Programa de Pós-Graduação em Engenharia de Infraestrutura e Desenvolvimento Energético - PPGINDE/NDAE/Tucuruí

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/9400

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Agora exibindo 1 - 6 de 6

Acesso aberto (Open Access)
Análise da viabilidade técnico-econômica de implantação de reciclagem de pneus para produção de CBUQ em Tucuruí
(Universidade Federal do Pará, 2019-02-21) MOUSINHO, Mateus Mamede; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Population growth and rapid technological development have contributed to increased solid waste generation by improperly disposing of post-consumer tires, which are not biodegradable and their decomposition time is not yet precisely determined. To be defended that the recycling culture does not only show aspects of environmental and educational preservation, it is also necessary to justify recycling as an economic activity that generates employment and income to the city, contributing to the well-being and quality of life. Therefore, the main objective of this research was to quantify the discard of waste tires and to analyze the technical-economical feasibility for the implementation of the recycling process of waste tires in the production of rubber aggregate in the asphalt mixture at the city's asphalt plant. To do so, it was measured the disposal of waste tires in a given period in Tucuruí and estimated the disposal volume of the adjacent cities, in addition, it was analyzed the operational activities and production costs of the waste as a rubber aggregate. In the field survey, 98 questionnaires were applied in 30 neighborhoods where the establishments were in January 2018. Thus, there was a monthly amount of 1,664 tires in the rubber workshops, 2,347 tires in the mechanical stores, totaling 4,011 tires in the municipality, which allows to conclude that the city presents a large volume of this solid residue. Adjacent cities presented in their estimate a total of 8,031 tires unserviceable per month. For the production of the rubber aggregate asphalt mixture, the conventional CBUQ trait was used in relation to the modified CBUQ developed by Coelho (2018), in which it was estimated that one kilometer of asphalt mixture of thickness of 3,5 centimeters can be used approximately 11.72 tonnes of recycled aggregate (8.79 tonnes of rubber and 2.93 tonnes of wood sawdust), this is equivalent to 1,465 car tires or 5,170 motorcycle tires, leading to an economy in the purchase of raw material from R$ 56,075.41 per kilometer. It is concluded that the results of the three scenarios are satisfactory, the simulations of the study were only the resources available to produce the rubber aggregate generated by the municipality as a pioneer project, with the intention that other municipalities are part of this visual identity of sustainable city.
Acesso aberto (Open Access)
Análise experimental da resistência à punção em lajes lisas com substituição de agregados graúdos naturais por reciclados de concreto
(Universidade Federal do Pará, 2022-05-12) RIBEIRO JUNIOR, Jayron Alves; FERREIRA, Maurício de Pina; http://lattes.cnpq.br/4242041552985485; https://orcid.org/0000-0001-8905-9479
The popularization of the use of recycled concrete aggregates has increased due to socioeconomic aspects, but above all, as sustainability is being pursued and, in this context, some international standards have been published to facilitate and standardize the use of this material. Despite the constant evolution of studies on punching shear, there is a need for national and international regulatory adjustments in relation to the use of recycled concrete aggregates in flat reinforced concrete slabs. Two reasons explain the slight influence of the incorporation of recycled aggregates on the punching shear resistance of concrete slabs: lower mechanical strength and better bond between the cement paste and the recycled concrete aggregate due to the higher cement content, porosity, and roughness, when compared with natural aggregate. Thus, the punching shear strength is influenced by these properties of the aggregates along the shear plane of the cracks, the two effects offset each other, leading to a similar punching shear strength. This research carried out the experimental test of 6 flat slabs of reinforced concrete without shear reinforcement subjected to symmetrical loading, containing variations in the rate of flexural combat reinforcement (0.7% and 1.4%) and replacement rate of natural aggregate by recycled concrete aggregate (0%, 30% and 100%). The study evaluated the influence of these variables on the punching shear resistant capacity and analyzed the upper limits of resistance. The slabs were octagonal with 2500 mm of distance between parallel faces, sides of 1030 mm and thickness of 210 mm, molded with concrete with fck of 25 MPa and supported on columns of 300 mm of side. The standards used as a parameter for estimating resistant capacity were NBR 6118:2014, ACI 318:2019 and Eurocode 2:2004. The experimental results showed that the slabs with ARCO showed a maximum reduction of 6 % in the punching shear resistance when compared to the slabs with conventional coarse aggregates. The reinforcement rate was able to increase the cracking load at the service limit state (ELS) and the recycled concrete aggregate had little influence on the opening of cracks in the slabs with the highest rate of flexural reinforcement.
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)
Concreto auto adensável com agregado miúdo reciclado de concreto
(Universidade Federal do Pará, 2019-03-29) BERNARDO, Karen Suely Martins; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
