Navegando por CNPq "CNPQ::ENGENHARIAS::ENGENHARIA CIVIL::CONSTRUCAO CIVIL::MATERIAIS E COMPONENTES DE CONSTRUCAO"

Agora exibindo 1 - 20 de 37

Acesso aberto (Open Access)
Análise da adição de resíduos siderúrgicos em matrizes cimentícias para concreto massa
(Universidade Federal do Pará, 2021-12-17) BONFIM, Francirene Pereira; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
During the steel production process, industrial waste is generated, including granulated blast furnace slag and balloon powder, generated in the pig iron production stage; and electric arc furnace dust, obtained in the production stage of the steelworks. In the northern region, the highlight in steel production is SINOBRAS - Siderúrgica Norte Brasil SA, located in the municipality of Marabá-PA, which also experiences the problem of waste disposal, and therefore has been supporting partnerships with educational institutions in the region for expansion of destination alternatives. Thus, this research aims to evaluate the influence of waste from the SINOBRAS industry, granulated blast furnace slag (GBFS), balloon powder (BP) and electric arc furnace dust (EAFD) in cementitious matrices, predicting applications in mass concrete for dams . The research methodology was carried out in two stages, the first being directed towards the study of waste, analyzing its physicochemical and mineralogical characteristics, the pozzolanicity potential according to ABNT NBR 12653:2015, and classification according to the type of solid waste according to ABNT NBR 10004:2004. The second stage of the methodology comprised the analysis of cement matrices composed of the residues, combined with GBFS (GBFS70+BP30; GBFS50+EAFD50), in order to increase the potential performance of the properties verified for mass concrete, with compressive strength tests being carried out, setting times, heat of hydration and alkali-aggregate reaction. It was concluded in the residue study stage that BP and EAFD did not present pozzolanic properties, indicating that they are not interesting for applications of cementitious materials. As for the classification, the GBFS and the BP were classified as class IIA waste - non-hazardous and non-inert, while the EAFD was classified as class I - hazardous. In the second stage of the study, the EAFD combined with the GBFS showed pozzolanicity and the BP, even after combination, remained non-pozzolanic. Evaluating the combined cementitious matrices, the (GBFS50+EAFD50) obtained satisfactory results in all properties, since it promoted a reduction of heat of hydration by 7% and, consequently, an increase in setting times (about 6 hours), and mitigation of expansion reactions, in aggregates gravel and sand by 49%. and 75% respectively. Therefore, the use of the matrix GBFS50+EAFD50, in the studied content, can be a technically viable alternative for applications in mass concrete for dams, being necessary, however, to advance in the research, aiming to produce the concrete traces composed by the matrix combined (GBFS50+EAFD50).
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 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)
Argamassa autonivelante para contrapiso: efeito do tipo de cimento no comportamento físico-mecânico
(Universidade Federal do Pará, 2020-04-24) ALVES, Brenda Maiara Oliveira; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Self-leveling mortar (SLM) is inserted in the construction market as an innovative product due to its special properties when compared to conventional mortars due to the filling of empty spaces and self-compacting only under the effect of gravity, the ability to flow and level without the occurrence of segregation. The use of CP V – ARI cement is common for its production, since its high fineness favors the fluidity of the material and for providing fast hardening, fundamental characteristics that must be considered in self-leveling mortars (SLM’s). However, the rare availability of this type of cement becomes a limiting factor for its applicability in the region. Therefore, the objective of this research is to develop the study of SLM dosage for screed, adapting it to local materials that favor its design and evaluating its influence on rheological and mechanical characteristics. For the production of these mortars, we used the adaptation by Lopes et al. (2018) of Tutikian's methodology (2004) for self-compacting concrete (CAA), using fines in partial replacement of cement, adopting as controllable factors the type of cement (CP I, CP II-E, CP IV and CP V-ARI) and the type of mineral addition (silica fume and metakaolin). For the characterization of SLM in the fresh state, the mini slump, mini V-funnel, flow retention, mass density and incorporated air content, determination of exudation and healing time tests were performed. In the hardened state, the mechanical resistance to compression and traction in flexion and the retraction of these materials were verified, since it is one of the main pathologies of SLM. Analyzing the results obtained, it was observed that the surface area of the tested cements was the factor that most influenced the performance of the produced mortars, where cements with larger surface areas needed more additive to achieve fresh properties and had the highest rates of retraction. Mineral additions contributed to the cohesion of mortars and reduced shrinkage in mixtures with contents of up to 25% metakaolin and 15% silica fume.
