scholarly journals Effect of incorporation of grits waste on the densification behavior of soil-cement bricks

Cerâmica ◽  
2015 ◽  
Vol 61 (360) ◽  
pp. 414-419 ◽  
Author(s):  
F. B. Siqueira ◽  
J. N. F. Holanda

Abstract In the cellulose industry the Kraft process is widely used to produce cellulose. This process generates huge volumes of inorganic solid wastes, including the grits waste. In Brazil, the final disposal of this solid waste is of high economical and environmental interest. The present work assesses the influence of the addition of grits waste on the densification behavior of soil-cement bricks. The raw materials used were soil, Portland cement, and grits waste. Soil-cement bricks containing up to 30 wt.% grits waste in partial replacement of Portland cement were prepared by uniaxial pressing and cured for 28 days. The following technological properties were determined: water absorption, compressive strength, and durability. The microstructure was evaluated by scanning electron microscopy and X-ray diffraction. The experimental results indicated that the addition of grits waste influenced positively the densification behavior of the soil-cement bricks. Moreover, the grits waste could be incorporated into the soil-cement brick composition up to 20 wt.% as a partial replacement of Portland cement.

Geosciences ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 172 ◽  
Author(s):  
Michela Ricca ◽  
Giuseppe Paladini ◽  
Natalia Rovella ◽  
Silvestro Antonio Ruffolo ◽  
Luciana Randazzo ◽  
...  

This work focused on the study of decorated pottery dated back to the 16th century from the Roman archaeological site of Villa dei Quintili, a monumental complex located in the south-eastern part of Rome (Italy). A minero-petrographic and geochemical study was undertaken to analyse five archaeological samples in order to define textural features and raw materials used for their production, along with the chemical and physical composition of the superficial decorative glazed coatings. For this purpose, different analytical methods were used, such as polarising optical microscope (POM), X-ray diffraction (XRD), micro-Raman spectroscopy, X-Ray fluorescence (XRF), and electron microprobe analysis coupled with energy dispersive spectrometry (EMPA-EDS). The results of such a multidisciplinary approach allowed us to achieve important results crucial to recognise the shards as majolica of the Renaissance period, improving knowledge about manufacturing processes of these renowned painted ceramic artefacts.


2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Cleidson Carneiro Guimarães ◽  
Samile Raiza Carvalho Matos

RESUMO: O presente trabalho tem como objetivo principal avaliar a influência da cinza da casca de coco verde (CCCV) nas propriedades das argamassas no estado fresco e endurecido, a partir da substituição parcial do cimento Portland (CP) por cinza. Esta proposta surge da problemática ligada à destinação da casca do coco como resíduo urbano e agroindustrial e dos impactos ambientais provocados pela produção do cimento Portland. Para realização dessa pesquisa foram produzidas uma argamassa de referência e outras três argamassas com diferentes teores de substituição do CP por CCCV. Inicialmente, foi feita a caracterização dos materiais utilizados no trabalho e a análise de índice de pozolanicidade da cinza. Em seguida, foram feitas análises referenciais das propriedades das argamassas produzidas no estado fresco e no estado endurecido. A partir das análises pode-se perceber que a presença da cinza na argamassa influencia na trabalhabilidade, resistência mecânica e na durabilidade da argamassa e que a CCCV não possui potencial pozolânico. A adição de até 10% de CCCV substituindo o cimento Portland é viável.
 
 ABSTRACT: This study aims to evaluate the influence of ash green coconut shell (AGCS) on the properties of mortars in fresh and hardened, from the partial replacement of Portland cement (PC) by gray. This proposal arises from problems linked to the allocation of coconut shell as urban and agro-industrial waste and environmental impacts caused by the production of Portland cement. For this survey were produced a reference mortar and three mortars with different CP replacement levels by AGCS. Initially, it was the characterization of the materials used at work and ash pozzolanicity index analysis. Next, analyzes were made reference the properties of mortars produced in fresh and hardened state. From the analysis it can be seen that the ash presence in the mortar influences the workability, strength and durability of the mortar and the CCCV not have pozzolanic potential. The addition of up to 10% AGCS replacing the Portland cement is feasible.


2018 ◽  
Vol 761 ◽  
pp. 175-180 ◽  
Author(s):  
Janneth Torres Agredo ◽  
Sergio Gallego Restrepo ◽  
Fernando Álvarez Hincapié ◽  
Daniela Giraldo Alzate

In this work, the preliminary study about the use of secondary lead smelting slag (SLSS) as an addition to Portland cement is presented. SLSS is a waste from a Colombian secondary lead smelter. The chemical, physical and mineralogical characteristics of the raw materials were evaluated by X-ray fluorescence, particle size and X-ray diffraction. To assess the SLSS pozzolanic activity, the ASTM C618 standards were used. Additionally, cement pastes added with SLSS as Portland cement replacement in proportions of 0, 5, 10, 20 and 30% were prepared, to study the hydration process at 7, 14 and 28 of curing times. To determine the hydration products the technique of X-ray diffraction was used. Furthermore, the environmental test TCLP (Toxicity Characteristic Leaching Procedure) was performed in pastes with 28 days of curing time. Results showed that SLSS reported an index of pozzolanic activity of 87%, this value meets the standard (greater than 75%). The hydration process showed that since early curing time the waste presented a good reactivity. TCLP results satisfied the environmental standards. The outcomes showed that this waste could be used as a partial replacement of Portland cement.


Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 251
Author(s):  
Oana-Cătălina Mocioiu ◽  
Irina Atkinson ◽  
Ana-Maria Mocioiu ◽  
Simona Neagu ◽  
Robert Ruginescu ◽  
...  

One of the current research objectives is the development of new films for the conservation of glass heritage objects. The value of historical glass objects is given by the technology and raw materials used in production as well as their transparency and color. Their colors are correlated with oxide composition rich in transitional metals, which decrease resistance of corrosive agents from the atmosphere. In this paper, SiO2-ZnO gels have been designed to protect historical glass objects. The sol–gel method used to obtain gels is a powerful tool for functionalizing different materials. An important functionalization is the antibacterial activity. By applying a gel, the coated material is able to decrease the growth of bacteria. After deposition, some gels must be strengthened by heat treatment. The effect of ZnO content (10 mol% and 20 mol%) on the properties of the studied gels was investigated by Differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), and antibacterial tests. Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, and the halotolerant bacterium, Virgibacillus halodenitrificans, isolated from a salt crystal from Unirea mine, Slănic Prahova, Romania, were used. The gel Gel 2 (SiO2-ZnO (20 mol%)) showed the best properties.


KOVALEN ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 208-213
Author(s):  
Mukhtar Ghozali ◽  
Gamaliel Tanaka ◽  
Muhammad Misbahussalam ◽  
Tifa Paramitha

ZSM-5 is a synthetic zeolite which has a complex production process and is affected by operating conditions, such as temperature and time. In this study, synthesized ZSM-5 without template by hydrothermal method. An autoclave reactor was used for the hydrothermal process. The aim of this study was to investigate the effect of varied hydrothermal times of 24 and 48 hours with a hydrothermal temperature of 180oC on the characteristic of ZSM-5. The raw materials used were silica oxide and aluminum hydroxide as a source of silica and alumina. The synthesis results were characterized using X-Ray Diffraction (XRD). Based on XRD results, the best result was obtained in performed at 48 hours hydrothermal time indicating the formation of ZSM-5 material at the 22.2o position. The percentage crystallinity of the sample at the hydrothermal time of 48 hours was 51.3%.


2014 ◽  
Vol 1077 ◽  
pp. 135-138
Author(s):  
Luiz Oliveira Veriano dalla Valentina ◽  
Marilena Valadares Folgueras ◽  
Wanessa Rejane Knop ◽  
Maria Cristina Pacheco do Nascimento ◽  
Glaucia Aparecida Prates

As the raw materials used in the ceramic materials manufacturing are natural, it is important to use them as a alternative materials, thus decreasing the elements demand taken from nature. This paper aims the characterization of foundry solid powder exhaust from a brazilian company located in Joinville - SC as an alternative raw material for ceramic coating by X-ray diffraction (XRD), thermal analysis (DSC) and thermogravimetric (TG). The dust depletion is caused in the manufacturing mold sand process, when the bentonita (clay), silica sand and coal during the metal parts production are mixed in green sand production. The raw materials were characterized through X-ray diffraction (XRD), thermal (DSC) and thermogravimetric analisys (TG). The atomized powder thermogravimetric analysis curve shows three intervals associated with the mass loss and it is typical of clay commercial application.


2016 ◽  
Vol 869 ◽  
pp. 191-194
Author(s):  
Carolina del Roveri ◽  
R.A. Cunha ◽  
Antenor Zanardo ◽  
Letícia Hirata Godoy ◽  
Maria Margarita Torres Moreno ◽  
...  

The Santa Gertrudes ́ Ceramic Polo is the Brazilian region with national and international prominence in the manufacturing of ceramic tiles. Some raw materials used by ceramic industry and coatings industries in this region were characterized in terms of chemical-mineralogical and microscopic view, in order to promote the best technological characterization of them. For this, chemical analysis of major elements and trace X-ray diffraction and microscopic analysis by SEM, TEM and Electron microprobe were performed by ICP-MS. The results showed that the raw materials commonly referred to as "clays" are actually constituted by various mineral phases, which directly influence the properties of the same ceramics. Also showed that, by virtue of this constitution, different formulations can be developed, using the best raw materials found in the region of Santa Gertrudes, SP.


