scholarly journals Use of glass waste in the production of metakaolin-based geopolymer submitted to room temperature and thermal curing

2022 ◽  
Vol 22 (1) ◽  
pp. 147-160
Author(s):  
Cristiane do Bom Conselho Sales Alvarenga ◽  
Rosemary do Bom Conselho Sales ◽  
Rodrigo Barreto Caldas ◽  
Paulo Roberto Cetlin ◽  
Maria Teresa Paulino Aguilar
Keyword(s):  
Mechanical Performance ◽  
Infrared Region ◽  
Raw Material ◽  
Resonance Spectroscopy ◽  
Thermal Curing ◽  
Specific Mass ◽  
Glass Waste ◽  
Alkaline Activation ◽  
Efficient Alternative ◽  
The Fourier Transform

Abstract Metakaolinis the principal raw material utilized in the synthesis of geopolymers, although its ratio of silica and alumina contents is not ideal. Normally, the SiO2 content is adjusted with the use of silicates present in the activating solution. An eco-efficient alternative would be the use of glass waste as an additional source of silica.This work evaluates the efficiency of the alkaline activation of metakaolin, using potassium hydroxide and silicate, with and without the substitution of 12.5% of metakaolin by microparticles of glass. The efficiency of the alkaline activation was evaluated by X ray diffractometry, spectroscopy in the infrared region with the Fourier transform, nuclear magnetic resonance spectroscopy of 27Al and 29Si, specific mass and compressive strength. The results indicate the occurrence of geopolymerization with and without the use of glass waste. It was observed that the substitution of 12.5% favors the mechanical performance of the compounds at 28 days, with increases by 37% and 47% in the mechanical strength of the material with thermal curing and ambient temperature curing, respectively.

scholarly journals Crushed Bricks: Demolition Waste as a Sustainable Raw Material for Geopolymers

2021 ◽  
Vol 13 (14) ◽  
pp. 7572
Author(s):  
Gigliola D’Angelo ◽  
Marina Fumo ◽  
Mercedes del Rio Merino ◽  
Ilaria Capasso ◽  
Assunta Campanile ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Building Materials ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Construction Material ◽  
Raw Material ◽  
The European Union ◽  
Total Energy Consumption ◽  
Demolition Waste ◽  
Crushed Brick

Demolition activity plays an important role in the total energy consumption of the construction industry in the European Union. The indiscriminate use of non-renewable raw materials, energy consumption, and unsustainable design has led to a redefinition of the criteria to ensure environmental protection. This article introduces an experimental plan that determines the viability of a new type of construction material, obtained from crushed brick waste, to be introduced into the construction market. The potential of crushed brick waste as a raw material in the production of building precast products, obtained by curing a geopolymeric blend at 60 °C for 3 days, has been exploited. Geopolymers represent an important alternative in reducing emissions and energy consumption, whilst, at the same time, achieving a considerable mechanical performance. The results obtained from this study show that the geopolymers produced from crushed brick were characterized by good properties in terms of open porosity, water absorption, mechanical strength, and surface resistance values when compared to building materials produced using traditional technologies.

scholarly journals Mechanical Properties of Boehmeria nivea Natural Fabric Reinforced Epoxy Matrix Composite Prepared by Vacuum-Assisted Resin Infusion Molding

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1311 ◽  
Author(s):  
Fabio da Costa Garcia Filho ◽  
Fernanda Santos da Luz ◽  
Lucio Fabio Cassiano Nascimento ◽  
Kestur Gundappa Satyanarayana ◽  
Jaroslaw Wieslaw Drelich ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Volume Fraction ◽  
Natural Fibers ◽  
Ramie Fiber ◽  
Resin Infusion ◽  
Lignocellulosic Fibers ◽  
Boehmeria Nivea ◽  
Fabric Composites ◽  
Epoxy Matrix Composite ◽  
Efficient Alternative

Natural lignocellulosic fibers and corresponding fabrics have been gaining notoriety in recent decades as reinforcement options for polymer matrices associated with industrially applied composites. These natural fibers and fabrics exhibit competitive properties when compared with some synthetics such as glass fiber. In particular, the use of fabrics made from natural fibers might be considered a more efficient alternative, since they provide multidirectional reinforcement and allow the introduction of a larger volume fraction of fibers in the composite. In this context, it is important to understand the mechanical performance of natural fabric composites as a basic condition to ensure efficient engineering applications. Therefore, it is also important to recognize that ramie fiber exhibiting superior strength can be woven into fabric, but is the least investigated as reinforcement in strong, tough polymers to obtain tougher polymeric composites. Accordingly, this paper presents the preparation of epoxy composite containing 30 vol.% Boehmeria nivea fabric by vacuum-assisted resin infusion molding technique and mechanical behavior characterization of the prepared composite. Obtained results are explained based on the fractography studies of tested samples.

