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Search Results: 1 - 10 of 32419 matches for " Antonio Ludovico Beraldo "
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Portland Cement Mortar Composite with Partial Sand Replacement by Eggshell Particles  [PDF]
Antonio Ludovico Beraldo
Open Journal of Inorganic Non-metallic Materials (OJINM) , 2014, DOI: 10.4236/ojinm.2014.44007
Abstract: Agro-industrial activities generate a large amount of wastes. According to their specific properties, most of them can partially replace mineral aggregates, aiming to produce non-structural cement composites. In this research work, the behavior of a Portland cement mortar with partial replacement of sand by treated eggshell particles (0% to 66%) has been evaluated. Firstly, chemical compatibility between eggshell particles and Portland cement was carried by hydration curves. In a second step, a mixture of cement mortar based on treated eggshell (cold water, warm water and oven-dry) was prepared. Composite hardening was monitored by an ultrasound technique. At initial ages, ultrasonic pulse velocity (UPV) along the time was sensitivity enough to detect the sand-to-eggshell ratio effect. Compressive strength at 28 days ranged from 23 to 9 MPa depending on sand to eggshell particles ratio, which indicated that the composite was suitable for non-bearing structures, mainly at rural areas.
Portland Cement-Residues-Polymers Composites and Its Application to the Hollow Blocks Manufacturing  [PDF]
Augusto Cesare Stancato, Antonio Ludovico Beraldo
Open Journal of Composite Materials (OJCM) , 2013, DOI: 10.4236/ojcm.2013.31001
Abstract: Agricultural wastes and sawdust combined with cement matrix in the manufacture of building elements has been practiced with success in developed countries. In this study, sawdust from wood species (Pinus caribaea and Eucalyptus grandis) and an agricultural waste—rice husk (Oriza sativa) were combined with Portland cement type V (high initial strength), modified by polymer styrene-butadiene (SBR) addition. Hollow blocks produced with Eucalyptus grandis and rice husk residues showed better compressive strength; however, those produced with residues derived from Pinus caribaea presented non-satisfactory results, due to the particle size that was used.
Effects of thermal treatment on the physicochemical characteristics of giant bamboo
Wandivaldi Antonio Colla,Antonio Ludovico Beraldo,José Otávio Brito
CERNE , 2011,
Abstract: Despite countless use possibilities for bamboo, this material has two major disadvantages. One drawback is the low natural durability of most bamboo species due to presence of starch in their parenchyma cells. The other equally important drawback is the tendency bamboo has to present dimensional variations if subjected to environmental change conditions. In an attempt to minimize these inconveniences, strips (laths) of Dendrocalamus giganteus Munro were taken from different portions of the culm and subjected to several temperatures, namely 140 °C, 180 °C, 220 °C, 260 °C and 300 °C under laboratory conditions, at the ESALQ-USP college of agriculture. The thermal treatment process was conducted in noninert and inert atmospheres (with nitrogen), depending on temperature Specimens were then subjected to physicomechanical characterization tests in order to determine optimum thermal treatment conditions in which to preserve to the extent possible the original bamboo properties. Results revealed that there is an optimum temperature range, between 140 ° and 220 °C, whereby thermally treated bamboo does not significantly lose its mechanical properties while at the same time showing greater dimensional stability in the presence of moisture.
Tableros de partículas de bambú (Bambusa vulgaris Schrad) y resina poliuretana a base de aceite de rícino (Ricinus communis L.)
José, Flávio Januário;Beraldo, Antonio Ludovico;
Ambiente Construído , 2010, DOI: 10.1590/S1678-86212010000400018
Abstract: the aim of this study was to manufacture and evaluate particleboards made with two alternative materials, seeking to develop a sustainable production process. particles from bambusa vulgaris schrad were used because of the fast production cycle of this species. the binder used was castor oil (ricinus communis l.) based polyurethane resin, since it is partially produced by a renewable source and it is considered to be non-toxic. for the characterization of the material, boards made of bamboo particles smaller than 2.4 mm, combined with 5%, 10% and 15% resin content in relation to the bamboo-particle mass, were manufactured at laboratory scale. specimens were evaluated according to the brazilian standard nbr 14810 - agglomerate wood boards. before the longitudinal compression tests, the specimens were tested by means of a non-destructive ultrasound evaluation. the results showed that the boards with 10% resin content were not statistically different from those with 15% resin content, and both were superior to boards with 5% resin content. most of the board properties were inferior to those of commercial boards. it was not possible to correlate ultrasonic pulse velocity across the specimens with longitudinal compression strength.
