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Navegando por Assunto "Concrete"

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    Análise do comportamento mecânico de tubos de concreto com fibras de aço produzidos com materiais da região metropolitana de Belém do Pará
    (Universidade Federal do Pará, 2015-09-25) OLIVEIRA, Marco Antonio Barbosa de; POMPEU NETO, Bernardo Borges; http://lattes.cnpq.br/6564259204591721; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
    The steel fibers in the concrete pipes have provided better mechanical performance levels. In the northern region, uniquely in Belem, no studies on the technical feasibility of this technological resource, although there is considerable deficiency of urban infrastructure. Thus become relevant conduct studies on alternative technology. This study seeks to analyze the mechanical behavior of concrete pipes with steel fibers, aiming at the technical feasibility of replacing the concrete pipe with conventional armor. The research methodology we used steel fibers in loose state and glued comb DRAMIX® 3D type 65/35 and 80/60 DRAMIX® 3D type. For each fiber type were adopted contents of 20 kg / m³ (0.25%), 30 kg / m³ (0.38%) and 40 kg / m³ (0.50%) by weight and volume fraction, respectively. The size of all concrete pipes was 600 mm diameter, wall thickness of 60 mm and effective length 1000 mm, and the cylindrical bodies of the test piece of 100x200mm and prismatic of 150x150x500mm and 150x150x550mm, which were subjected to the tests for mechanical behavior evaluation and durability. In the production of concrete with the fibers was reviewed in the fresh state with frustoconical rebate between 0 and 10 mm. The dosage of concrete with fibers was routinely employed by the company for concrete without fibers, and the strength of the fibers takes place under the rule of the mixture. The results obtained that the concrete pipe with fiber type 80/60 loose at all levels and pasted comb the levels of 0.38% and 0.50%, reached the minimum breaking load and post-cracking set by the NBR 8900 (ABNT, 2007), thus would be technically feasible as the replacement of reinforced concrete pipes conventionally, under the conditions and specifications of this study.
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    Análise estrutural de concretos produzidos com resíduos de beneficiamento de placas de mármore e granito
    (Universidade Federal do Pará, 2019-05-06) BANDEIRA, Sandy Rebelo; MAGALHÃES, Edilson Marques; http://lattes.cnpq.br/1570353513360972
    The present work shows the feasibility of the use of cutting residues of marble and granite slabs in concrete production. The research was carried out in a series of stages, which comprised the collection of waste in the beneficiary companies, through the process of crushing, sieving of waste and production and breaking of specimens. The chemical analysis performed by x-ray fluorescence shows that the material meets the requirements of NBR 12653: 2015 for the concentration of aluminum, silicon and iron oxides, qualifying it as pozzolanic material. The results of axial compression showed that the mixtures produced with the substitution of aggregates meet the minimum requirements of NBR 6118: 2014 for application in structural elements subjected to moderate environmental aggression, class II. The traces were dosed following the instructions of the IPT / USP dosing method. 195 samples were produced, which were ruptured at 3, 7 and 28 days. Concrete was expected to reach at least 30 MPa at 28 days. The traces produced with the substitution of the aggregates presented smaller values than the reference trait. Regarding the absorption, it was observed that the traces with substitution of aggregates presented a slight increase in water consumption, which may explain the reduction in the indices of compressive strength.
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    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.
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    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.
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    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.
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    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.
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    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.
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    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.