Effect of Trivalent Metal Cations on the Properties of LDHs Supercapacitors Prepared from Electroplating Sludge

2021 ◽  
Vol 1035 ◽  
pp. 1089-1095
Author(s):  
Jin Yun Zhu ◽  
Tao Jun Li ◽  
Li Chen ◽  
Tian Bao Liu ◽  
Xiu Ling Yan
Keyword(s):  
Acid Leaching ◽  
Metal Cations ◽  
Raw Material ◽  
Trivalent Metal ◽  
Specific Mass ◽  
Inhibition Effect ◽  
Electroplating Sludge ◽  
Leaching Solution ◽  
Supercapacitor Performance ◽  
Double Hydroxides

Trivalent metal cations are the basic composition of Layered Double Hydroxides (LDHs), however, the effect of metal cations on the supercapacitor performance of LDHs prepared from electroplating sludge has not been reported. In the present study the acid leaching solution of electroplating sludge was used as raw material, and Cr, Fe, Al and other common metal cations were added into the precursors to investigate the effect of trivalent metal cations on the supercapacitor performance of LDHs prepared from electroplating sludge. The experimental results show that the three kinds of metal cations can inhibit the specific mass capacitance of LDHs, and the sequence of inhibition effect is Fe < Al < Cr. This experiment is expected to provide some references for the resource utilization of electroplating sludge.

scholarly journals Synthesis and Characterization of Nanofiber of Oxidized Cellulose from Nata De Coco

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Ditpon Kotatha ◽  
Supitcha Rungrodnimitchai
Keyword(s):  
Reaction Time ◽  
Reaction Times ◽  
Degree Of Polymerization ◽  
Raw Material ◽  
Gravimetric Analysis ◽  
Oxidized Cellulose ◽  
Carboxyl Content ◽  
Cellulose Structure ◽  
Nanofibrous Structure ◽  
The Fourier Transform

Oxidized cellulose (OC) nanofiber was successfully prepared from the dry sheet of Nata De Coco (DNDC) using the mixture system of HNO3/H3PO4–NaNO2for the first time. The carboxyl content of the OC was investigated at different conditions (HNO3/H3PO4ratios, reaction times, and reaction temperatures). The results revealed that the carboxyl content of the OC increased along with the reaction time, which yielded 0.6, 14.8, 17.5, 20.9, 21.0, and 21.0% after 0, 6, 12, 36, and 48 hours, respectively. The reaction yields of the OC ranged between 79% and 85% when using HNO3/H3PO4ratio of 1 : 3, 1.4% wt of NaNO2at 30°C at different reaction times. From the structural analysis, the OC products showed a nanofibrous structure with a diameter of about 58.3–65.4 nm. The Fourier transform infrared spectra suggested the formation of carboxyl groups in the OC after oxidation reaction. The crystallinity and crystalline index decreased with an increase of reaction time. The decrease of crystallinity from oxidation process agreed with the decrease of degree of polymerization from the hydrolysis ofβ-1,4-glycosidic linkages in the cellulose structure. The thermal gravimetric analysis results revealed that the OC products were less thermally stable than the raw material of DNDC. In addition, the OC products showed blood agglutinating property by dropping blood on the sample along with excellent antibacterial activity.

Development of Nano Modified Eco-Friendly Green Binders for Sustainable Construction Applications

2019 ◽  
Vol 24 ◽  
pp. 25-36 ◽  
Author(s):  
Hamada Shoukry
Keyword(s):  
Water Absorption ◽  
Mechanical Performance ◽  
Raw Material ◽  
Sustainable Construction ◽  
Partial Replacement ◽  
Cementitious Composites ◽  
Water Absorption Coefficient ◽  
Compressive And Flexural Strengths ◽  
Cement Manufacturing