TéCNICA DE MOIRé APLICADA AL ANáLISIS DE ESFUERZOS DE COMPRESIóN EN EL BAMBú GUADUA MOIRé TECHNIQUE APPLIED IN COMPRESSION STRESS OF BAMBOO GUADUA
Ant?nio Ludovico Beraldo,Daniel Albiero,Antonio José da Silva Maciel,Inácio Maria Dal Fabbro
MADERAS : Ciencia y Tecnología , 2007,
Abstract: El bambú es considerado como una materia prima muy importante para los paises en vias de desarrollo, pues combina levedad con una elevada resistencia mecánica. Hasta ahora no se conoce adecuadamente el comportamiento del material cuando es sometido a los ensayos de caracterización mecánica. En este trabajo se buscó evaluar probetas de bambú (Guadua angustifolia) sometidas al ensayo de compresión simple. Se utilizó la técnica de moiré de sombra para mapear las deformaciones de las probetas en función de la cantidad de nudos presentes en ella (0, 1 ó 2). Los resultados obtenidos evidenciaron la adecuación de la técnica utilizada, permitiendo observar la distribución de las lineas de iso-deformación en el bambú Bamboo is considered an important raw material in developing countries because its physical characteristics associate lightness with high mechanical resistance. However its behavior obtained from mechanical tests is not yet well defined. This research work had the objective of evaluating bamboo (Guadua angustifolia) testing specimens under simple uniaxial compression loading. Shadow moiré optical methods had been employed to generate deformation mapping as function of knots (0, 1 or 2). Obtained results indicate that the technique is well adequate in generating iso-deformation contour lines in bamboo specimens
TéCNICA DE MOIRé APLICADA AL ANáLISIS DE ESFUERZOS DE COMPRESIóN EN EL BAMBú GUADUA
Beraldo,Ant?nio Ludovico; Albiero,Daniel; da Silva Maciel,Antonio José; Dal Fabbro,Inácio Maria; Rodrigues,Silvestre;
Maderas. Ciencia y tecnología , 2007, DOI: 10.4067/S0718-221X2007000300010
Abstract: bamboo is considered an important raw material in developing countries because its physical characteristics associate lightness with high mechanical resistance. however its behavior obtained from mechanical tests is not yet well defined. this research work had the objective of evaluating bamboo (guadua angustifolia) testing specimens under simple uniaxial compression loading. shadow moiré optical methods had been employed to generate deformation mapping as function of knots (0, 1 or 2). obtained results indicate that the technique is well adequate in generating iso-deformation contour lines in bamboo specimens
Compuestos no- estructurales de cementos comerciales y aserrín de maderas Argentinas
Beraldo,Antonio L; Balzam,Humberto;
Maderas. Ciencia y tecnología , 2009, DOI: 10.4067/S0718-221X2009000300006
Abstract: the most part of residues generated during wood mechanic processing remains unexplored for construction material non-structural compounds production. eucalyptus grandis and cottonwood (poplar sp) particles were submitted to several treatments, combining three cements (blast furnace slag, high initial strength and puzolanic). firstly, binder reaction efficacy was investigated by means a calorimetric test (mixture hydration curves). after, cylindrical specimens were submitted to a compression test at 14 days old. also, ultrasonic pulse velocity (upv) was obtained during composite hardening process. results obtained were very coherent detecting the effect of the biomass and cement types, the effect of the treatment applied to the wood particles and the interaction between these parameters. the most effective combination was obtained when a combination of e. grandis particles with blast furnace slag or high initial strength cements, both with 3% calcium chloride addition was used.
