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)
Ação do vento na estabilidade global efeitos de segunda ordem em estruturas de concreto armado na cidade de Belém-PA
(Universidade Federal do Pará, 2018-02-23) MEDEIROS, José Odilon Barros de; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
Due to the exponential growth of urban populations, the need for space for housing has grown significantly. To meet these demands, increasingly tall and slender buildings are designed, always aiming at the need to reduce costs and raise profitable margin by the construction companies. New materials and methods of structural analysis are created and improved so that maximum performance and structural safety are extracted at the lowest cost. Thus, this dissertation aims to contribute to the studies concerning the analysis of global stability and evaluation of the effects of 2nd order in the structures, from the comparative analysis of stability parameters, with the premises described in NBR 6118 (2014). In relation to the ultimate limit state, the following coefficients were evaluated: α and γz - suggested by NBR 6118 (2014), as well as FAVt and 𝑅𝑀2𝑀1 - obtained by the CAD/TQS System. With regard to the service limit state, the results concerning the horizontal displacements at the top of the buildings were analyzed and compared with the normative limits. For this, computational modeling was performed representing nine distinct fictitious structures submitted to the actions of the usual project loads on residential buildings, according to the aspects of NBR 6120 (1980), besides the evaluation of the influence of the consideration of the wind loads in the mentioned models structures. As for the development of the structures, usual techniques of discretization were employed, using the finite element method, through the CAD/TQS program. From the results obtained, it was observed that in the higher structures the parameters related to the ELU and ELS exceeded the normative limits, and that the fact regarding the lack of consideration of the wind action in the structures can significantly compromise the behavior and structural safety, since the calculated 1st and 2nd order final efforts can be up to 41% lower in relation to the efforts calculated by applying the criteria described in NBR 6123 (1988), in turn causing undersized structures and consequently, leading such structures to results catastrophic, such as ruin through progressive collapse.
Acesso aberto (Open Access)
Análise da manutenção de pavimentos urbanos: uma proposta de implantação de um sistema de gerência de pavimentos
(Universidade Federal do Pará, 2017-09-19) BARRA, Renata Brabo Mascarenhas; NEVES, Renato Martins das; http://lattes.cnpq.br/6538317425557058; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
The absence of urban planning and management is the factor that most contributes to driving municipalities to a precarious stage of their infrastructure. The management of the maintenance of the urban pavements is important for a good management of the public services offered by a municipal body, being a great challenge to its managers. The development of an internal management system better incorporates the needs of the agency responsible for interventions in the road network, besides, it aims to generate economy and improve the quality of the services provided. The urban road network is one of the main components of the municipal infrastructure system, and yet the concern of public managers with the systematization of procedures for the management of this road system is small. In view of the above, this research has the objective of proposing the implementation of an Urban Pavement Management System to a public Road Works Department. As a research strategy, the case study was adopted, since a field research was carried out by means of the application of a structured questionnaire, analyzing in depth the research focus. In addition to the bibliographic review stage, the study comprised the execution of three phases, the first one referring to the presentation of the idea (motivation) and the initial diagnosis of the focus of the research, the second phase corresponded to the software development stage the elaboration Of the Urban Pavement Management System - SGPU and the third phase corresponded to the implementation and use of the developed system. The main results are: the creation of a computational tool capable of generating an inventory of the municipal road network, generating support reports for decision making considering the type of existing pavement, type of last maintenance done on the road, Services per neighborhood of the analyzed region, the condition of the subgrade and its drainage system, the type of roadway covering and its Pavement Condition Index. These reports provide senior management with the foundation needed to plan the short, medium and long term actions correctly, increasing efficiency and assertiveness in meeting the demands. Finally, it was concluded that the developed system met the general objective of the research, generating in a satisfactory way the inventory of the routes of the analyzed region, aggregating information for management decision-making in the organ, in addition, this research becomes important for the environment For its innovative character in the analyzed region, consolidating itself as one of the references regarding the management of maintenance of urban pavements in public agencies.
