scholarly journals Study of the expansion of cement mortars manufactured with Ladle Furnace Slag LFS

2019 ◽  
Vol 69 (334) ◽  
pp. 183
Author(s):  
A. Rodríguez ◽  
I. Santamaría-Vicario ◽  
V. Calderón ◽  
C. Junco ◽  
J. García-Cuadrado
Keyword(s):  
High Temperatures ◽  
Environmental Conditions ◽  
Raw Materials ◽  
Construction Materials ◽  
Cement Matrix ◽  
Cement Mortars ◽  
Experimental Process ◽  
Pre Treatment ◽  
Adverse Environmental Conditions ◽  
The Stability

Industrial by-products generated in the steel manufacturing are successfully used as raw materials in the production of construction materials. However, steel slags, due to their nature and composition, can cause undesirable side-effects in mortars and concretes. The reactive components of LFS and EAFS can affect the stability of the cement matrix. This situation may be prevented by an adequate pre-treatment of slag stabilization and a study of the possible reactions within its mineralogical components, to ensure the stability of the slag over time. In this work, an experimental process is shown to evaluate the behaviour of LFS under adverse environmental conditions when used as aggregates in the manufacture of cement mortars for masonry, such as the presence of humidity, high temperatures (80°C) and possible alkali-silica and alkali-silicate reactions. The results show an acceptable behaviour under normal environmental conditions (20°C). However, the formation crystalline acicular structures were observed under high temperatures (80°C) and in the presence of humidity, which degraded the internal structure of the mortars manufactured with LFS.

Addition of Calcareous Quarry to Bricklaying Mortars - Analysis of the Properties in Fresh State

2010 ◽  
Vol 636-637 ◽  
pp. 1286-1291
Author(s):  
M. Luiza Lopes O. Santos ◽  
Antonio Eduardo Martinelli ◽  
M.A.F. Melo ◽  
D.M.A. Melo
Keyword(s):  
Construction Industry ◽  
Raw Materials ◽  
Tap Water ◽  
Construction Materials ◽  
Volume Ratio ◽  
Hydrated Lime ◽  
Specific Mass ◽  
River Sand ◽  
Cement Mortars ◽  
Fresh State

One of the major current environmental concerns is the excessive or inefficient consumption of non-renewable natural resources. The construction industry is one of the largest consumers of natural raw materials, playing an important role in the degradation of the environment. Recycling and reusing are concepts that can be effectively applied in the formulation of construction materials, especially mortars. In particular, calcareous quarry can replace, at least to some extent, the cement used in the composition of bricklaying mortars. The objective of this study was to prepare and characterize mortars containing calcareous quarry. The mortars were prepared using Portland CP II F – 32 cement, CH I hydrated lime, river sand and tap water. Different concentrations of residues, ranging from 5 to 30% were used to replace the cement. Mortars with volume ratio of 1:0.5:4.5, commonly used in bricklaying structural masonry, were evaluated. The water to cement ration was set to 1.45. The residue used was fully characterized to determine their specific mass, unitary mass, particle size distribution and morphology, and composition. The mortars were characterized both in their fresh and the results compared to those obtained from a residue-free composition. The results showed that the use of calcareous quarry partially replacing the cement did not significantly affect the performance of the mortars. Compositions containing up to 30% of calcareous quarry can be classified according to NBR 13281 (ABNT, 2005) as bricklaying mortars, and can be used by the construction industry.

Degradation observations of encapsulated planar CH3NH3PbI3 perovskite solar cells at high temperatures and humidity

2015 ◽  
Vol 3 (15) ◽  
pp. 8139-8147 ◽  
Author(s):  
Yu Han ◽  
Steffen Meyer ◽  
Yasmina Dkhissi ◽  
Karl Weber ◽  
Jennifer M. Pringle ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Temperatures ◽  
Environmental Conditions ◽  
Perovskite Solar Cells ◽  
The Stability

The stability of encapsulated planar-structured CH3NH3PbI3 (MAPbI3) perovskite solar cells (PSCs) was investigated under various simulated environmental conditions.

scholarly journals Pinus spp. Somatic Embryo Conversion under High Temperature: Effect on the Morphological and Physiological Characteristics of Plantlets