Compuestos no- estructurales de cementos comerciales y aserrín de maderas Argentinas Non-structural composites of sawdust from Argentina wood species and comercial cements
Antonio L Beraldo,Humberto Balzam
MADERAS : Ciencia y Tecnología , 2009,
Abstract: En el procesamiento mecánico de la madera se generan importantes volúmenes de residuos los cuales en su mayor parte aún no se emplean en la fabricación de componentes para la construcción. En este trabajo investigativo, se evaluó el comportamiento de un compuesto no-estructural de aserrín de dos especies de maderas argentinas combinadas con tres tipos de cementos comerciales. Partículas de maderas (Eucalyptus grandis y Poplar sp) fueron sometidas a diversos tratamientos y combinadas con tres tipos de cementos comerciales (CPC40, ARI50 y CPP40). Inicialmente, la eficiencia de la reacción fue investigada por medio del ensayo calorimétrico (curva de hidratación). A seguir, probetas cilíndricas fueron sometidas al ensayo de compresión simple, después de 14 días de fabricación. Al mismo tiempo, la velocidad del pulso ultrasónico (VPU) fue evaluada durante la etapa de endurecimiento de las mezclas. Los resultados obtenidos se mostraron muy coherentes entre sí, permitiendo destacar los efectos de los factores naturaleza de la madera, tipo de cemento y tipo de tratamiento, además de las interacciones entre estos factores. La combinación más efectiva fue el empleo de partículas de E. grandis, combinadas indistintamente con los cementos CPC40 o ARI50, adicionados con 3% de cloruro de calcio. The most part of residues generated during wood mechanic processing remains unexplored for construction material non-structural compounds production. Eucalyptus grandis and Cottonwood (Poplar sp) particles were submitted to several treatments, combining three cements (blast furnace slag, high initial strength and puzolanic). Firstly, binder reaction efficacy was investigated by means a calorimetric test (mixture hydration curves). After, cylindrical specimens were submitted to a compression test at 14 days old. Also, ultrasonic pulse velocity (UPV) was obtained during composite hardening process. Results obtained were very coherent detecting the effect of the biomass and cement types, the effect of the treatment applied to the wood particles and the interaction between these parameters. The most effective combination was obtained when a combination of E. grandis particles with blast furnace slag or high initial strength cements, both with 3% calcium chloride addition was used.
Caracteriza??o física e mecanica de argamassas à base de cimento Portland e cinza de casca de arroz residual
Rodrigues, Michelle S;Beraldo, Antonio L;
Engenharia Agrícola , 2010, DOI: 10.1590/S0100-69162010000200001
Abstract: rice husk, employed as an energy source at milling industries in brazil generates, after burning, a dark ash. this residue is not yet conveniently disposed, being currently dumped on large areas, causing environmental problems. this research intended to evaluate the applications of residual rice husk ashes (rha) as a partial replacement of cement for mortar production. rice husk ash was chemically characterized through x-ray fluorescence, determination of carbon content, x-ray diffraction, and laser granulometric analysis. mortar specimens were submitted to two different exposure conditions: internal and external environments at a maximum period of five months. physical-mechanical testing were compressive strength and ultrasonic pulse velocity (upv). although presenting good mechanical performance, the mortar based on ash (rha) did not present pozolanicity but it can be employed in cement matrices as inert material (filler).
Efeito da adi??o de cinza da casca de arroz em misturas cimento-casca de arroz
Zucco, Loris L.;Beraldo, Antonio L.;
Engenharia Agrícola , 2008, DOI: 10.1590/S0100-69162008000200002
Abstract: the rice husk and its ash are abundant and renewable and can be used to obtain alternative building materials. an increase in the consumption of such waste could help minimize the environmental problems from their improper disposal. this study aimed to evaluate the use of ashes as a cargo mineral (filler). however, the rice husk chemically interferes in the conduct of the based cement mixtures. thus, different mixes cement-rice husk with and without the addition of ash were evaluated in order to highlight the influence of its components (husk; ash), which could otherwise be excluded or be underestimated. cylindrical samples (test of simple compression and traction by diametrical compression) and samples extracted from manufactured pressed board (test of bending and parallel compression to the surface), were used to evaluate the behavior of different mixtures of components (rice hush; rha - rice husk ahs). the results of the mechanical tests showed, in general, there is not a statistical difference between the mixtures, which are associated with the chemical suppressive effect of the rice husk ash. the mixture of rice husk of 10 mm, with an addition of 35% of the rice husk ash, is notable for allowing the highest consumption of rice husk and rice husk ash, to reduce 25% the consumption of cement and to allow the storage (without emissions to the atmosphere), around 1.9 ton of co2 per ton of cement consumed, thus contributing to the reduction of co2 emissions, which can stimulate rural constructions under an ecological point of view.
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