Acesso aberto (Open Access)
Análise das causas de aditivos de custo e de prazo em obras públicas de instituições federais de ensino
(Universidade Federal do Pará, 2019-03-19) ALVARENGA, Felipe Campos; MAUÉS, Luiz Maurício Furtado; http://lattes.cnpq.br/7497951647889934
Completing works within the cost and schedule stipulated in the planning phase is a major problem faced by managers in the construction industry. With this, several studies have been carried out around the world to identify the main reasons that lead to noncompliance with the works at the time and cost initially established. The present study aims to analyze the contractual additions made in public works of the Federal Institutions of Education (IFEs) and the main reasons that led to their conclusion. To achieve this goal, statistical tools were used to compare the cost and time changes between the country regions. The data of this work includes public construction projects divided in all the 5 regions of the Country, filtered from the database of the Ministry of Education. A diagnosis was made showing the percentage of additives among the regions and the main justifications of the same ones indicated in a sampling in this database. Statistical techniques such as the Kruskall-Wallis Analysis of Variance and the Mann-Whitney U-Test were used for data analysis and inference. As results, the differences in the distribution of time and cost additives were statistically significant among the regions, with the South and Central-West regions presenting the greatest differences and the North, Northeast and Southeast regions with a statistically similar behavior among them. Of the 2178 projects collected, 69.05% had additives of term and 61.89% of cost. The main factors that affect time and cost of the projects were the inclusions and / or modifications of design and the additions of services. The ways to reduce the incidence of overruns point to the use of Building Information Modeling (BIM) technology, lean construction and greater experience in the management of works.
Acesso aberto (Open Access)
Análise de risco de cumprimento de prazo de construção comercial
(Universidade Federal do Pará, 2018-05-25) BATISTA, Amanda Cremilda Lima; MAUÉS, Luiz Maurício Furtado; http://lattes.cnpq.br/7497951647889934; DUARTE, André Augusto Azevedo Montenegro; http://lattes.cnpq.br/1135221873341973
Civil construction is characterized by its complexity and uncertainty, because its processes occur simultaneously and interdependently, inserted in a dynamic, non-linear and unpredictable environment. It is necessary throughout the life cycle an evaluation and management of the risk factors, thus enabling the elaboration of prevention strategies and opportunities. Therefore, this research had as objective the probabilistic evaluation of the risks in the terms of a vertical construction project, located in the city of Belém / Pa. The strategic objective of the stakeholders was the completion of the work in the 15-month period and a forecast of direct and indirect costs of R $ 8,808,614.04. In this way, the probability of the project to occur within the desired period (15 months) was evaluated through two PERT / CPM networks, called scenario 01 and scenario 02. Given that scenario 01 was developed considering the 15-month period and scenario 02 developed according to the unit composition tables of term and costs, which is called the pessimistic scenario of the work. Thus, the results of the evaluation showed that the project had a 76.79% probability of occurring in 22 months, with a possible budget increase of 35.18%, close to R $ 11,907,293.46. Therefore, the PERT / CPM methodology is satisfactory, since the objectives of this research were achieved. However, the network is incompatible with the contextual reality of the project, since construction projects have other interacting variables that influence time and costs and are impossible to evaluate with the PERT / CPM network.
Acesso aberto (Open Access)
Análise experimental de pisos mistos de madeira e concreto de pós-reativos (CPR)
(Universidade Federal do Pará, 2016-12-20) BRITTO, Raimundo Angelo de Lima; VELOSO, Luís Augusto Conte Mendes; http://lattes.cnpq.br/9476653308517248
Mixed timber and concrete structures have long been part of the constructive context around the world, and are mainly used for the recovery of old wooden floors in single or multi-family dwellings, mainly in European and North American countries, are used Also in structures of bridges and walkways in the open air since the concrete plate protects the wood from the elements, solar radiation among others. Several factors contribute to the use of this type of structure in homes, among them the following: the cost much cheaper than the conventional construction in reinforced concrete, the architectural lightness of the arrangement, with the apparent varnished wood and painted slabs, Providing a very good finish, thermal and acoustic insulation if we take as a reference the only wooden floors. This work highlights the use of wood from reforestation in Brazil, being chosen for its beauty and resistance to Tectona Grandis (TECA), and for the slab that compose the table we chose a concrete of post reactive, where some aggregates are by-products of the industries of Paper and glass. The geometry drawn for slab was outlined in search of having the best structural arrangement, combined with the good architectural effect. The expressions for calculating the mixed wood-concrete floor are based on the equilibrium equations and the precepts of EUROCODE 5, the parameters for verification and safety follow the precepts of NBR 7190/97, NBR 6118/14 of EUROCODE 5 itself. The results show that there are significant differences between the analytical and finite element methods (SAP 2000), the results between these models had significant differences, as far as the experimental model, the measurements performed showed a much higher stiffness than those presented In the two models mentioned above. We conclude that the elasticity moduli of the materials and the sliding modulus must be tested in order to be close to experimental results. The results obtained in the experimental model showed us excellent rigidity, the safety factors regarding the EL and final use were met the final cost of assembly even with the use of the post-reactive concrete was lower than the cost of a conventional structure , Thus we can denote that the concrete-wood structures present great conditions of use in constructions and reforms, being of the utmost importance the incentive and the continuity of this constructive technique.
