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Papers by normando barbosa

Zenodo (CERN European Organization for Nuclear Research), Jul 18, 2022

Construction is among the most energy-consuming human activities, and energy is a problem on a fi... more Construction is among the most energy-consuming human activities, and energy is a problem on a finite planet. There is a search for new technologies that bring improvements and solutions in the optimization of low energy incorporated materials and can minimize environmental impacts. Samples were made with water/gypsum ratio of 0.5 and 0.7, and citric acid contents of 0.0%, 0.010%, 0.020% and 0.030%. Therefore, it was possible to verify the influence of citric acid contents on gypsum paste and gypsum bamboo composites. The use of citric acid and triturated bamboo in gypsum matrix proved to be effective in this research.

Editora da Unicamp eBooks, 2020

Engenharia Agricola, Apr 1, 2021

The fabrication of traditional construction materials consumes a large amount of energy, emits po... more The fabrication of traditional construction materials consumes a large amount of energy, emits pollutants, and utilizes nonrenewable raw materials. Therefore, it is important to reduce the environmental impact of construction through the use of eco-friendly materials, such as bamboo. This work presents the characterization of Bambusa vulgaris, which is widely available in Brazil. The aim is to employ this raw material as a construction material. The geometric and physical properties were obtained. The results showed that, when bamboo is soaked in water, dimensional variations up to 7% were observed along the radial direction. The mechanical properties depend on the moisture content. The compressive strength can exceed 60 MPa with approximately 7% moisture content, while the tensile strength can exceed 100 MPa.

Cerâmica, Sep 1, 2019

The residue generated by industrial activities represents a cost, since the generators are respon... more The residue generated by industrial activities represents a cost, since the generators are responsible for its management, transportation, treatment and disposal. Rio Grande do Norte State in Brazil is the greatest producer of scheelite residue. The aim of this research was to characterize this mining residue, identify its similarity with natural sand and produce a coating mortar with it. In the composition of mortar, a Brazilian Portland cement type CPII-F32 and an industrialized calcium hydroxide as a binder were used. Laser granulometry, bulk and relative density, EDX, XRD and thermal analysis were done to obtain a physical and chemical characterization of the residue. Mechanical tests (tensile bond strength and compressive strength), SEM and water absorption test were done to analyze the behavior of mortar. All tests confirmed that mechanical properties were according to standards for tile mortar.

Zenodo (CERN European Organization for Nuclear Research), May 26, 2022

This paper reports a scientific initiation research on glue laminated bamboo panels, or engineere... more This paper reports a scientific initiation research on glue laminated bamboo panels, or engineered bamboo, using a polymeric biodegradable adhesive based on mamona oil, with a view to producing prototypes to get tectonic, eco-efficient and renewable architectural components. It was used the Dendrocalamus Asper bamboo culms from clumps existing in the Northeast Region of Brazil. Considering the importance of sealing systems for the delimitation of architectural spaces and the environmental impact caused by conventional masonry systems, floors and roofs, the investigation on glued laminated bamboo as a renewable and expressive material in these systems need to be deepened. KEYWORDS Glue laminated bamboo; biodegradable polymeric adhesives; eco-efficient sealing systems.

Concilium

Waste recycling is shown as an efficient alternative to minimize the impacts caused, such as the ... more Waste recycling is shown as an efficient alternative to minimize the impacts caused, such as the recovery of construction and demolition waste (CDW), but the properties should be studied and analyzed for their better use in concretes. In addition to environmental concern in the aggregate of concrete, another factor is the emission of CO2. Several studies are being done to replace part of the cement mass with other concrete components. Among these additions, it is possible to emphasize as the most used, in Brazil, the metakaolin. Studies show that concretes prepared with CDW generally tend to have a higher permeability, lower mechanical strength and difficulty in workability, and metakaolin as an additive that enhances the cementitious composite, compensating for the possible technical disadvantages of CDW as an aggregate. This work has as objective the macrostructural and microstructural analysis of concretes prepared with metakaolin and recycled aggregate CDW. A reference concrete,...