Cement manufacturing, which is partially responsible for environmental and health risks as well as the greenhouse gas emissions, is a binder industry that needs energy and raw material. To decrease the needing, this study develops nano-modified eco-friendly cementitious composites including industrial solid wastes and/or by-products. For this purpose, ordinary Portland cement (OPC) was partially replaced with 70 wt% of fly ash (FA), Nano metakaolin (NMK) was incorporated at a rate of 2, 4, 6, 8, 10, 12 and 14 % as partial replacement by weight of FA to take advantage of the great role of nano materials in improving the mechanical and physical properties of cement based materials. Compressive strength, flexural strength, and capillary water absorption coefficient have been studied at 28 days of curing according to the international ASTM standards. Differential scanning calorimeter (DSC) was used to study the phase composition/decomposition. The microstructure characteristics of the hardened samples were investigated by scanning electron microscope (SEM) equipped with energy dispersive analytical x-ray unit (EDAX). The results revealed that the partial replacement of cement by 70% of FA has reduced both compressive and flexural strengths by about 45% in addition; the water absorption has been increased by about 175% as compared to the OPC. The replacement of FA by different amounts of NMK compensate for the loss in strength by about 75%. Furthermore, NMK has considerably improved the microstructure and reduced the water absorption by 86%. The study concluded that, it is possible to substitute 70% of the weight of the cement in the production of eco-friendly cementitious composites with improved mechanical performance attaining 88% of the corresponding performance of the hydrated OPC. The developed composites can be considered as green binders and recommended for various applications in construction industry.

scholarly journals Laser-based additively manufactured polymers: a review on processes and mechanical models

2020 ◽  
Vol 56 (2) ◽  
pp. 961-998
Author(s):  
Roberto Brighenti ◽  
Mattia Pancrazio Cosma ◽  
Liviu Marsavina ◽  
Andrea Spagnoli ◽  
Michele Terzano
Keyword(s):  
Process Parameters ◽  
Mechanical Performance ◽  
Selective Laser Sintering ◽  
Theoretical Models ◽  
Raw Material ◽  
Laser Source ◽  
Mechanical Resistance ◽  
Layer By Layer ◽  
Influence Of Process Parameters ◽  
Mechanical Models

Abstract Additive manufacturing (AM) is a broad definition of various techniques to produce layer-by-layer objects made of different materials. In this paper, a comprehensive review of laser-based technologies for polymers, including powder bed fusion processes [e.g. selective laser sintering (SLS)] and vat photopolymerisation [e.g. stereolithography (SLA)], is presented, where both the techniques employ a laser source to either melt or cure a raw polymeric material. The aim of the review is twofold: (1) to present the principal theoretical models adopted in the literature to simulate the complex physical phenomena involved in the transformation of the raw material into AM objects and (2) to discuss the influence of process parameters on the physical final properties of the printed objects and in turn on their mechanical performance. The models being presented simulate: the thermal problem along with the thermally activated bonding through sintering of the polymeric powder in SLS; the binding induced by the curing mechanisms of light-induced polymerisation of the liquid material in SLA. Key physical variables in AM objects, such as porosity and degree of cure in SLS and SLA respectively, are discussed in relation to the manufacturing process parameters, as well as to the mechanical resistance and deformability of the objects themselves. Graphic abstract

Facile Fabrication of Porous and Hydrophilic Polystyrene Membranes Using Recycled Waste

2020 ◽  
Vol 1008 ◽  
pp. 39-46
Author(s):  
Mostafa Khaled ◽  
H. Noby ◽  
W.A. Aissa ◽  
Ahmed Hassan El-Shazly
Keyword(s):  
Membrane Surface ◽  
High Impact ◽  
Raw Material ◽  
Dimethyl Formamide ◽  
High Concentration ◽  
Water Contact ◽  
Polymer Waste ◽  
High Impact Polystyrene ◽  
The Fourier Transform ◽  
Polystyrene Waste

Micro-porous hydrophilic membranes were successfully fabricated using polystyrene waste by phase inversion casting. Four concentrations (20, 25, 30, and 35 wt%) of recycled high-impact polystyrene (HIPS-R) in N, N-dimethyl formamide (DMF) solution were employed to prepare the membranes. The effect of polystyrene concentration on the characteristics of the different membranes was thoroughly studied. Based on the Fourier transform infrared spectroscopy (FTIR) results, the chemical composition of HIPS-R was analogous to that of pure high-impact polystyrene HIPS raw material of the previous studies. Also, field-emission scanning electron microscopy (FESEM) was employed to study the morphology and porosity of the prepared membranes. The membranes cross-section showed a sponge structure with longitudinal macro voids. The solid walls around these voids have a sponge-like structure, especially for high concentration polystyrene membranes. Furthermore, the number of pores into the membrane surface decreased with the increase of polystyrene concentration. The membranes surface pores size was ranged from 150 nm to 550 nm with the different used concentrations. Water contact angle (CA) of the prepared membrane's surface were measured. All the measured CA of the prepared membranes, except the 35 wt% showed CA of 91o, showed a hydrophilic behavior. Thus, the results suggest effective membranes could be obtained using recycled polystyrene. And then, solve the polymer waste accumulation problem in parallel with help in drinking water crisis solution.