Acesso aberto (Open Access)
Análise mecânica e microestrutural da interação do bambu com o concreto
(Universidade Federal do Pará, 2018-04-03) SALGADO NETO, Francisco de Souza; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
Several materials have been used in construction, steel and concrete being the most used. However, such materials present high production costs and generate great impacts to the environment. The purpose of this research is to analyze the interaction between concrete and bamboo of the species Dendrocalamus giganteus as well as to verify the potential of the annealed wire as a reinforcement of bond between the above-mentioned materials, justified by the search for alternative and renewable materials concomitantly with the defense of sustainability. The experimental schedule is divided into 3 stages: morphological, physical and mechanical characterization of bamboo; concrete dosing; and study of bamboo concrete interaction, analyzing the use of two types of wrapping wire on the bamboo surface as a mechanism of bond reinforcement: single spiral and double spiral, from the determination of the bond strength at 28 days for each case, of the load x displacement behavior and the microstructural analysis of the concrete bamboo interaction. The fixed factors were: compressive strength of the concrete (28 MPa), 200 mm is the length of bonded interface, bamboo sticks with rectangular section of 20 mm x 10 mm. All the results obtained were analyzed by statistical tests and it was verified that the presence of the node and the use of wire increases the bond strength by 42% and at least 25%, respectively.
Acesso aberto (Open Access)
Análise não linear de vigas de concreto armado com fibras de aço
(Universidade Federal do Pará, 2019-08-20) FIGUEIRA, Fábio Rogério Mendonça; OLIVEIRA, Dênio Ramam Carvalho de; http://lattes.cnpq.br/1324105476558186
In the present work, a proposal is presented for the calculation of the ultimate strength, MR, of reinforced concrete beams with steel fibers (CRFA), considering the non-linear behavior of this material. For this purpose, the proposals of five normative recommendations, ACI 544.4R-88 (1988), RILEM TC 162-TDF (2002), CECS 38 (2004), CEB-FIP (2010) and DAfStb (2010). To evaluate the proposal, a database with 42 beams was used, which broke the bending. The performance of the proposal is judged as a function of the parameter ⅄ = Mexp / Mteo, which defines the ratio between the experimental (BD) and theoretical resistances. It should be noted that the parameter ⅄ is evaluated in terms of accuracy, dispersion, safety and classified according to an adaptation of Demerit Points Classification - DPC. Finally, we present the nonlinear simulation of the moment-curvature relationship with the help of the SAP 2000 software, applying the equations proposed by RILEM TC 162- TDF (200) and the equations developed by Moraes Neto (2013) for the residual resistance of this material.
Acesso aberto (Open Access)
Análise para implementação de usina para reciclagem de resíduos da construção civil em Tucuruí-Pa
(Universidade Federal do Pará, 2018-05-25) SIQUEIRA, Rafaela Ribeiro; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
Civil Construction Waste (RCC), as they are known, is generated in construction, remodeling, repairs, excavation of land for civil works and demolitions. In this context, the work was carried out in the municipality of Tucuruí in the State of Pará, with the objective of evaluating the economic feasibility of implementing a RCC Recycling Plant. Research was carried out to diagnose the management of RCCs by the public authority of the city and it was verified that management does not take place efficiently. Thus, through the collection of information, it was possible to estimate the generation of RCC in Tucuruí, the daily generation is around 1.566,33 m3. Thus, to carry out the economic feasibility analysis, the annual gross revenue was determined, where the costs of implementation of the project and operation were calculated, and from the calculated net values, the cash flow from the Recycling Plant and the investment analysis method was calculated using the Net Present Value (NPV), Internal Rate of Return (IRR) Payback (PB) and the Profitability Index (IL) for the time horizon of 20 years, not considering the inflation. In order to define the Minimum Attractiveness Rate (TMA), a rate of 12% was adopted, since it is close to the SELIC rate for the year 2017, 12.25%. The results show that there is economic and financial feasibility in the implementation of this investment, thus, NPV R $ 1,148,946.06 positive, IRR 14%, PB will be completed in 4.2 years and IL 1.71, demonstrating the economic viability of the project. The estimation of three different scenarios was also done, with 5% increase in gross revenue, 5% increase in expenses and increase in TMA by 15%, thus concluding attractive results for the investment.
