scholarly journals AVALIAÇÃO DO USO DE RESÍDUOS DA CONSTRUÇÃO CIVIL RECICLADOS COMO AGREGADOS DO CONCRETO EM UM PÁTIO DE COMPOSTAGEM [ Evaluation of the use of recycled civil construction waste as concrete’s aggregates in a composting yard ]

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Alane Bessa Gualberto ◽  
Izabel Christina d'Almeida Duarte de Azevedo ◽  
Renan Monteiro Rodrigues Pereira
Keyword(s):  
Mechanical Characteristics ◽  
Recycled Aggregates ◽  
Economic Viability ◽  
Mechanical Resistance ◽  
Significant Saving ◽  
Construction Waste ◽  
Class A ◽  
Physical Chemical ◽  
Satisfactory Performance ◽  
Soil Cement

RESUMO: Os impactos ambientais, sociais e econômicos ocasionados pelos resíduos da construção civil (RCC) e sua inadequada disposição no ambiente, impõem a necessidade da adoção de soluções eficazes para a correta gestão desses resíduos. Neste trabalho, procurou-se avaliar a viabilidade de utilização de agregados reciclados de RCC classe A na construção de um pátio de compostagem piloto. Para isto, compararam-se seu desempenho e custo com pátios executados com concreto tradicional e solo-cimento. Os agregados reciclados foram analisados quanto às suas características físicas, químicas e mecânicas. Foram avaliados os parâmetros determinantes do processo de compostagem, a fim de averiguar possíveis influências dos agregados reciclados na degradação da matéria orgânica. O pátio com agregados reciclados quanto à estanqueidade e resistência mecânica não se mostrou adequado. O pátio executado com solo-cimento apresentou desempenho satisfatório. Quanto aos custos, a adoção de agregados reciclados proporcionou uma redução de 18,68% nos valores de implantação, comparado a um pátio em concreto tradicional, podendo representar uma economia significativa na obra de uma usina de triagem e compostagem. Porém, em relação ao pátio em solo-cimento, o pátio com agregados reciclados apresentou menor viabilidade econômica, visto que seu custo superou em 17,77% o do pátio em solo-cimento. Deste modo, identificaram-se os aspectos dos agregados reciclados que necessitam de melhoria para que estes se firmem como uma alternativa econômica e ambientalmente viável.ABSTRACT: The environmental, social and economic impacts caused by construction waste (CCW) and its inadequate disposal in the environment, require the adoption of effective solutions for the correct management of this waste. In this paper was try to evaluate the feasibility of using recycled aggregates of CCW class A in the construction of a pilot composting yard. For this, their performance and cost were compared with patios executed with traditional concrete and soil-cement. The recycled aggregates were analyzed for their physical, chemical and mechanical characteristics. The parameters determining the composting process were evaluated in order to investigate possible influences of the recycled aggregates on the degradation of organic matter. The yard with recycled aggregates for watertightness and mechanical resistance was not adequate. The yard with soil-cement presented satisfactory performance. In terms of costs, the adoption of recycled aggregates resulted in a 18.68% reduction in deployment values, compared to a traditional concrete yard, wich could represent a significant saving in the work of setting up a sorting and composting plant. However, in relation to the yard in soil-cement, the yard with recycled aggregates presented less economic viability, since its cost exceeded in 17.77% the patio in soil-cement. Thus, the aspects of the recycled aggregates that need improvement have been identified, so that these become an economical and environmentally viable alternative.

scholarly journals Assessing the Financial Feasibility of Slope Protection Through the use of Geocell With Recomposed of Infertile

2019 ◽  
Vol 7 (10) ◽  
pp. 745-760
Author(s):  
Dário Etsuro Haji Júnior ◽  
Estephison Montagnini e Silva ◽  
Igor Bezerra de Lima ◽  
David Barbosa de Alencar ◽  
Camily Murrieta Vasconcelos Oliveira Bezerra
Keyword(s):  
Granular Materials ◽  
Mechanical Characteristics ◽  
Load Capacity ◽  
Economic Viability ◽  
Economic Aspects ◽  
Financial Feasibility ◽  
Soil Cement ◽  
Small Load ◽  
Confinement System

Soils that have small load capacity need to have their mechanical characteristics improved in order to portray parameters that provide safety to the desired works. The geocells were developed to obtain a cellular confinement system used for reinforcement, protection and coating of slopes, similar to a beehive, which can be filled with soil, granular materials or concrete. However, the present work presents economic viability methods between the projected concrete and the geotextile. With the methodology, it was considered that the alternative use of geocell promoted savings of 35% compared to the projected concrete. The results indicated by tables that compose the projected concrete coatings and geocells were made available by the executing company. Finally, the method was applied to the soil-cement satisfactorily serving the execution, mechanical and economic aspects.