Acesso aberto (Open Access)
Avaliação da durabilidade de concretos produzidos com agregados graúdos reciclados provenientes de cerâmicas vermelhas com diferentes taxas de pré-saturação
(Universidade Federal do Pará, 2013-09-05) REIS, Felipe José Losada; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
The amount of waste generated by the construction industry has been calling attention lately due to the size with which acts as the environmental impact of using non-renewable natural sources materials and increasing the amounts of waste produced by the urban environment. In Brazil, this estimate is around 90,000 tons generated per day. The proposed use of aggregate from CW ( construction waste ) as part of structural concrete becomes even more interesting from the moment we are seeking a reduction in costs for the production of concrete , carrying environmentalist mentality when sparing use of natural resources which some are already starting to run out. Banks of sand and pebble sources begin to fade due to the wide use of these aggregates in the concrete produced in Belém and inland cities in the state of Pará. The need for new sources of aggregates makes us seek in construction waste likely sources of aggregates responding in a similar fashion to natural. Considering this proposal, this dissertation evaluated the durability of concrete produced with the addition of ceramic CW through trials of water absorption by capillarity, carbonation, chloride ion penetration and electrical resistivity. To that end, we replaced the natural coarse aggregate by ceramic coarse aggregate by 50%, where this percentage of recycled aggregate was subjected to the rates of pre - saturation of 60 %, 80 % and 100 %. According to the results it can be seen that the presence of RCCA (recycled ceramic coarse aggregate), regardless of the degree of pre- saturation was significant in all the results, the fact that the concrete while leaving more susceptible to loss of durability, it showed a pattern of behavior in relation to the reference mixtures. The closest matches conventional concrete mixtures were made by containing pre- saturated with water at a rate of 80 % ceramic aggregates.
Acesso aberto (Open Access)
Avaliação da influência de sistemas de proteção na permeabilidade de água em placas cimentícias com incorporação de perolas de poliestireno expandido
(Universidade Federal do Pará, 2025-04-24) GOMES, Saulo de Almada; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Water is one of the main elements responsible for the emergence and propagation of pathological events in coatings. Its permeated presence compromises the protective capacity, as well as directly influences durability, and can accelerate the deterioration of mortars, impairing their useful life. It is known that the use of surface protection instruments (painting system) and the use of waterproofing additives in the production of mortar coatings directly influence the protection against water permeability. Within this aspect, this study aimed to evaluate the degree of influence of protection systems for cement boards with the incorporation of Expanded Polystyrene (EPS). EPS was used in the cement board as a partial replacement for sand, in a volume of 20%. Two types of painting systems were evaluated, one for indoor environments and the other for outdoor environments, in addition to a type of waterproofing water-repellent additive, which was applied to the mortar mixture. This evaluation was carried out using two methods that analyze the permeability of mortar coatings: the Karsten tube test (pipe method) and the permeability test of ABNT NBR 15498/2021, which deals with the requirements for using cement boards. The mechanical properties of the mortars and boards were also characterized. The results of this work demonstrated that the protection systems evaluated caused different effects on the permeability of the boards. The waterproofing additive did not significantly influence the permeability of the panels, only the physical characteristics, with greater emphasis on the mass density and water absorption properties. The painting systems positively influenced the waterproofing capacity of the panels, with the external painting system being more efficient. Regarding the permeability assessment techniques, the Karsten tube showed great variability in the results, demonstrating that this technique is more sensitive to the conditioning variables. And, in the permeability test of NBR 15498, all panels passed the use requirement.
