Navegando por Assunto "Reaproveitamento (Sobras, refugos, etc.)"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Análise das propriedades tecnológicas da cinza do caroço de açaí na cerâmica vermelha
(Universidade Federal do Pará, 2019-09-16) FERREIRA, Taiana da Silva; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783; ISHIHARA, Júnior Hiroyuki; http://lattes.cnpq.br/3498874642887006; https://orcid.org/0000-0002-0081-7913
The raw materials from the exploration of deposits used for the manufacture of products used in construction and the environmental impacts caused by the red ceramic sector evolved as cities developed. The need for the use of alternative materials, such as waste biomass, has become increasingly necessary studies aimed at the reuse of waste in the process of production and manufacture of ceramic materials. Thus, this work has the objective of evaluating the incorporation of ash from the acai kernel residue (RCA) in the clay mass and to evaluate the technological properties of red ceramic. The materials were chemically and physically characterized, and then extruded specimens were molded using 0%, 10%, 15% and 20% RCA ash mixed in two types of clay, called red clay and dark clay. After firing at 950 ºC, the pieces were subjected to water absorption, apparent porosity, specific gravity, linear shrinkage and flexural strength stress tests. The results showed that the use of RCA ash contributed to the workability of the mixtures, reducing the need for additional water for molding. It was also verified that the 10% ash content as a partial substitute of red clay, and the mass containing 50% of red clay and 50% of dark clay, had a positive influence on the evaluated technological properties. However, for the 20% ash incorporation of RCA, the values were median and for the unsatisfactory porosity assay. Thus, it was possible to verify the technical feasibility of using açaí stone ash in partial substitutions, contributing to the reduction of raw material exploration, reduction of solid waste disposal and the reuse of the residual biomass of açaí stone in the production of ceramic materials.
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)
Desenvolvimento de um aplicativo móvel para promover o reaproveitamento de resíduos na dosagem de concreto
(Universidade Federal do Pará, 2019-09-04) MESQUITA, Felipe José Marques; FÜLBER, Heleno; http://lattes.cnpq.br/5018616409948511; ISHIHARA, Júnior Hiroyuki; http://lattes.cnpq.br/3498874642887006; https://orcid.org/0000-0002-0081-7913
Concrete is the most widely used building material in the world, resulting in high consumption of natural materials, thus, the reuse of waste in substitution of cement and aggregates in the production of concrete enables reduction of greenhouse gas emissions, reduction in extraction of natural raw materials, in addition to the reduction on the disposal of these wastes in nature. Given the need to develop solutions that contribute to the efficient reuse of waste, this paper aimed to analyze the state of the art of national production of concrete with waste reuse, to develop a mobile application to promote the reuse of waste in concrete production. Through bibliometric analysis of Brazilian publications on concrete with reuse of waste, we analyzed works published over a period of 20 years in the Web of Science database, revealing growing interest on the subject, especially the construction and demolition waste, being this the most published and protagonist residue of the most influential article on the subject. The analysis of the publications allowed the creation of a knowledge base on the use of waste in concrete production. These data were used in the development of an application for Android mobile devices, which allows the user to have easy access to concrete dosages with reuse of residues, obtain information on potential waste suppliers and calculate the production costs of this concrete. The system has 41 different mix proportioning, including 7 concrete types and 10 waste options, allowing the user to achieve environmental gains by replacing up to 100% of natural concrete aggregates with waste and saving up to 11.82% over cost. of concrete produced without waste. Keyword: concrete, waste, database, application, bibliometrics.