Effect of unrefined crude glycerol composition on the properties of polyurethane foams

2017 ◽  
Vol 54 (3) ◽  
pp. 633-649 ◽  
Author(s):  
Nuno V Gama ◽  
Belinda Soares ◽  
Carmen SR Freire ◽  
Rui Silva ◽  
Artur Ferreira ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Crude Glycerol ◽  
Mechanical Performance ◽  
Methyl Esters ◽  
Thermomechanical Properties ◽  
Polyurethane Foams ◽  
Raw Material ◽  
Two Samples ◽  
Pre Treatment ◽  
The Impact

The aim of this study is to evaluate the possibility of using unrefined crude glycerol (CG), a byproduct of the biodiesel industry, in the production of polyurethane foams. In order to assess the suitability of this raw material for the production of polyurethane foams, two samples of crude glycerol with different compositions in glycerol, fatty acids, and methyl esters were used directly, without any pretreatment or purification. Additionally, one of these samples was also submitted to a pre-treatment step in order to evaluate the advantage of purifying the raw material and, for comparison, pure glycerol was also used to prepare polyurethane foams. Both chemical and structural characterizations of the produced foams, as well as the thermomechanical properties determined, showed that unrefined crude glycerol is a suitable ecopolyol for the production of polyurethane foams. Although the presence of fatty acids and esters affects their mechanical performance, this issue can be explored to tune the properties of the ensuing polyurethane foams. Furthermore, the evaluation of the impact of using unrefined CG on the sustainability of polyurethane foams production yielded promising results.

Sewage Sludge as Raw-Material in Asphalt Mixtures

2013 ◽  
Vol 664 ◽  
pp. 638-643 ◽  
Author(s):  
Maria del Pilar Durante Ingunza ◽  
Olavo Francisco dos Santos Júnior ◽  
Sayonara Andrade Medeiros
Keyword(s):  
Mechanical Performance ◽  
Environmental Parameters ◽  
Empty Space ◽  
Asphalt Mixtures ◽  
International Standards ◽  
Raw Material ◽  
Air Voids ◽  
The One ◽  
Consequent Increase ◽  
Space Volume

The aim of this study is to assess the volumetric and mechanical behavior of concrete asphalt mixtures, using natural sludge as a partial substitute for the tiny aggregate and calcined sludge as filler. This assessment was performed based on technical and environmental parameters, using laboratory tests obeying current Brazilian norms, according to international standards. The addition of natural sludge to the mixtures has increased stability, increased air voids contents of the mixtures. The addition has compromised mixture adhesiveness. With respect to the addition of calcined sludge to the mixtures, the mixtures with calcined sludge displayed the same behavior as those with cement. It was observed decrease in empty space volume of the mixtures and consequent increase in empty space-bitumen relation and increased stability. The mixture addition of natural sludge that has the best mechanical and volumetric performance is the one with 7.5% of natural sludge in the granulometric composition of the mixture. The mixture with 1% of calcined sludge had the best volumetric and mechanical performance.

scholarly journals Use of basaltic waste as red ceramic raw material

Cerâmica ◽  
2016 ◽  
Vol 62 (362) ◽  
pp. 157-162 ◽  
Author(s):  
T. M. Mendes ◽  
G. Morales ◽  
P. J. Reis
Keyword(s):  
Size Distribution ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Raw Material ◽  
Metropolitan Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Evaluation ◽  
Firing Shrinkage ◽  
Physical And Chemical

Abstract Nowadays, environmental codes restrict the emission of particulate matters, which result in these residues being collected by plant filters. This basaltic waste came from construction aggregate plants located in the Metropolitan Region of Londrina (State of Paraná, Brazil). Initially, the basaltic waste was submitted to sieving (< 75 μm) and the powder obtained was characterized in terms of density and particle size distribution. The plasticity of ceramic mass containing 0%, 10%, 20%, 30%, 40% and 50% of basaltic waste was measured by Atterberg method. The chemical composition of ceramic formulations containing 0% and 20% of basaltic waste was determined by X-ray fluorescence. The prismatic samples were molded by extrusion and fired at 850 °C. The specimens were also tested to determine density, water absorption, drying and firing shrinkages, flexural strength, and Young's modulus. Microstructure evaluation was conducted by scanning electron microscopy, X-ray diffraction, and mercury intrusion porosimetry. Basaltic powder has similar physical and chemical characteristics when compared to other raw materials, and contributes to ceramic processing by reducing drying and firing shrinkage. Mechanical performance of mixtures containing basaltic powder is equivalent to mixtures without waste. Microstructural aspects such as pore size distribution were modified by basaltic powder; albite phase related to basaltic powder was identified by X-ray diffraction.

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