Acesso aberto (Open Access)
Avaliação de diferentes tratamentos de base aplicados sobre alvenaria de bloco cerâmico na aderência da argamassa: estudo de caso
(Universidade Federal do Pará, 2011-10-28) SILVA, Cecília Rodrigues da; PAES, Isaura Nazaré Lobato; http://lattes.cnpq.br/3432832117667434
This paper discusses, in a scientific way, the experimental study conducted to investigate the mechanism of adhesion of the mortar coating applied over masonry of ceramic blocks with different basic treatments, namely: (reference 1:3, cement and sand in volume - no cure, 1:3, cement and sand by volume - with healing, 1:3 + SBR additive, cement and sand by volume - no cure, 1:3 + SBR additive, cement and sand by volume - with healing). We adopted three different ages (7, 28 and 120 days) in order to verify the evolution of adhesion over time, both assessments being made on site (in situ) and additional tests in the laboratory. The determination of the tensile bond strength of mortar was facing as a parameter normative NBR 13528 (ABNT, 1995) and the results were subjected to statistical analysis of variance. Were also analyzed aspects related to the influence of both the pore structure of the plaster as the porous substrate adherence, through the techniques of mercury intrusion porosimetry, porosimetry by desorption of water vapor, scanning electron microscopy (SEM) and X-ray diffraction Based on the results obtained showed that the basic treatment, the continuous process of healing the lining damp and age are significant factors in bond strength as well, if you choose to use conventional Chapisco (1:3, cement: damp sand by volume), it becomes importantel the continuous process of healing (for a minimum of 48 hours). In case you choose to use the additive Chapisco, this should not be subjected to excessive moisture (moist cure).
Acesso aberto (Open Access)
Avaliação do emprego de agregado miúdo reciclado na produção de peças pré-moldadas para pavimentação tipo “paver”
(Universidade Federal do Pará, 2021-02-05) VIEIRA, Marília de Oliveira; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
Acesso aberto (Open Access)
Avaliação do uso de lodos de estação de tratamento de água como matéria-prima na confecção de tijolos cerâmicos: estudo de caso - ETA Bolonha
(Universidade Federal do Pará, 2009-06-26) MULLER, Elzelis de Aguiar; LIMA, Alberto Carlos de Melo; http://lattes.cnpq.br/0524669127885256; MACHADO, Luiza Carla Girard Teixeira; http://lattes.cnpq.br/9773700229115395
This study aimed to evaluate the possibility of incorporating the sludge in the water treatment station of Bolonha (RMB), in the manufacture of ceramic bricks for use in construction. Two units of flow of mud (UDL) were established and operationalized in the ETA Bolonha. Before the preparation of ceramic bricks, the mud flows were ETA Bologna in UDL's that were equipped with open collar, and then were characterized physically and mineralogically. The sludge was added to the ceramic body of a local industry for the production of bricks. Various proportions of silt and clay mixture were tested in order to find the appropriate proportion to the production of ceramic bricks (10%, 12% and 20% of sludge in the ceramic body ETA). Laboratory tests were conducted to assess its strength, water absorption, an appropriate size and visual appearance. It was not possible to incorporation of 20% of mud to ceramic body due to the high plasticity and the difficulty of manufacture of ceramic bricks, however, the proportions of 10% and 12% of sludge from ETA were the ones that had better results on the parameters of resistance, indicating that the ceramic bricks can be produced with the incorporation of up to 12% of sludge from ETA.