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    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
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    Estudo da potencialidade da cinza da casca do murumuru, um resíduo agro industrial amazônico como filler ao concreto estrutural
    (Universidade Federal do Pará, 2022-11-17) SOUZA, Milleno Ramos de; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042; TEIXEIRA, Marcelo Rassy; http://lattes.cnpq.br/8912916360456192
    The use of agro-industrial waste in the partial replacement of cement in concrete has been the subject of research that analyzes the possible improvements in mechanical and physical properties and durability of the concrete, in addition to providing the use of mineral additions of natural origin or partial replacement in relation to the constituent materials of the composite, waste that would have inappropriate disposal, such as open-air landfills and burning. With this scenario, the study aims to research the use of murumuru husk ash (MHA), an agro-industrial waste generated specifically in the Amazon region as partial replacement of cement in structural concrete and evaluate the physical, chemical and mineralogical characteristics of the ash to act as filler in concrete, and its properties in the fresh and hardened state in concrete. With this purpose, the MHA underwent the physical-mechanical characterization tests such as specific mass, pozzolanic activity with Portland cement, pozzolanic activity with lime and BET test, also performing the mineralogical and chemical analysis of the ash. For concreting, a mix 1:1.6:2.4 (by mass) with water/cement ratio of 0.43 was considered, with replacement levels of 0%, 6%, 9% and 13% of the cement mass by MHA. After the dosage, the tests were performed on the concrete in its fresh and hardened state: slump test, specific mass, compressive strength (28 days), tensile strength in diametrical compression, water absorption by capillarities, specific mass in the hardened state, modulus of elasticity and morphological evaluation, through the Scanning Electron Microscope (SEM). Checking first the properties of concrete in the fresh state, it is evaluated that the insertion of the waste decreased the consistency and decreases the specific mass, except the concrete for the content of 6% that there was a 10% increase in the specific mass in relation to the concrete reference. Regarding the properties in the hardened state, the replacement by CCM showed an increase specifically in compressive and tensile strength in the 6% content at 28 days around 1% and 9% respectively, occurring a decrease in the contents of 9% and 13%. The results showed that there is a technical feasibility with partial replacement of 6% of MHA in cement, using plasticizer additive to improve workability
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    Estudo e avaliação do uso de resíduos do processo Bayer como matéria-prima na produção de agregados sintéticos para a construção civil
    (Universidade Federal do Pará, 2010-03) SOUZA, José Antônio da Silva; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785
    The large amount of solid waste coming from mines and metallurgical industries became a serious social-environmental problem. The physical and chemical features of this material can raise a great interest in other industries. The ceramic industry might be a great costumer for most of this material, since it can supply the current lack of raw material. The red mud, main industrial residue of the alumina manufacturing, has been a very interesting input for several kinds of aggregates manufacturing used for the concrete production in civil engineering. In this context, this paper deals with studies concerning the red mud recycling to be applied as raw material for the synthetic light aggregate production to be used as an alternative material in the civil construction industry. This is because of its physical-chemical features and the large amount annually produced (around 10 million tons within two factories in the North of Brazil). The studies completed in this work show the feasibility of aggregates manufacturing, with different properties and possibilities. These properties depend on the parameters control such as content of free silica and clay, and the sintering temperature. Such variables allow to perfectly controlling the glassy phase formation which is responsible for the aggregate properties such as: porosity, mechanical resistance and density. This material can be used for conventional or special concretes to supply the civil engineering needs.
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    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.
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    Influência do resíduo do caulim tratado termicamente da região Amazônica e o seu potencial uso como material suplementar ao cimento Portland.
    (Universidade Federal do Pará, 2022-11-23) SOUZA, Márcio Rodrigo Nunes de; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
    Mineral industries produce waste in large quantities and in different types and levels of danger, such as the kaolin processing industry, which produces waste based on silica, mica and kaolinite. The disposal of this material in an inappropriate place causes a strong environmental impact, which could be minimized with the use of this waste as raw material for use in civil construction. This work aims to study the incorporation of calcined kaolin residues as a supplementary material to cement and concrete for use in civil construction. In this research, kaolin residues from the Felipe mine located in the south of Amapá were used, being carried out physical, chemical and mineralogical characterization tests, the pozzolanic activity index of the calcined residues at temperatures 500ºC, 700ºC and 900ºC, as well as the analysis heat, according to ABNT standards. For the mechanical technological tests (Simple compressive strength tests, modulus of deformation and tensile strength by diametral compression) and durability (Water absorption tests by immersion and water absorption test by capillarity), were incorporated with 0%, 10%, 15% and 20% of calcined kaolin waste, replacing part of the Portland cement. The results obtained showed that the calcined residues presented high pozzolanic activity at a temperature of 700ºC, the use of calcined kaolin residue presented mechanical behavior and durability as a supplementary material to cement and concrete within the ABNT norms, and finally we concluded that there is viability technique of using waste for use in civil construction as a supplementary material to cement, as well as use for high-strength concrete.