Cerâmica

Red ceramic waste (RCW) is one of the main by-products generated by the production of ceramic mat... more Red ceramic waste (RCW) is one of the main by-products generated by the production of ceramic materials. Its application in lightweight aggregates (LWAs) has not yet been tested. Thus, this review intends to evaluate the perspectives of using RCW in the manufacture of LWAs. The search was carried out in the ScienceDirect database. 47 articles were selected. A significant amount of data on the chemical, physical, mineralogical, and morphological properties of RCW are discussed. In most studies, the chemical constituents of RCW complied with the swelling parameters. The mineralogy of the residue usually has constituents capable of controlling the viscosity and aiding gas formation. The data of granulometry, microstructure, and loss of mass denote the need for special care with the methodology adopted for grinding and sintering of the residue. This review indicates that there is a high potential for the use of RCW in the manufacture of LWAs.

This work presents a model for non linear finite element analysis of reinforced concrete plane st... more This work presents a model for non linear finite element analysis of reinforced concrete plane structures. A four nodes concrete-steel composite, isoparametric, rectangular element is used. Before cracking, concrete is supposed to be into a plane stress state. The effects due to cracking and non linearity of the materials stress-strain relationships are taken into account by changing the elasticity matrix elements and by using a stress transfer process. A variable shear modulus is employed to take into account aggregate interlocking. Newton-Raphson's method of analysis is used. Stiffness matrices are modified at each iteration.

Journal of Building Engineering, 2021

The objective of the present investigation is to study the static and dynamic flexural behavior o... more The objective of the present investigation is to study the static and dynamic flexural behavior of bamboo as a functionally graded material to determine the Static Flexural Modulus (SFM) for untreated bamboo samples and to evaluate the effect of heat on the variation of the Dynamic Flexural Modulus (DFM). For the static flexural test, initially, the image processing has been carried out to establish the fiber distribution equation along the radial direction followed by the use to measure the tensile and compressive modulus of elasticity (MOE). The result of static flexural tests shows four different values of MOE at tensile and compressive state for inner and outer bamboo walls with low and high fiber density respectively. The average of the MOE at the tensile is circa 12% higher than in its compressive state. A non-destructive method, based on the impulse excitation technique is proposed for the heat-treated specimens to establish the DFM. The effects of different temperatures and time exposures as well as moisture content, on the DFM and weight of the specimens, have been considered in this study. Comparing the static and dynamic test results for untreated bamboo does not show a meaningful difference between SFM and DFM. The dynamic flexural test shows the effect of heat treatment on DFM to be less than 6% when heated for 3 h at 200 • C or when heated at 175 • C for 24 h.

Alvenarias de adobe estão certamente entre aquelas que menor impacto causam ao meio ambiente. No ... more Alvenarias de adobe estão certamente entre aquelas que menor impacto causam ao meio ambiente. No entanto, uma limitação dos adobes é sua vulnerabilidade à ação da água. Pode-se melhorar essa propriedade incorporando-se estabilizantes convencionais como cal e cimento, porém como nos adobes são usadas terras argilosas, a quantidade de estabilizante para ser efetiva, pode chegar a 8% ou mesmo 10% em massa. Neste trabalho propõe-se um novo método para estabilização da terra, através da ativação alcalina. Nesse processo, componentes mineralógicos do solo e de produtos a eles adicionados reagem internamente em um ambiente de pH elevado. A quantidade de ligante cai para 3% ou mesmo 2%. Em concretos, nos quais se requer altas resistências, utiliza-se silicato de sódio industrial, de preço elevado. No caso da estabilização da terra, utilizou-se uma mistura de sílica ativa com hidróxido de sódio para substituir o produto comercial. Para fornecer sílica e alumina amorfas, foram utilizados metaculim e/ou resíduos cerâmicos moídos. À mistura de hidróxido de cálcio, sílica ativa, metacaulim/resíduos cerâmicos, nas proporções adequadas chamou-se de ligante geopolimérico. Foram testados os teores de 0%, 1%, 2% e 3% desse ligante em relação à massa de terra. Percebeu-se que o ligante geopolimérico modifica as propriedades reológicas da mistura terraágua. Então, a quantidade de água para moldagem dos adobes foi aquela considerada adequada para tal, variando com a quantidade de ligante adicionado. Foi avaliado o efeito do ligante geopolimérico nas resistência à compressão, resistência à ação da água e variações dimensionais dos adobes. Os resultados mostram-se promissores, indicando um grande potencial para fabricação em larga escala de adobes com propriedades melhoradas.

