were also used to evaluate the simulations. Thus, the simulated flows were classified between unsatisfactory and very good, in addition to showing a general tendency to underestimate floods. The autoregressive characteristic of each catchment is fundamental for better results, quality attributed to the water storage capacity. A plausible explanation for the main sources of uncertainty is due to the spatial variability of precipitation between monitoring stations and the precipitations occurring in the catchment, meteorological anomalies and discretization aspects. The sensitivity analysis of the models against different training intervals showed that the implementation of 2 years, for the supervised training of the RNN-NARX, is sufficient to obtain efficient simulations in four of the five small Amazon catchment analyzed.
Acesso aberto (Open Access)
Gestão dos resíduos de construção civil procedentes de pequenas construções no Município de Belém- Pa
(Universidade Federal do Pará, 2019-02-26) LEITE, João Alex Garcia; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357; https://orcid.org/0000-0001-7313-1229
The construction industry is one of the most important sectors to the economic development of Brazil. However, it also causes some of the greatest environmental impacts mainly due to the improper disposal of construction waste (CW) in natural areas and large urban centers. The issue of CW in Belém includes the problematic due to the absence of the Municipal Construction Waste Management Plan (PMGRCC). Of particular note is the daily construction waste generated and improperly disposed of by small companies and individuals, which is very common in Belém. The main objective of this dissertation is to study the current CW management system for small companies and individuals, with the purpose of improving the treatment processes for CW improperly disposed of by small-scale construction sites in the city of Belém. The specific aims include: identification of those involved in the generation, transportation, and final disposal of CW. The research is based on an exploratory, explanatory, qualitative approach and will be restricted to the Municipality of Belém. It will involve field visits to take photographic records, interviews with those involved in the process, and analysis of data from the Municipal Sanitation Department (SESAN) and the Municipal Solid Waste Department (DRES). It is hoped that the results of this research will help facilitate the introduction of an efficient management process for the control, handling, and final disposal of CW in Belém.
Acesso aberto (Open Access)
Ocorrência de fármacos e desreguladores endócrinos em resíduos da estação de tratamento de água do Bolonha, Belém - PA
(Universidade Federal do Pará, 2022-05-10) FERREIRA, Clara Cardoso; TEIXEIRA, Luiza Carla Girard Mendes; http://lattes.cnpq.br/9773700229115395; https://orcid.org/0000-0002-0204-6825
Nowadays, the microcontaminants presence in water has been attracting the attention from scientific Community, since these compounds are found in small concentrations (ng/L or µg/L) and can cause adverse effects on the aquatic ecosystem and human health. Therefore, the presente study aimed to investigate the occurrence of 24 drugs and endocrine disruptors in water washing from Bolonha’s Water Treatment Plant (WTP) filters, located in Belém city, Northern region of Brazil. The correlation of these microcontaminants with physicochemical and biological characteristics investigated in the studied matrix was also evaluated. For the research, six sampling campaigns were carried out during the rainy season and six sampling campaigns in the dry season during the filter chamber washing. The compounds determination was carried out by solid phase extraction and chromatography coupled to mass spectrometry, gas chromatography for Ibuprofen, Paracetamol, 4-Nonylphenol, 4-Octylphenol, Bisphenol A, Gemfibrozil, Estrone, Estradiol, Etinilestradiol, Estriol, and in liquid phase for the Other compounds. The Losartana (5,5 to 738,7 ng/L) and Bisphenol A (20,9 to 518,9 ng/L) were detected in high concentrations and in all samples collected, being the compounds with the highest frequency of occurrence in matrix. The 4-Octyphenol (13,5 to 51 ng/L) and Loratadine (3,4 to 24,6 ng/L) showed low concentrations, however they were present in 11 of 12 samples showing a high frequency of occurrence in washing water. Caffeine (1090.2 ng/L) had the highest concentration among the contaminants, however, it was only detected in one sample. Multivariate analyzes showed that drugs and endocrine disruptors were more positively related to each other and to turbidity during the rainy season. It is worth noting that the compounds that were most strongly correlated with each other and with the physicochemical and biological variables of the washing water, in both periods, were 4-Octylphenol, Bisphenol A, Losartan and Loratadine. The study also suggests that the concentration of microcontaminants decreased with decreasing turbidity. In general, the results confirmed the influence of precipitation on the variables and indicated the presence of domestic sewage discharges in the supply system of the Bologna complex, especially as it is located in an area with intense anthropic activity.