Obtaining and Characterisation of Starch-Based Edible Films Incorporating Honey, Propolis and Bee Bread

2019 ◽  
Vol 23 (2) ◽  
pp. 193-198
Author(s):  
Monica Mironescu ◽  
Laura Fratila ◽  
Alexandru Hupert ◽  
Ion Dan Mironescu
Keyword(s):  
Water Activity ◽  
Mechanical Characteristics ◽  
Edible Films ◽  
Ash Content ◽  
Colour Intensity ◽  
Sensorial Analysis ◽  
Physical Chemical ◽  
Control Film ◽  
Bee Bread

Abstract This research investigates the physical-chemical, sensorial and mechanical characteristics of starch-based edible films incorporating three types of bee hive products: honey, propolis and bee bread, in concentrations varying from 1% to 3%, reported to starch. The results indicates an increasing of films moisture, water activity, ash content and acidity, in the order: honey<propolis<bee bread, all values increasing with the increasing of hive products percentage into the control film; aw is remaining at very low values, under 0.4. Sensorial analysis indicated honey as the better suited for improving taste and flavour and bee bread for increasing colour intensity of the films; the sensorial characteristics are maintained during 30 days of films storage, in all cases. Compared with the control starch-based film (which is elastic, brittle and hard), the films containing 2% bee hive products are elasto-plastic and more resistant to penetration, the resistance increasing in the order: bee bread<propolis<honey.

scholarly journals Effects of increasing hydrophobicity on the physical-chemical and biological properties of a class A amphipathic helical peptide

2001 ◽  
Vol 42 (7) ◽  
pp. 1096-1104 ◽  
Author(s):  
Geeta Datta ◽  
Manjula Chaddha ◽  
Susan Hama ◽  
Mohamad Navab ◽  
Alan M. Fogelman ◽  
...  
Keyword(s):  
Biological Properties ◽  
Class A ◽  
Physical Chemical ◽  
Helical Peptide

A Study of the Chemical and Physical Characteristics of the Soils from the South of Piauí for Soil-Cement Brick Production

2016 ◽  
Vol 869 ◽  
pp. 112-115 ◽  
Author(s):  
Francisca Pereira de Araújo ◽  
Edson Cavalcanti Silva Filho ◽  
João Sammy Nery de Souza ◽  
Josy Anteveli Osajima ◽  
Marcelo Barbosa Furtini
Keyword(s):  
Organic Matter ◽  
Particle Density ◽  
Environmentally Friendly ◽  
Physical Characteristics ◽  
Chemical Characteristics ◽  
The South ◽  
Physical Chemical ◽  
Soil Cement ◽  
Made In

Soil-cement bricks are good examples of environmentally friendly products. This brick is the combination of soil with compacted cement with no combustion in its production. In this work the physical chemical characteristics of the soil from Piaui for producing this material were investigated. Samples of the soil were collected in three potteries from the county of Bom Jesus and pH analysis were carried out, as well as the rate of organic matter, texture, particle density, limits of liquidity and plasticity rates. The results have shown that the soils have acid tones (pH 5,49 a 6,11), which can be neutralized by adding cement, and organic matter percentages up to 1%. The samples have shown predominantly clay-rich textures with adequate plasticity limits, however, values of liquidity limits and particle density above recommended. Altogether, these soils tend to present viability concerning soil-cement brick production, provided that corrections with additives are made in order to minimize this effect.

scholarly journals Recovery of Zinc from Treatment of Spent Acid Solutions from the Pickling Stage of Galvanizing Plants

2021 ◽  
Vol 13 (1) ◽  
pp. 407
Author(s):  
Svetlana B. Zueva ◽  
Francesco Ferella ◽  
Valentina Innocenzi ◽  
Ida De Michelis ◽  
Valentina Corradini ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
State Of The Art ◽  
Zinc Content ◽  
Economic Viability ◽  
Acid Solutions ◽  
Physical Chemical ◽  
Galvanic Sludge ◽  
Valuable Metals

Typical methods for the treatment of waste pickling solutions include precipitation by alkaline reagents, most commonly calcium hydroxide. As a result, large volumes of galvanic sludge form, containing iron, calcium, sulphates, and a relatively small quantity of zinc (<20%), making Zn recovery not profitable. In summary, state-of-the-art Zn galvanization processes entail the loss of valuable metals and the irrational and expensive handling of spent pickling solutions (SPSs). The resulting conclusion is that there is room for a significant improvement in the way SPSs are treated, with the double goal of enhancing Zn galvanization methods’ economic viability and achieving a lesser impact on the environment’s processes. The experimental results show that it is possible to use SPS as a coagulant to treat the process wastewaters, kept separated, and added with sodium hydroxide. The results in obtaining precipitates with Zn contents higher than 40%, increasing the added advantage of making Zn recovery profitable. The results show the possibility of using SPS as a coagulant in the process of physical-chemical wastewater treatment and sodium hydroxide to obtain a precipitate with a zinc content of more than 40%.