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    Influência no comportamento mecânico do concreto com a utilização de microfibras de polipropileno para redução do efeito de retração: um estudo realizado em Belém do Pará
    (Universidade Federal do Pará, 2022-10-27) CUNHA, Wictor Alencar; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
    Seeking to mitigate the effect of concrete shrinkage, the influence on the mechanical behavior of concrete reinforced with polypropylene microfibers was studied in this study. In the experimental program, 15 (fifteen) study series were produced: one reference without the addition of polypropylene microfiber for each w/c ratio studied, totaling 3 series; and another 12 (twelve) series with the following characteristics: addition of 0.6% and 1.0% of microfiber content varying the length in 12 mm and 25 mm, the w/c ratios being studied with values of 0.45 ; 0.55 and 0.65. Tests were carried out in the fresh state of the concrete to evaluate consistency and workability; and in the hardened state to evaluate compressive strength, flexural traction and modulus of elasticity with age of the specimens at 7 and 28 days; and dimensional variation with age of 48h, 7 and 28 days. The results obtained were studied through analysis of variance (ANOVA) and the Tukey test to determine the statistical significance of the responses found. It was concluded that the optimum content of addition of polypropylene microfiber to concrete was 1.0% with fibers of 12 mm length and w/c ratio=0.55.
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    Rejeito de manganês, proveniente da Amazônia Oriental, em substituição parcial do agregado miúdo natural em concreto
    (Universidade Federal do Pará, 2019-03-21) SILVA JÚNIOR, Paulo Rogério; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
    Research on partial or total substitution of the natural fine aggregate for ore tailings has gained strength in recent years. Most part of these tailings are destined to dams, which are subject of ruptures resulting in social, economic and environmental loses. The most recent example is the rupture of Brumadinho-MG dam in january, 2019. Despite of all the risks associated to the mining activity, the extraction of ore tends to increase due to the final products generated by this activity such as steel, batteries and electronics. Natural sand is mostly obtained by dredging activity, which involves the deforestation of certain areas and the possible contamination of the water with diesel oil from dredgers. This research aims to study the partial replacement of natural sand by manganese tailing (in 15%, 20%, 25% and 30% proportions) from the eastern Amazonia, Marabá-PA municipality, for the construction of structural concrete without the use of superplasticizer. Analyzed the results for the test of workability, mechanical strength, water absorption and microstructure for the samples of concrete with and without tailings. It has been found that manganese tailing is a thin material that has a high specific surface, which demands high demand for water when compared to the reference concrete. It was verified that there was a decrease in the mechanical properties of the refuse concrete due to the added water, however, the water absorption was equal to the reference one.
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    Rejeito do minério de manganês como material de construção civil
    (Universidade Federal do Pará, 2017-06-02) VIVEIROS, Danielle de Cássia Santos de; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
    The increasing global demand for manganese ore and environmental impacts associated with the disposal of ore waste have motivated studies about the reuse of materials from tailings dams. In this context, the main objective of this work was to study the reuse of manganese waste as materials for civil construction. For this purpose a characterization of the Mn tailings was made from a physical, chemical, mineralogical, environmental and reactivity point of view. From these analyzes, feasible applications for the tailings were investigated. The first one was to study its reutilization as a filler in Portland cement. For this, reference mortars and mortars with 6, 8 and 10% substitutions were made to the cement. The mortars were tested for compressive strength and total water absorption and voids index at 28 days. The tests showed that the mortars with substitution contents obtained positive results when compared to the reference mortars. Inducing the resistance gain mainly for the percentages of 6 and 8%, as well as for the results of total absorption and voids index. A second investigation was carried out to study the reuse of Mn tailings as a fine aggregate in the manufacture of concrete. For this purpose, reference concrete and concretes were made with 15, 20, 25 and 30% substitutions to the natural fine aggregate. Through the analysis of resistance to axial compression a positive result was observed for both samples, especially for concretes with 15 and 20% substitution. The tests of tensile strength and modulus of elasticity achieved satisfactory results for both samples, especially for concretes with 20, 25 and 30% of substitution. In the capillary absorption analysis, the concretes with substitutions presented significant variations when compared to the reference concretes. The samples of 15% and 30% were the ones that less absorbed water, and the results of the 20 and 25% samples were still below the absorption values of the reference concrete. In this way, the reuse of this waste as materials for civil construction becomes feasible from a technical and environmental point of view.
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