Acesso aberto (Open Access)
Concreto reforçado com fibras de bambu (Dendrocalamus Giganteus)
(Universidade Federal do Pará, 2019-11-14) FERNANDES, Robson da Silva; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357; https://orcid.org/0000-0001-7313-1229
Vegetable fibers appear as an alternative to manufacture structural elements in relation to metal and synthetic fibers that have high costs, also causing pollution to the environment due to their manufacturing process. This study analyzes the results of mechanical tests of a fiber reinforced concrete of bamboo bark (Dendrocalamus Giganteus), for use in cementitious plates, obtained experimentally in cylindrical and prismatic specimens according to ABNT standards and international recommendations. Composite traces were determined by means of a pilot study, 1: 2.12: 2.88: 0.58 using the CP-IV pozzolanic cement. The experimental program consisted of a 25 MPa Fck reference concrete and three dosages corresponding to 0.5%, 1.0% and 1.5% by volume of bamboo fiber to the concrete mass, forming four dosages in total. After curing, according to NBR 5738 (2003), prismatic specimens were tested for flexural tensile strength according to NBR 12142 (2010) / JSCE-SF4 (1984) and cylindrical specimens to evaluate the strength. from CRB to axial compression, according to NBR 5739 (2018), to diametric compression tensile, according to NBR 7222 (2011) and static modulus of elasticity, according to NBR 8522 (2008). In the axial compression test the presence of bamboo did not provide an increase of resistance in relation to the reference concrete. However for the tensile and flexural strength, the mixing with the addition of bamboo fiber generated a strength gain of 7% and 9%, respectively, compared to the concrete without addition. It can be concluded that insertion of fiber from bamboo bark increases the tensile strength of the composite.
Acesso aberto (Open Access)
Avaliação da presença de antiflamatórios não esteroides no sistema de abastecimento de água Bolonha Belém/PA
(Universidade Federal do Pará, 2022-04-12) RIBEIRO, Caroline Mascarenhas; TEIXEIRA, Luiza Carla Girard Mendes; http://lattes.cnpq.br/9773700229115395; https://orcid.org/0000-0002-0204-6825
The present study aimed to investigate the occurrence of non-steroidal antiinflammatory drugs - NSAIDs in the Bolonha Complex, Belém-Pa, from water samples collected in the Bolonha Reservoir (raw water) and after the filtration and disinfection of the ETA Bolonha, in addition to verifying possible relationships between the NSAIDs in the study and the water quality parameters. The determination of NSAIDs was based on the solid phase extraction method, on GC-MS (Gas Chromatography coupled to mass spectrometry) for the identification of the compounds Ibuprofen (IBU) and Paracetamol (PAR), and LCMS/MS (Chromatography Liquid coupled to sequential mass spectrometry) to obtain Naproxen (NAP) and Diclofenac (DFC). The results obtained indicated the presence of the four drugs PAR, IBU, NAP and DFC in the Bolonha Complex. At point AB, the first three drugs, respectively, had an annual mean of 3.7 ng/L, 9.1 ng/L and 351.8 ng/L. At point AF, the same drugs obtained, in the same order, annual mean concentrations of 14 ng/L, 231.2 ng/L and 1932.2 ng/L. At point AT, only IBU and DFC were detected, with annual averages of 0.9 and 35.9 ng/L, respectively. It was found that the main step responsible for the elimination of drugs was chlorination, especially in the rainy season, equivalent to an annual removal efficiency of 100% in the cases of PAR and NAP, and 94%, referring to the IBU. In the correlations, no strong relationship was identified between the drugs detected in the raw (AB), filtered (AF) and treated (AT) water points. At Point AB, the approximation of the NAP with the pH color, apparent color, total iron, turbidity and E-coli variables stands out. At point AF, the same drug showed a correlation with the apparent color in the rainy season, however in the dry season it did not show strong correlations with any of the variables analyzed. At point AT, the DFC stood out with the approximation of the pH, turbidity and alkalinity variables. In general, the assessment of the presence of NSAIDs proved to be important for a better understanding of the issue of microcontaminants in the Amazon and, in addition, confirmed the hypothesis of the presence of NSAIDs in different parts of the ETA Bolonha, which may be related to the discharge of untreated sewage from the neighboring population
Acesso aberto (Open Access)
Eficácia da ABNT NBR 6118 (2014) na previsão da carga última de pilares curtos/esbeltos em concreto armado sujeito à flexão composta normal.