2012 ◽  
Vol 32 (5) ◽  
pp. 810-821 ◽  
Author(s):  
Débora C. G. de Oliveira ◽  
Michelle S. Rodrigues ◽  
Sérgio F. dos Santos ◽  
Holmer Savastano Junior

The deep bedding is a swine alternative production, especially in the finishing phase, whose byproduct can be recycled, reducing the environmental impact. The objectives of this study were to characterize the ash coming from the controlled burning of the swine deep bedding (SDBA) based on rice husk, and to evaluate their performance in composites as a partial substitute for Portland cement (PC). To measure the differences between SDBA and rice husk ash (RHA) as a reference, we have characterized: particle size distribution, real specific density, x-ray diffraction, electrical conductivity, scanning electron microscopy, chemical analysis and loss on ignition. Samples were prepared for two experimental series: control, and another one with the partial replacement of 30% of SDBA in relation to the mass of the Portland cement. According to the results obtained for physical and mechanical characterization, the composites with SDBA can be used as a constructive element in the rural construction.


2010 ◽  
Vol 74 (4) ◽  
pp. 747-771 ◽  
Author(s):  
C. Rathossi ◽  
P. Tsolis-Katagas ◽  
C. Katagas

AbstractA ‘metamorphic vermiculite’-like phase was identified in Ca-rich ancient ceramic sherds from excavations in NW Peloponnese, Greece. Archaeometric investigations have shown that the raw materials used in the production of ancient ceramics were derived from local Plio-Pleistocene sediments. Analysis by X-ray diffraction and scanning electron microscopy-energy dispersive spectroscopy showed that ‘metamorphic vermiculite’ is a common constituent phase of these sediments occurring in three texturally different types: as interstratified white mica-chlorite and chlorite-vermiculite, and white mica-(white mica-chlorite) stacks. In an attempt to elucidate the thermal transformation of ‘metamorphic vermiculite’ present in the calcareous raw materials, we produced experimental ceramics made from these local raw materials and fired them at 700, 750, 850, 950 and 1050°C in a static air furnace. The mixed-layered chlorite-vermiculite was transformed completely at ∼800°C contributing to the formation of new high-Tminerals. The two other types of ‘metamorphic vermiculite’ retain their original lath-like shape up to 1050°C and only a few crystals show that they have undergone complete transformation at this temperature. In the latter crystals, numerous nanocrystals were formed sub-parallel to the former cleavages of ‘metamorphic vermiculite’ pseudomorphs, suggesting their contribution to the nucleation of high-Tminerals (i.e. ferrian aluminian diopside, spinel, Fe oxides) by reactions with the available CaO. It is suggested that the firing conditions (i.e. maximum reaction temperature of 1050°C, reaction time of 1 h, oxygen atmosphere) which promote disequilibrium reactions, and the greater contribution of the white mica constituent against chlorite in some of the initial structures of ‘metamorphic vermiculite’ may be responsible for the delay of its thermal decomposition at 1050°C.


2012 ◽  
Vol 730-732 ◽  
pp. 94-99 ◽  
Author(s):  
Maria Margarida Rolim Augusto Lima ◽  
L.F.C. Braz ◽  
Regina da Conceição Corredeira Monteiro ◽  
J.P. Veiga

Phosphogypsum (PG) is a pollutant residue resulting from the production of phosphoric acid in the phosphated fertilizers industry. About 180 millions of tons of PG are generated worldwide per year, which originates storage problems because of the environmental restrictions and the high costs of storage spaces. Taking into account the mineralizer properties of PG it has been studied a way to valorize this residue as an alternative material in the production of Portland cement clinker. The PG and the raw-materials (limestone, marl, sand and iron oxide) were chemical, mineralogical and thermally characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) and differential thermal analysis and termogravimetric analysis (DTA/TGA). After milling, the phosphogypsum was mixed with the raw-materials in different amounts up to 10% weight. The raw mixtures were submitted to two types of firing schedules, heating up to 1500°C without any holding time or heating up to 1350°C and holding for 20 minutes. After firing, the clinkers were analyzed by optical microscopy, milled and characterized in terms of chemical and mineralogical compositions. The clinkers were used to produce cement mortar according to NP EN 196-1 standard. The resultant test specimens were mechanically tested at 2 and 28 days according to the same standard. The obtained results show a reduction of about 140°C in the clinkerization temperature, when a raw mixture with 5% phosphogypsum was used. Standard clinkers, without phosphogypsum addition, which were fired at 1500°C, originated test specimens with a compressive strength of 48.1MPa at 28 days. Test specimens produced with clinker containing 5% phosphogypsum present higher compressive strength values at 28 days, being 55.1MPa for clinkers produced at 1500°C, and 49.4 MPa for clinkers produced at 1350°C.


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