A more sustainable approach in the production of self-compacting concrete (SCC) aims to replace the natural aggregates by recycled concrete aggregates, however this substitution affects the properties of the concrete produced. This research propose evaluate the effect of the fine recycled aggregate on the properties in the fresh and hardened state of self-compacting concrete using a methodology of dosage focused on the rheology of materials. The dosage study was performed through an adaptation of the Gomes method, and four levels of FNA substitution by FRCA were determined (10%, 20% and 30%). Were analyzed the fresh state properties according to the parameters established according to the specifications on the subject and by the normative prescription of reference, and the properties in the hardened state. In this study, was observed a decrease in apparent viscosity, passing ability and segregation resistance, proportional to the increase in FNA substitution. However, all mix designs have attend the required of self-compacting, with minimum adjustments. All concretes obtained axial compressive strength at which fit in the structural concrete class. Therefore, through the responses founded during the dosing study, it was possible to produce self-compacting concretes with 30% of FRCA that met the requirements established.
Acesso aberto (Open Access)
Formulações de argamassas autonivelantes para contrapiso com incorporação parcial de agregado reciclado de concreto
(Universidade Federal do Pará, 2019-01-21) OLIVEIRA, Thais Valadares; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Self-leveling mortar is a material with advantageous characteristics for the industry of civil construction, among them: high flatness, low thickness of the elements that use it, rapid application and short demand of labor for its execution. In order to add knowledge about this material, as well as to make it more sustainable, by incorporating recycled concrete aggregates in its mixture, the present work was proposed. The main objective was to build self-leveling mortars with incorporation of these residues and to characterize them in the fresh state, verifying the technical feasibility of their use. Furthermore, in a complementary manner, it was observed how different combinations of additives may influence the properties of these mortars. Based on the use of a base formulation, available in the literature, eight traces were produced, including four variations of replacement of common sand by recycled aggregate (0%, 25%, 50% and 75%) and two possible combinations of additives, one employing in parallel a superplasticizer additive and a viscosity modifying additive and another in which only one polyfunctional plasticizer additive was applied. Initially, each mixture passed through individual adjustments so as to have adequate consistency, flow time and visual configuration, without demonstrating the occurrence of exudation or segregation. Thereafter, fresh tests were carried out to verify exudation, mass density, incorporated air content and curing time of the mortars. At the end of the research, it was noticed that the incorporation of recycled aggregate in self-leveling mortars could be a technically feasible option, and even advantageous for the mortars formulated with it, considering the evaluated properties, by reducing, among the mixtures with the residue and those ones of reference, the amount of additive employed (up to 0.2%), the exudation (the quantity of water exuded reached 2.04% in a mixture with recycled aggregate and 2.61% in a mixture of reference), the incorporated air content (ranging from 0.17% to 1.34% between traces with and without recycled aggregate) and the mass density (reduced up to 5.5%). Among the combinations of additives, in turn, it was observed that the most satisfactory was the one that employed polyfunctional additive.
Acesso aberto (Open Access)
A influência dos agregados reciclados de resíduos da construção civil nas propriedades do concreto permeável: uma revisão sistemática
(Universidade Federal do Pará, 2023-01-27) OLIVEIRA, Thainá Maria da Costa; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
Sustainable development in the civil construction sector has been increasingly promoting the advancement of research on sustainable technologies in order to mitigate the problems caused by this sector. In view of the above, a sustainable measure that aims to reduce the consumption of natural resources and the irregular disposal of waste is the practice of reuse and/or recycling of RCC, and as a solution to flood control, the use of permeable concrete (CPER) is proposed. Due to the lack of standardization and divergence of the procedures determined for the characterization of the CPER with recycled aggregate, it became necessary to analyze the scientific knowledge of this material and demonstrate the feasibility of using RCC in the production of the CPER. In view of the above, this research aims to contribute to the knowledge about the use of recycled aggregates in the production of pervious concrete, through the selection of articles in databases from the last 15 years, in order to evaluate the properties acquired by materials with different types, sizes and contents of recycled aggregates. The present research used the Systematic Literature Review (RSL) as methodology for conducting the study. The articles were collected from the four most prestigious scientific bases for publications on themes related to civil construction. To screen the articles and prepare the RSL, the StArt tool was used, and data extraction from the studies was defined in the research protocol prepared. The results showed that the subject gained more relevance in the year 2016, the Science Direct database presented the highest number of articles, 80% of the works used coarse aggregates in the production of CPER, the percentages of substitution most used among the researches were 100% and 50%. Structural and mixed concrete waste were the most used as recycled aggregates in the production of CPER. It was possible to note great dispersion between the data collected in the surveys and the component materials of the CPER. Moreover, it was found that all types of aggregates met the strength and porosity values determined by the ACI and the permeability met both standards, except for the glass waste. Thus, the application of recycled aggregate in the production of CPER was evaluated as an adequate solution to the problems of irregular waste disposal and shortage of natural aggregates.

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