Acesso aberto (Open Access)
Captura de carbono em placas de concreto permeável
(Universidade Federal do Pará, 2020-06-12) SANTOS, Caio José Bastos Marques; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
The production of cement has an impact on the environment from the release of co2 where carbon dioxide acts directly on the phenomenon of "greenhouse effect". Although cement production generates high rates of carbon dioxide, cement hydration products have the ability to reabsorb carbon dioxide from a physical-chemical phenomenon called carbonation. This research related this physical-chemical phenomenon to a material considered sustainable, such as permeable concrete. This type of concrete can be used on non-reinforced floors. The research focuses on analyzing the ability to capture co2in permeable concrete slabs. As for carbonation, mixtures produced with two granulometric bands of pebble and CP II F agglomerate with a/c ratios of 0.33 and 0.37 were analyzed in protected and unprotected environments, and in an accelerated environment in a co2 chamber. A chemical phenolphthalein indicator was used to assess the occurrence of carbonation in five ages of reading and image analysis software to study the carbonated surfaces. The material showed satisfactory results in terms of mechanical, water and carbonation depth parameters, having reabsorbed the atmosphere gas from the cement paste that surrounds the aggregate grains of the material's granular skeleton.
Acesso aberto (Open Access)
Cisalhamento em elementos de concreto armado com estribos desconectados
(Universidade Federal do Pará, 2017-04-07) TAPAJÓS, Luamim Sales; FERREIRA, Maurício de Pina; http://lattes.cnpq.br/4242041552985485
The use of shear reinforcement can improve shear strength and ductility in reinforced concrete elements. However, depending on the type of reinforcement and the type of construction and solicitation thereof, there may be conflict between the longitudinal and transverse bars. To solve this problem, some researchers have used unconnected shear reinforcements, which are positioned between the longitudinal bars. In addition to avoiding conflict with longitudinal reinforcement, the use of this type of reinforcement can still increase the productivity at the job site, since this type of reinforcement can be prefabricated. However, the use of unconnected shear reinforcement is still limited by the lack of design recommendations supporting their use, as well as there are few experimental studies on the subject. Therefore, this work presents a type of unconnected shear reinforcement, tested in an experimental program and compared with other types of reinforcement. In total, the experimental program involved the testing of 9 reinforced concrete wide beams, where the main variables were the type and rate of reinforcement. In addition to the tests on the beams, tests were carried out on reduced specimens by the push-off test. As results, graphs of displacements, deformations in the flexural and shear reinforcement and in the concrete, cracking maps, surfaces and rupture mode are presented, as well as the last loads observed in the tests with the theoretical loads estimated by different normative recommendations. As the main conclusions, it was observed that the unconnected stirrups can have the same performance in comparison with shear reinforcements with connected anchorage, as well the use of a complementary reinforcement to the W stirrup can improve the shear resistance of a reinforced concrete beam and avoid delamination.
Acesso aberto (Open Access)
Comportamento de argamassas de revestimento quanto à retração, fissuração e mecanismo de descolamento em substratos de concreto
(Universidade Federal do Pará, 2013-10-22) LIRA, Mariana Domingues von Paumgartten; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
This research aims to evaluate the retraction, by the mortar superficial movement, occurrence of cracking and detachment of the mortar. Were choosed two types of substrate, one with a 30 Mpa resistance and other with 40 MPa resistance, also were used two types of mortar, one with additive and other lime based, two thicknesses of coating layer, from 15 mm and 30 mm, and was simulated the exposure condition that the region has.For this, tests were performed to characterize the mortar in the fresh state (consistency, water retention, air entrainment and mass density) and in the hardened state (compressive strength, tensile strength in bending, specific gravity, water absorption, voids and density). After preparation of the samples for evaluation, were taken the measures of superficial movement of the mortar for 28 days and the occurrence of cracks and detachment, as well as the verification of the bond strength of the coating and also the loss of water by evaporation of mortars. As a result of this research, it was observed that the variation of the resistance of the substrate analysis not showed a significant difference in the shrinkage, as well as the thickness of the layer to some series. It was also found that the type of mortar, or the material composition, has a direct influence on retraction. With regard to water loss by evaporation from the mortar, it can be seen that the additive achieved greater success in water retention materials. In the test of bond strength, was found that the most significant influence was in relation to the composition of the mortars and that they had values above the minimum allowed by regulatory norm.