Acesso aberto (Open Access)
Análise quantitativa da degradação de fachadas em revestimento cerâmico: estudo de caso em edifícios de Belém– PA
(Universidade Federal do Pará, 2018-06-15) SANTOS NETTO, Clementino José dos; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
This study approaches the collect and identification of pathological manifestations in the façades of five buildings, with ceramic coating system (SRC), in the Metropolitan Region of Belém / PA, using Silva 's adapted damage quantification model (2014). The proposed methodology consists of a systematization of the inspection process, with identification, mapping and quantification of the pathological manifestations in the façades of the buildings, applying the Damage Factor (FD) as a way to evaluate the degradation behavior as a function of influence factors such as type of manifestation, age and solar orientation of the facades, also analyzing agents of degradation such as directed rain, solar radiation and humidity. Subsequently, the Combined Damage Factor (FDC) was applied, which assigns weighting indices to the FD, related to the repair cost of each observed anomaly. Analyzing the results, it was verified that the pathological manifestation stain (MA) on the ceramic coating was the one that presented the highest percentage of occurrence, that is, greater degraded area, among the types of anomalies observed. In addition, this manifestation presented high values of FDC in all cardinal orientations and expressive values of this index of degradation, both in façades under 20 years and in those with more than 20 years. These results are directly influenced by the extremely aggressive climate of the region, which presents constant rains and high humidity (up to 95%), favoring the propagation of this anomaly (staining) already in the first ages of the building, since the façades (10 and 16 years old) already had considerable degradation rates of this pathological manifestation. The orientation that presented the highest degradation factor was the South direction (FDTotal=9.42%), influenced directly by the phenomenon of directed rainfall, which presents its highest Directed Rain Index (ICD) in the North direction, affecting the facades oriented in the South direction. After the application of FDC, the pathological manifestation of ceramic detachment / displacement (DC) presented the highest degradation index (FDCMédio=39.22%), due to its high restoration cost, when compared to the repair value of the other anomalies evaluated. By means of the histograms of FDTotal and FDCTotal, a characteristic exponential curve was observed that shows a decrease in the frequency of occurrence as the value of the degradation index increases. This characteristic curve was also observed in Silva (2014) and Souza (2016).
Acesso aberto (Open Access)
Aplicando concreto de elevada resistência reforçado com fibras de aço na supressão do reforço convencional de vigas em concreto armado de resistência normal
(Universidade Federal do Pará, 2020-01-14) SOUSA, Elielson Oliveira de; MORAES NETO, Bernardo Nunes de; http://lattes.cnpq.br/5790058515094077
High strength steel fiber reinforced concrete (HS-SFRC) used as suppression of conventional reinforcement normal strength reinforced concrete beams (NS-RC) has been in the current experimental research. Five 150x300x2700 mm³ size beams were prepared and submitted to four point bending test until failure. The beam reference have been produced without steel fibers (fc = 30.0 MPa), with longitudinal reinforcement ratio (ρl,t = 0.91%), and transverse reinforcement (ρw = 0.11%), representative of practice applications. Four other HS-SFRC beams were produced with fc = 60.0 MPa, ρl,t = 0.39% (≈ 60.0% suppression relative to reference beam), ρw = 0.0 % (100.0% suppression) and fiber consume (Cf) alternating in 45,0,60,0, 75,0 and 90,0 kg/m³. The behavior beams was analyzed from load-displacement and moment-curvature relations. The viability to design HS-SFRC beams with suppression conventional reinforcements was verified based on these results and material characterization tests, exposing equivalent mechanical behavior and some cases higher that of NS-RC beams.
Acesso aberto (Open Access)
Aprendizagem Baseada em Problemas (ABP): identificação das dificuldades docentes para a utilização do método no curso de Engenharia Civil.