Revista Principia, 2011

Esta pesquisa visa estudar a possibilidade de usar o solo de Juazeiro do Norte, localizado na Reg... more Esta pesquisa visa estudar a possibilidade de usar o solo de Juazeiro do Norte, localizado na Região do Cariri, no Estado do Ceará, para a fabricação de tijolos de terra crua. Este solo apresenta características peculiares em relação aos encontrados em todo o Brasil e seu uso como material de construção pode se constituir numa alternativa para minimizar os problemas habitacionais locais, além de não poluir o meio ambiente e ser acessível às populações carentes. Para conhecimento deste solo, realizou-se a sua caracterização. Posteriormente, determinaram-se as propriedades mecânicas dos blocos através dos ensaios de resistência à compressão simples e à tração indireta. O comportamento dos blocos frente à água foi investigado pelo ensaio de absorção. A durabilidade e a variação dimensional dos blocos também foram estudadas. Os resultados obtidos mostraram que o solo apresenta características granulométricas, resistência mecânica e durabilidades favoráveis à confecção de blocos prensados, sendo uma alternativa viável, sob os pontos de vista técnico, econômico e ecológico, levando à redução dos custos do produto final e o aproveitamento racional dos recursos naturais e humanos.

In this paper some results of research about lateritic stones as concrete aggregate are presented... more In this paper some results of research about lateritic stones as concrete aggregate are presented. Properties of lateritic stones are shown (mineral composition, abrasion and porosity). The mechanical characteristics of the lateritic concrete (L.C) are given. Experimental data obtained with beams made from reinforced lateritic concrete are presented and discussed. These are compared with data obtained using concrete made with granite aggregate (B.G). The results indicate that lateritic concrete has appreciably less resistance to compression (by 50-90%) than does concrete made with granite aggregate. The Modulus of Elasticity (Young's Modulus) of L.C. is also inferior to that of B.G. Lateritic concretes, however, are slightly less heavy. The change in compression resistance with either age or water/cement ratio is about the same for both types of concrete. As regards reinforced concrete beams, the behaviour under flexion of both L.C and B.G beams is similar; however the former is...

Conjecturas

O uso de coagulantes inorgânicos no tratamento de efluentes tem gerado discussões sobre os limite... more O uso de coagulantes inorgânicos no tratamento de efluentes tem gerado discussões sobre os limites de eficiência e os efeitos colaterais no corpo humano, buscando-se alternativas que desempenhem o tratamento com o impacto ambiental minimizado. O estudo objetiva avaliar a efetividade da palma orelha de elefante mexicana (Opuntia stricta haw) cultivada no estado da Paraíba no tratamento de águas e efluentes e seu potencial técnico como biocoagulante e biofloculante. Caracterizações de espectrofotometria no infravermelho – FTIR, análise termogravimétrica – TGA, difratometria de raios-x – DRX, teste de sólidos suspensos, níveis de turbidez e pH foram realizados. Os resultados obtidos indicaram que a espécie estudada reduziu a turbidez das amostras de efluentes em um percentual superior a 75% e a quantidade removida de sólidos suspensos é equivalente, além da detecção de componentes minerais nas amostras da palma estudada, que levanta a hipótese de atuar no equilíbrio dos níveis de pH, p...

International Journal of Design & Nature and Ecodynamics, 2014

Dragonfl ies are insects fi tted with two pairs of wings: a narrower pair located on the front si... more Dragonfl ies are insects fi tted with two pairs of wings: a narrower pair located on the front side and a wider pair located behind. The geometry of these wings has been studied by other authors, but differences between these are visible, showing structural differences designed by nature. The aim of this paper was to compare the structural behaviour (stress and strain) of both pairs of dragonfl y wings. The wings were simulated as grids supported in the animal body, according to natural geometry. The results show that the wings are composed of elements from 3 to 7 faces, and although similar to each other, there are some differences in structure and geometry between them: (i) the posterior wings support greater load because they have larger area (x2.4); (ii) the number of main structures connecting with the body in both is eight; (iii) the main connections in the anterior wings are closer, favouring the direction of fl ight; (iv) the posterior wings are set closer to the center of gravity of the insect, which causes the body weight to be supported by these wings, the anterior wings getting to the manoeuvres of fl ight; (v) analysis shows that the anterior wings support more concentrated efforts, while the posterior wings, due to their larger area, have reduced stress; (vi) the same is said of deformations, where the anterior wings deform more than the posterior wings (x2.4). Nature designed dragonfl y wings with different geometry and function, in which the anterior wings are responsible for handling the fl ight, and the posterior wings are responsible for sustaining the animal's body. The ratio between the number of frames and the number of joints is equal to the number of gold (1.618).