Acesso aberto (Open Access)
Contribuição para o desenvolvimento de compósito cimento-madeira com materiais da região amazônica
(Universidade Federal do Pará, 2005-06) FONSECA, Fábio de Oliveira; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
This work intends to propose an application for tropical wood waste from wood industry as saw dust; from the region of Belem, in the fabrication of wood-cement composite. Due to the natural chemical incompatibility between wood and cement, this procedure results in a set retarding effect, with wood specie depending intensity. This by-effect can be beaten by using a procedure like additives, wood mineralization, accelerated carbonation and others. Analysis were made with axial compression strength at 28 days age data, for mortars made with 2, 3.5 and 5% wood content in mass; using cements type CP I and CP II; with and without Calcium Clorets-based set accelerator additive. Then, obtained data were statistically analyzed for evaluation on wood content and additive use over mechanical resistance. Most of existing researches uses reforesting species, being the tropical ones almost never studied. So, this work represents a pioneer effort in developing a cement-bonded wood composite with our regionally available materials and residues.
Acesso aberto (Open Access)
Desenvolvimento de um software com interface gráfica para análise e verificação de pontes ferroviárias em concreto armado
(Universidade Federal do Pará, 2010-03-05) QUEIROZ, Rafael Leite de; SOUZA, Remo Magalhães de; http://lattes.cnpq.br/1995895693959225
Development of software with graphical interface for analysis and verification of railway reinforced concrete bridges. The work described here is the development of software capable to do structural analysis with emphasis on bridges. More attention is given to the analysis of railway bridges and the automatic generation of live load in accordance with the vehicles and trains-types user defined by. The software called BridgeLab Laboratory (Bridges) is able to do analysis of extreme importance with respect to the design and verification of civil structures. These analysis are: static analysis, pseudo-dynamic analysis, modal analysis and dynamic analysis. The code at BridgeLab was written in MATLAB® platform, due to some advantages of the language resulting in a shorter time of rogramming. The analyzes performed by the program are based on the direct stiffness method and use finite element of space frame which presents six degrees of freedom per node. In addition to performing the analyzes, BridgeLab performs the structural elements verification from the results of efforts obtained in each analysis according to the Brazilian standards, including verification of fatigue damages that is also verified according to the CEB. The verification is done in an integrated way through the SecLab (Sections Lab). After analysis the visualization results, stress diagrams, deformed configurations and modal shapes are done in the BridgeLab interface itself. The visualization of the deformed configurations of the structure and its modal forms can be done as a bar model or as extruded solids, considering the geometry of the cross section of the elements.
Acesso aberto (Open Access)
Desenvolvimento de uma estrutura sanduíche de base polimérica, produzida com resíduos das indústrias de mineração e metalurgia, para aplicação como painel divisório de ambientes internos na construção civil
(Universidade Federal do Pará, 2016-07-05) MIRANDA, Rossana Martins; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
The rechearch proposed to use solid wastes from kaolin and bauxite mining and metallurgical regional industries in a composite of sandwich structure to apply as internal divider panel environments. The blade was of unsaturated polyester matrix, double jute fabric and, kaolin waste (20 wt% polyester) and, the core, of polyurethane expansive and red mud (bauxite waste at process to get alumina), from 0 to 50 wt% PU (increasing by 10 to 10 wt%), in a total of 6 different treatments). The tests carried out were: blade density (ASTM C271/271M – 11), sandwich structure bulk density apparent, sandwich structure porosity, tensile test on the blade (ASTM D5083-10), flatwise tensile test on sandwich structure (ASTM C297/C297M - 04), edgewise compressive test on sandwich structure (ASTM C364/C364M–07), flatwise compressive test on sandwich structure (ASTM C297/C297M - 04), 3-point flexural test on sandwich structure (ASTM D7250/D7250M – 06 e ASTM C393/C393M – 11), Charpy impact test on sandwich structure (ASTM D6110 – 10), flammability test on blade and on sandwich structure (UL 94 - 96) and sound transmission loss test on sandwich structure (ISO 140-3:1995 - E). The results indicated that the choise of polymeric matrices was suitable to reduce weight of such structure mainly the use of a PU expansive. Increasing red mud not contributed to significant increase of sandwich structure bulk