(Universidade Federal do Pará, 2019-08-28) SILVA, Sidnei Silva e; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179; NEVES, Renato Martins das; http://lattes.cnpq.br/6538317425557058
The technical training of engineering teachers brings with it difficulty in mediating in an educational process way of building knowledge, which negatively influences student training. To minimize such effects, we used the Problem Based Learning (PBL) as an alternative. Therefore, this paper aims to present the difficulties identified in the teacher's perception for the use of the method in the civil engineering course through the construction of an implementation proposal in two disciplines in a public university of Marabá. The research is characterized as action research and was developed in eleven cycles proposed in the disciplines. These problems were built based on the contents offered for these subjects and a technical visit to a teaching institution that uses PBL as a curricular basis. Besides, we used observations of similar studies developed on the use of the PBL method. The results demonstrate the feasibility of using the technique, shown by the good acceptance of both the teacher and the students involved in the research. Besides that, we observed which the students have gotten excellent performance at the end of each discipline. However, some difficulties were found: the cultural elements, the curriculum, and the lack of some teaching skills as factors that can hinder the use of the PBL either by the student or by the teacher himself. From these results we concluded that the studies demonstrate the feasibility of using the method, however, essential elements present in the educational process would need to be enhanced so that the PBL could be fully used within the institution, such as teacher training, or curriculum-related issues could contribute to the development of the topic addressed in this study.
Acesso aberto (Open Access)
Argamassa autonivelante com adição mineral (fíler) de resíduo de beneficiamento de mármore e granito.
(Universidade Federal do Pará, 2019-02-04) CHAVES, Patrícia da Silva; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
The process of processing marble and granite rocks generates solid waste along its production chain. These residues have environmental impact potential when not properly managed. The waste produced in the polishing phase of marble and granite slabs can be incorporated into the construction industry as an alternative material for the production of concrete and mortar, contributing to technical performance, economic and environmental viability. In this aspect, this work aims to characterize the marble and granite beneficiation residue (RBMG), in its natural state, and uses it as a self-leveling mortar addition to promote cohesion, similar to the viscosity modifying additive (VMA). For this, a reference mortar was produced, one with addition of RBMG and one with addition of VMA. Where, first, the rheological behavior of the pastes and mortars was analyzed. Then, the mechanical properties, durability and microstructural properties of self-leveling mortars were measured. The results show that the RBMG has no pozzolanic potential. The mortar with RBMG presented optimized mechanical properties and durability in relation to the reference mortar, and similar to the mortar with VMA. The microstructural assay demonstrated that RBMG promoted pore refinement of the cementitious structure, probably due to the granular variation of the particles of the residue, providing greater compactness with the optimization of grain packing. It is concluded that the RBMG can be used as an alternative material to replace the VMA, which is an expensive and difficult to reach product in Belém/PA.
Acesso aberto (Open Access)
Avaliação da durabilidade de concretos produzidos com agregado miúdo reciclado de cerâmica vermelha
(Universidade Federal do Pará, 2016-02-05) MORAES, Ruan Fabrício Gonçalves; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
The generation of waste from civil construction (WCC) in Brazil and in the world are of great proportions. However, its reuse does not occur in the same proportions that are generated by construction, is added to this, the need to find solutions for the landfilling of these wastes, unsustainable consumption of natural resources, where deposits already present signals aggregate shortage. Therefore, the use of red ceramic as recycled aggregate, reduces costs for the production of concrete, brings awareness of environmental cooperation and sustainability. In this scenario, the literature is still scarce in relation to the concrete durability properties for this kind of aggregate. Thus, this study aimed to improve and disseminate knowledge about these waste in construction. To this end, mixtures were made with water / cement ratio of 0.45; 0.55 and 0.65, where the aggregate has been replaced by natural fine ceramic aggregate in 0%, 12.5% and 25%, each percentage was subjected to pre-wetting rate of 40%, 60% and 80%. Subsequently, the durability of concrete produced with fine ceramic aggregate (FCA) was evaluated through capillary absorption, carbonation, electrical resistivity and chloride ion penetration. With the results obtained it can be concluded that the slump test was satisfactory in most mixtures, with respect to durability, in general, all mixtures with ceramic recycled aggregate had higher durability than the reference, especially in mixtures with 25% AMC. Pre-wetting rates were effective in most mixtures, showing satisfactory influence on the final results in all tests. So it managed to show great feasibility of using this waste in concrete, improving their performance.