Efficiency of Bio-Sourced Composites in Confining Recycled Aggregates Concrete

2022 ◽  
Author(s):  
Elhem Ghorbel ◽  
Mariem Limaiem
Keyword(s):  
Mechanical Behavior ◽  
Analytical Modeling ◽  
Mechanical Characteristics ◽  
Epoxy Polymer ◽  
Experimental Results ◽  
Confined Concrete ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Traditional System ◽  
Flax Fibers

This research investigates the efficiency of using Flax Fibers reinforced bio-sourced polymer by comparison to traditional system based on Carbone Fiber Reinforced Epoxy Polymer in order to confine recycled aggregates concrete. Four concrete formulations have been formulated by incorporating recycled aggregates from demolition waste (0%, 30%, 50% and 100%). An air-entraining agent was added to the formulations to achieve the level of 4% occluded air. The main objective is to discuss and to evaluate the effectiveness of confining them using bio-sourced composite by comparison to traditional ones. To hit this target, the developed approaches are both experimental and analytical. The first part is experimental and aimed to characterize the mechanical behavior of the materials: the composites used in the confining process the unconfined concrete (effect of incorporating recycled aggregates on the overall mechanical characteristics). We establish that bio-sourced composites are efficient in strengthening recycled aggregates concrete especially if they are air-entrained. The second part of this work is dedicated to analytical modeling of mechanical behavior of confined concrete with composite under compression based on Mander’s model. The input parameters of the model were modified to consider the rate of recycled aggregates incorporation. Comparison between experimental results and the modified Mandel’s Model is satisfactory.

scholarly journals Improving the Mechanical Strength of Dental Applications and Lattice Structures SLM Processed

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 905 ◽  
Author(s):  
Cosmin Cosma ◽  
Julia Kessler ◽  
Andreas Gebhardt ◽  
Ian Campbell ◽  
Nicolae Balc
Keyword(s):  
Tensile Strength ◽  
316L Stainless Steel ◽  
Mechanical Characteristics ◽  
Scanning Speed ◽  
Mechanical Resistance ◽  
Distribution Shape ◽  
Technological Defects ◽  
New Research ◽  
Dental Applications ◽  
Hatch Spacing

To manufacture custom medical parts or scaffolds with reduced defects and high mechanical characteristics, new research on optimizing the selective laser melting (SLM) parameters are needed. In this work, a biocompatible powder, 316L stainless steel, is characterized to understand the particle size, distribution, shape and flowability. Examination revealed that the 316L particles are smooth, nearly spherical, their mean diameter is 39.09 μm and just 10% of them hold a diameter less than 21.18 μm. SLM parameters under consideration include laser power up to 200 W, 250–1500 mm/s scanning speed, 80 μm hatch spacing, 35 μm layer thickness and a preheated platform. The effect of these on processability is evaluated. More than 100 samples are SLM-manufactured with different process parameters. The tensile results show that is possible to raise the ultimate tensile strength up to 840 MPa, adapting the SLM parameters for a stable processability, avoiding the technological defects caused by residual stress. Correlating with other recent studies on SLM technology, the tensile strength is 20% improved. To validate the SLM parameters and conditions established, complex bioengineering applications such as dental bridges and macro-porous grafts are SLM-processed, demonstrating the potential to manufacture medical products with increased mechanical resistance made of 316L.

scholarly journals Feasibility of Recycled Concrete in Pavements with Demolished Building Waste in UAE

2019 ◽  
Vol 8 (3) ◽  
pp. 5773-5778
Keyword(s):  
Cement Paste ◽  
Experimental Research ◽  
Commercial Buildings ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Construction Waste ◽  
Concrete Aggregates ◽  
Natural Aggregate ◽  
Natural Aggregates ◽  
Growing Population

The growing population has increased the demand for residential and commercial buildings. As a result of demolition of these buildings, lot of construction waste is generated. Most of these waste are non-biodegradable. When put into landfills, these waste pollute the land and harm the environment. Therefore, need of recycling these materials and using them is necessary. Concrete aggregates from demolished buildings can be reused to make concrete. However, its strength is immensely affected due to cement paste and mortar attached to it. Experimental research was carried out to determine how strengths of concrete made of natural aggregate, rejected concrete batch aggregate, aggregate from 8 years and 16 years old demolished buildings vary and also the feasibility of each. Different ratios of each type of recycled aggregates were taken along with the natural aggregates to determine how strength varies with change in ratio.

Physical, Chemical, and Mechanical Characteristics of Polyphenyl Ether

1967 ◽  
Vol 6 (2) ◽  
pp. 81-88 ◽  
Author(s):  
D. R. Wilson ◽  
W. A. Marshall ◽  
R. E. Dolle ◽  
R. J. Benzing
Keyword(s):  
Mechanical Characteristics ◽  
Polyphenyl Ether ◽  
Physical Chemical
Sign in / Sign up

Export Citation Format

Share Document