(Universidade Federal do Pará, 2019-11-27) LEITE, Jonas dos Santos; MORAES NETO, Bernardo Nunes de; http://lattes.cnpq.br/5790058515094077
Once the short/slender reinforced concrete columns theory has been slightly presented in the national technical/scientific literature, it could be considered as a research goal working up this kind of publication. However, bringing about the accuracy judgment of the ABNT NBR 6118 (2014) design guidelines to predict the load-carrying capacity for short/slender reinforced concrete columns under combined axial load and bending has been the outstanding inquiry target. Wherefore, both the simplest proposals as well as the accurate one have been introduced and taken stock herein. It is worth underscore that two concepts have marked the simplest proposals, namely, standard-column methods with approximate curvature (AC method) and approximate stiffness (AS method). Thus, the interaction diagram concepts together with load-moment curves (P-M), which were addressed in a linear (L) and nonlinear (NL, geometrical issue) way, had accounted for the accurate method. To vouch for the scrutiny undertook before, 17 experimental investigations, which had added up to 320 reinforced concrete columns, composed the database (DB) handled currently. From then on, the performance index ξ has been embraced and assessed by means of descriptive statistic thought, where ξ = Pexp/Ptheo (Pexp = experimental failure load recorded in the DB and Ptheo = theoretical/predicted failure load). Ended up the quest, the effectiveness of whole design guidelines to predict the failure load for short/slender reinforced concrete columns from DB was bearing out by the results had brought forth herein. Notwithstanding the previous positive outcome, it was also pointed out that predicting the failure load of slender columns with slenderness ratio high than 35 the P-M (L) proposal had been in an unsafe condition.
Acesso aberto (Open Access)
Análise da tendência de precipitação e vazão na bacia hidrográfica do Rio Amazonas
(Universidade Federal do Pará, 2022-02-24) DIAS, Luanna Costa; FERNANDES, Lindemberg Lima; http://lattes.cnpq.br/4641468846318922
Studying rainfall and flow trends is important to understand hydrological variability and to determine what has influenced increases or decays. The present study analyzes the trends of the space-time annual series of precipitation (total annual precipitation and maximum annual precipitation) and flow (averages, maximums and minimums) in the Amazon River Basin through non-parametric Mann-Kendall and Sen's tests. Slope for five different periods (1975-2014, 1980-2014, 1985-2014, 1995-2014 and 2000-2014). The results indicate that the series of average flows are increasing in the Amazon Basin for all analyzed periods. In the sub-basins of the right bank of the Amazon River, Tapajós and Madeira, the most recent period (2000-2014) registered the greatest trends of increase in the average annual flow from 1998 (year of strong El Niño) and that reached the largest values already observed. In the maximum flow series, the Óbidos station had an increasing rate of increase for the five periods analyzed for extreme flood events, which directly affect the population residing in these areas. Mean flow decay trends were found at six stations in the Tapajós and Madeira sub-basins. As for precipitation, there are significant trends of increase and decay distributed in several distinct regions of the basin. The stations with the highest positive precipitation trends had a significant increase since 1997, reaching the highest peaks in 2013. The comparison of the magnitude of the trends by the Sen's Slope test shows that there is a behavior of increasing flow rates in the entire Amazon basin and in terms of precipitation there are areas of increase and decrease, that is, precipitation is not the only variable that influences the flows of the Amazon River basin.