density apparent. Kaolin waste reinforcement increased resistance to blade on tensile test. Red mud reinforcement reduced sandwich structure resistance on flatwise tensile, flexural and impact tests. Increasing of red mud didn’t influenced sandwich structure edgewise compressive and flatwise compressive tests but, but it´s use at this sandwich structure, decreased their resistance at the first test and increased at the second test. The PU high flammability was delayed for being cloistered by two blades of polyester and kaolin, proving flame retardant property of kaolin waste. And about sound transmission loss test, the increase of red mud increased that until 20% concentration, after this, stabilized at 25 dB (STC) until 50% red mud. The composite, as a whole, presented feature of a sandwich structure, with a low density core, contributing to reduce structure weight and with higher resistant blades, providing it the desired structural feature to be a divider indoor panel.
Acesso aberto (Open Access)
Diagnóstico de reutilização e reciclagem de resíduos sólidos de construção civil pelas cooperativas de reciclagem no município de Belém-PA
(Universidade Federal do Pará, 2019-07-05) ALMEIDA, Ana Victoria da Costa; MAUÉS, Luiz Maurício Furtado; http://lattes.cnpq.br/7497951647889934
The Civil Construction sector is one of the most important segments of the world industry, being also the one that consumes the most natural resources, and therefore generates a large amount of solid waste. Construction Waste (RCC) is considered inert, but can cause problems when not properly disposed of. When we talk about RCC, we have CONAMA Resolution 307 stating that all municipalities must give RCC’s an environmentally sound destination in order to effectively reduce the environmental impacts generated by this type of waste. Within this context the present study made a diagnosis of the main practices involving reuse and recycling of RCC’s by recycling cooperatives in the city of Belém do Pará. To this end, an RSL was performed that assisted in the development of tools for the application of this research, and also helped in the conduction of studies that deal with the theme. With RSL it was possible to conclude that no study unites RCC’s and recycling cooperatives as a way of mitigation. Along with the cooperatives a Survey was applied and then a Likert scale through which it was found that the 4 cooperatives are already handling RCC’s and that it is no longer intense due to the lack of communication channel between the RCC generators and the cooperatives. Therefore, it is concluded that cooperatives are important allies for better management and destination of RCC’s and it is interesting to explore their potential, increasingly mitigating environmental problems related to the lack of RCC management by the municipality in question and thus give a more appropriate destination with help and social contribution for the cooperatives and the population of the municipality in question
Acesso aberto (Open Access)
Dosagem experimental de concreto massa com adição de sílica ativa aplicado em barragem
(Universidade Federal do Pará, 2017-11-10) SOUZA, Grazielle Tigre de; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
The study of concrete dosage for large constructions, specifically of dams, has its own peculiarities due to the large volumes involved, intensifying the care with the supply and quality of materials used for these concretes, compositions with pozzolan additions are generally used in order to reduce the heat of hydration. In this sense, the main objective of this research is the elaboration of a mix design of concrete with the substitution of 8% of the cement per silica fume, the experimental study of the mix design was based on the Method of the Fineness Module of the Aggregates. To meet the proposal of this research, the methodology based primarily on the characterization of concrete constituent materials (fine and coarse aggregates, and silica fume), concrete mix design study by the Method of the Fineness Module (MFM) and subsequent analysis of the properties of the concrete mass obtained, making it possible to elaborate the concrete mix design, according to the requirements specified in the design of hydroelectric power plant structures. In this sense, with regard to the characterization of the aggregates, the results demonstrated the feasibility of the use of these in the production of concrete for dams. In relation to cement and silica fume the characteristics of these materials attend the normative requirements. The experimental dosage based on the MFM method, made it possible to compose the dosage graphs needed to define the mix design of concretes and consequently the verification of their applications in dams. It can be affirmed, thus, that the MMF approach developed in this research can be considered an important contribution, for the dissemination of the dosage methodology for concrete application in dams.