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)
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)
Avaliação dos métodos normativos para previsão da resistência à punção de lajes sem armadura de cisalhamento e com conectores de aço
(Universidade Federal do Pará, 2016-06-06) PEREIRA FILHO, Manoel José Mangabeira; FERREIRA, Maurício de Pina; http://lattes.cnpq.br/4242041552985485
This work presents an evaluation of the code provisions of various standards for the punching shear failure load on slab-column connections without shear reinforcement and reinforced with steel connectors. The code provisions evaluated are the ACI 3118 (2014), Eurocode 2 (2004), AC Eurocode 2 (2010), UK NA (2004), DIN NA (2011), EHE (2008), NBR 6118 (2014), ETA 12 / 5404 (2012), an adaptation of the ETA proposed by MUTTONI and BUJNAK (2012) and the fib Model Code 2010 (2011). These code recommendations are evaluated for accuracy, safety and economy through 340 test results in flat slabs without shear reinforcement and 140 results flat slabs reinforced with various types of steel connectors arranged in two databases, and all slabs had centered load. In both databases the performance of recommendations was evaluated from a statistical analysis, dispersion analysis of the results and penalized according to the "Demeter Points Classification" (DPC). In addition to the database with slabs without shear reinforcement analysis, in order to assess the reason for the dispersion of code provisions observed the influence of various parameters (fc, ρ, d, u0/d) in code provisions of punching shear resistance load. For the database with results of slabs reinforced with connectors, beyond the initial analysis, the database was divided into groups according to the failure modes of slab. In all groups was carried out the evaluation of equations for each mode of breakage by means of a statistical analysis, dispersion penalty and analysis of results using the "Demeter Points Classification" (DPC). In all groups were assessed the influence of various parameters in the provisions.
Acesso aberto (Open Access)
Compósitos cimentícios reforçados com fibras de curauá (Ananas erectifolius) impregnadas com sílica ativa
(Universidade Federal do Pará, 2019-02-01) PINTO, Renata Godinho; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
Vegetal fibers are an alternative for reinforcement in cementitious mortars, unlike the synthetic fibers, they are renewable, biodegradable and low cost. The great limitation of these composites concerns the low durability of the fibers inserted in the cementitious matrix. Therefore, the present research aim to analyze the properties of reinforced mortars with curaua fibers previously impregnated with silica fume. The mix design ratio of the composites was determined with a pilot study. The composites were prepared with mix design ratio 1:3:0.61 and with addition of 2% fibers with 25 mm length. Six families were molded using CP-IV cement and CP-II E. The properties of the composites were verified at 28 days and after natural aging at 180 and 270 days. The characteristics of the curaua fiber used were: density of 1.33 g/cm³, tensile strength of 422.89 MPa and modulus of elasticity of 28.83 GPa. For compressive strength, the composites fibers previous treatment provided a better result than that obtained for mortars with natural fibers. For the tensile strength, inclusion of fibers provided the desired reinforcement improving this property in 45 %. The modulus of elasticity indicated that the addition of the fibers reduced the stiffness of the material. For flexural strength the composite AFCS:IV showed a 57.95 % increase compared to the reference, but it was identified with the natural aging the decrease of the resistance for composites with untreated fibers. The proposed treatment was effective to preserve the toughness of the composites after natural aging. Due to the composites X-ray diffraction, it was verified that the previous treatment of the fibers was effective in limiting the formation of the portlandite in the matrix. This corroborates with micrographs of the mortars, where degradation signals were identified in composites with untreated fibers, while the previously treated fibers remained intact even after natural aging. Thus, it can be considered that the impregnation of the fibers with silica fume improved the properties of the composites and increased the durability of the curaua fibers.
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)
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)
O custo de oportunidade do atraso de empreendimentos imobiliários na ótica do empreendedor: estudo de caso em uma construtora de Belém
(Universidade Federal do Pará, 2016-09-14) TOMÁS, Luciana Mendonça; DUARTE, André Augusto Azevedo Montenegro; http://lattes.cnpq.br/1135221873341973
In a real estate project, even if numerous considerations are made to achieve financial, operational, and consequently success, there are many factors that alter planning and that mainly impact the completion of the project, causing measurable losses, such as failure to comply with Budget, and others difficult to measure, such as the breakdown of the company's prestige in the market. The objective of this work is to measure the cost of the delay of the works to the one who undertakes, based on what economic science characterizes and denominates the opportunity cost, which, applied in this work, will have as a metric the sum of five components/costs: 1) maintenance of the construction site; 2) maintenance of head office; 3) readjustment of the value of the supplys; 4) delayed receipt of funds related to the value of property financing amount; and 5) the detrimental of the company's image, some of which are not measured or even perceived by the entrepreneur, who could avoid them or minimize them if their works are delivered within the scheduled deadlines. Data were collected from thirty (30) works of a large construction company in the city of Belém-PA, which identified a modal delay of almost 22 months. The opportunity cost of the delay in the present study reached a total value of R$ 20,732,963.98, or a basic unit cost of opportunity of R$ 44.68/m² of real global area, that is, the delay, In this case study, corresponds to almost 5% of the cost of construction, proving to be an important and significant component, and should be considered when feasibility studies of real estate projects and management/management of works.