Acesso aberto (Open Access)
Eficácia das fibras de aço no reforço ao cisalhamento de vigas de concreto armado sem estribos: investigação experimental
(Universidade Federal do Pará, 2019-11-27) MAUÉS, Kássio Anderson Castro; MORAES NETO, Bernardo Nunes de; http://lattes.cnpq.br/5790058515094077
Several research papers have been dedicated to the investigation of the behaviour of steel fibre reinforced concrete (SFRC) under several types of forces. Due to its mechanical property to transfer forces through cracks, it has been observed that SFRC presents substantial contribution to shear resistence. The present paper investigates the effects of steel fibres on the shear reinforcement of concrete beams without stirrups under four-point bending tests. For that purpose, five beams were cast and tested. The dimensions of the beams were 150 mm×300 mm×2700 mm, with 1.54% and 0.16% of tension and compression longitudinal reinforcement ratios, respectively. Two of the beams were manufactured as references, that is, without fibres, with one of them having conventional transversal reinforcement with stirrups and the other with no reinforcement to shear. The other three beams were reinforced with steel fibres only in the shear span in the proportions of 45 kg/m³, 60 kg/m³ and 75 kg/m³ of the concrete volume, which represent 0.6%, 0.8% and 1.0%, respectively. Concrete strength of 30 MPa was used for all the specimens. In addition to the typical characterization of concrete and steel used in this research, flexural test was performed on SFRC in order to obtain the residual stress response of the material, whic h is paramount for the evaluation of the strength of the beam. From the experimental results, it could be concluded that steel fibres exhibited satisfatory performance under shear forces in the cases of higher fibre content, for which a change in failure mode was observed: from shear failure to flexural failure. Furthermore, for the three fibre contents used, the possibility for partial or total replacement of the transversal reinforcement was confirmed. Additionally, it was demonstrated that the use of steel fibres in the content of 60 kg/m³ and 75 kg/m³ allows for the reduction of the longitudinal tension reinforcement to attain flexural strength similar to that of the reference beam with stirrups
Acesso aberto (Open Access)
Influência de inundações no valor de aluguel de imóveis comerciais em Belém, Brasil
(Universidade Federal do Pará, 2021-09-27) LIMA, Gabriel Villas Boas de Amorim; NEVES, Renato Martins das; http://lattes.cnpq.br/6538317425557058
The real estate appraisal might be driven by externalities, such as surrounding, locational, and natural attributes. In residential property studies, flood influence in housing valuation is a well-known subject; however, there is a gap in commercial real estate. Thus, this thesis sought to assess if flood influences commercial property rents in Belém-PA, Northern Brazil, a city where flood-prone areas concentrate the most significant retail activity. To this, OLS regression models predicted the impact of flood-prone-zone locations on the marginal rents in a 586 commercial property database. The results revealed that highly flood-prone zones reduce commercial rents by 9.78% rather than in no flood-prone ones. It decreased 3.26% in rent values between each flood-prone zone (low, medium, and high). When moderated by the property frontage, the impact of flood-prone zone diminished because more prominent facades induced more consumer attraction, thus demand. The sensitive analysis revealed an accuracy in predicting commercial rents ranging from 13 to 36 reais per square meter. The scientific-added value concerns the novelty approach in evaluating flood influence in commercial property rents in emerging country scenarios. Besides, it assists investors by using the econometric model as a decision-maker support tool to acquire commercial real estate
Acesso aberto (Open Access)
Emissões de gases de efeito estufa na disposição final de resíduos sólidos urbanos no Estado do Pará.
(Universidade Federal do Pará, 2023-04-20) ALMEIDA, Fernando Felipe Soares; PEREIRA, José Almir Rodrigues; http://lattes.cnpq.br/9918600634569244
The growing generation of Urban Solid Waste in the world and the consequent emission of Greenhouse Gases - GHG originated from the final disposal activity has influenced waste management and challenges municipal administrations to adopt waste management procedures and methods that minimize the GHG emission in this activity. This study examines GHG emissions resulting from the final disposal of urban solid waste in the state of Pará. The research was qualitative-quantitative with exploratory and descriptive objectives, focusing on the solid waste sector in the state of Pará. The activities were divided into four stages, verifying the contribution of the solid waste sector to GHG emissions (Stage 1), observing the situation of the final disposal of solid waste in the municipalities of the state (Stage 2), estimating the generation of GHG emissions from the final disposal of solid waste (Stage 3), and analyzing opportunities to reduce GHG emissions in the solid waste sector (Stage 4). The results of the research show that Pará is the state with the highest GHG emissions in Brazil (447,927,368 tons of CO2e). Although the solid waste sector accounts for only 1% of GHG emissions, it was found that 138 out of 144 municipalities in Pará still send their solid waste to open dumps and controlled landfills. Considering the total amount of solid waste collected in the municipalities of Pará in 2021 (1,016,874.64 tons), the estimated GHG emissions were 952,901.86 tons of CO2e, indicating an impact on the environment. The research showed the need for the environmentally appropriate final disposal of solid waste as an alternative to reducing GHG emissions in the state of Pará.