Acesso aberto (Open Access)
Emprego de Resíduo de Silício Metálico como Material Pozolânico na Produção de Cimento Portland Composto
(Universidade Federal do Pará, 2022-12-19) CUNHA, Rodrigo Rodrigues da; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
Civil construction, despite being an extremely important sector for the country's economic development, consumes a very significant amount of natural raw materials, in addition to being responsible for most of the consumption of cement produced in the world. The production of this material, in turn, causes many environmental impacts, resulting mainly from the sintering stage of clinker (main constituent of cement), which causes the emission of thousands of tons of CO2 into the atmosphere. In this sense, several studies have been carried out in order to point out an alternative material that can be used as a mineral addition to cement instead of clinker. Much of this research has sought to study the use of additions manufactured from the use of industrial waste. Given this context, the present work aims to analyze the behavior of a modified Portland cement of the CPIIZ-32 type, produced with partial replacement of clinker, by a residue from the pre-separator of the ferrosilicon - metallic silicon manufacturing process. - from an industry located in Breu Branco/PA. Therefore, at first, the physical and chemical characterization of the residue in natura and processed form was carried out, through the milling process, from the specific mass, FR-X, DR-X and activity index tests. pozzolanic with lime and cement. Then, 5 (five) blends of composite cement were formulated with different contents of ground silicon metal residue to analyze the mechanical behavior at 28 and 90 days of curing. Finally, a comparison was made of the physical-mechanical performance of the mortars produced with the use of modified cement and commercial cement of the CPIIZ-32 type. The results showed that the metallic silicon residue, after going through a pre-benefiting process (grinding for a period of 60 minutes) obtains properties consistent with the requirements stipulated by NBR 12653 (ABNT, 2014) to be considered as a pozzolanic addition. The use of this by-product for this purpose can generate enormous environmental benefits, reducing the impacts resulting from the clinker production stages, as well as being a viable alternative for the reverse logistics of this material, since the generating companies still do not have any form of reuse for this residue.
Acesso aberto (Open Access)
Estudo da colmatação em concretos permeáveis para tráfego leve e de pedestres
(Universidade Federal do Pará, 2020-05-28) TEIXEIRA, Mísley da Cruz; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Permeable concrete is a material mostly used as paving coating to reduce the effects of surface sealing. The material’s susceptibility to clogging is considered as a disadvantage, and it became an object of study in research about this material, as this one which evaluated the effect of clogging on permeable concretes used as pavement coating to light traffic. To this end, an experimental program was elaborated to characterize the material, designed with different percentages of fine aggregate, and to evaluate the evolution of clogging in permeable. The specimens were submitted to characterization and permeability tests after deposition cycles of different types of sediments (sand and clay) and cleaning by aspiration. The results of fresh material characterization corroborated the common assertion in the academic community that the insertion of fine aggregate in mix compositions increases the unit mass and the mechanical strengths and reduces the void percentage and the permeability of the concretes. The clogging tests proved that larger particle size sediments (sand) caused a loss of permeability due to sealing of the upper layer of the specimen, with loss ratios up to 21,13% at the end of the 20th sedimentation cycle, while the smaller particle size sediments (clay) induce to a deeper clogging, with a permeability reduction varying of 8,45% to 16,46%. The maintenance efficiency was proven by total recovery of clogging by sand, and a recovery percentage of 96,85% to clogging by clay. These results make it possible to declare that any particle size can clog the material, but also it is easy to recover its permeability by maintaining/cleaning of the pavement, which confirms that the pavement lifespan and raining capacity are directly associated to its periodic cleaning.