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1181
Author(s):  
Antonia Maiara Marques do Nascimento ◽  
Priscila Alves Barroso ◽  
Naysa Flavia Ferreira do Nascimento ◽  
Tomás Goicoa ◽  
María Dolores Ugarte ◽  
...  
Keyword(s):  
High Temperatures ◽  
Environmental Conditions ◽  
Somatic Embryos ◽  
Pinus Halepensis ◽  
Radiata Pine ◽  
Planted Forests ◽  
Somatic Plants ◽  
Adverse Environmental Conditions ◽  
Process Of Se ◽  
Pinus Spp

Climatic variations in the current environmental scenario require plants with tolerance to sudden changes in temperature and a decrease in water availability. Accordingly, this tolerance will enable successful plantations and the maintenance of natural and planted forests. Consequently, in the last two decades, drought tolerance and high temperatures in conifers have been an important target for morphological, physiological, and epigenetic studies. Based on this, our research team has optimized different stages of somatic embryogenesis (SE) in Pinus spp. improving the success of the process. Through this method, we can obtain a large amount of clonal material and then analyze the somatic plants under different conditions ex vitro. The analysis of the morphological and physiological parameters in somatic embryos (ses) and plants with different tolerances to abiotic stress can provide us with valuable information about the mechanisms used by plants to survive under adverse environmental conditions. Thus, the objective of this work was to evaluate the influence of high temperatures (23, 40, 50, and 60 °C, after 12 weeks, 90, 30, 5 min, respectively) on the morphology of somatic embryos obtained from Pinus radiata D.Don (Radiata pine) and Pinus halepensis Mill. (Aleppo pine). In addition, we carried out a physiological evaluation of the somatic plants of P. radiata submitted to heat and water stress in a greenhouse. We observed that the number of somatic embryos was not affected by maturation temperatures in both species. Likewise, P. radiata plants obtained from these somatic embryos survived drought and heat stress in the greenhouse. In addition, plants originating from embryonal masses (EMs) subjected to high maturation temperature (40 and 60 °C) had a significant increase in gs and E. Therefore, it is possible to modulate the characteristics of somatic plants produced by the manipulation of environmental conditions during the process of SE.

scholarly journals Evaluation of Copper Leaching for Subsequent Recovery from the Waste Dumps of the Linares Mining District and Their Use for Construction Materials

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1328
Author(s):  
Juan María Terrones-Saeta ◽  
Jorge Suárez-Macías ◽  
Ana María Castañón ◽  
Francisco Antonio Corpas-Iglesias
Keyword(s):  
Sulfuric Acid ◽  
Raw Materials ◽  
Construction Materials ◽  
Well Being ◽  
Mining District ◽  
Bituminous Mixtures ◽  
Bitumen Emulsion ◽  
Waste Dumps ◽  
The Stability ◽  
Sulfuric Acid Solutions

The development of the population’s well-being involves the use of different raw materials. However, metallic elements such as copper are currently scarce due to their intensive use in different sectors. Therefore, new sources of raw materials that provide these elements, are of lower cost, and use waste for their extraction must be sought. For this reason, in this research, different waste dumps of the mining district of Linares (Spain) are studied to evaluate the existence of recoverable copper by hydrometallurgical techniques. The material from the waste dump selected as potentially viable is leached with different sulfuric acid solutions (0.25, 0.5, 1, and 2 mol) and at different times, obtaining copper concentrations usable for subsequent hydrometallurgical processes. In addition, in order to develop an environmental hydrometallurgy, the leach waste is characterized, and bituminous mixtures are made with it. The results of the present investigation showed that it was possible to recover 80% of the copper in the waste dumps of the Linares mining district with 1 and 2 mol solutions of sulfuric acid. At the same time, the waste from the leaching process was found to be suitable for use as an aggregate in bituminous mixtures. Therefore, bituminous mixtures were conformed, and it was obtained that the optimum percentage of bituminous emulsion was 6.95% for the proposed granulometry. This emulsion percentage, which corresponds to a residual bitumen percentage of 4.17%, showed particle loss test results of 14% and 18% after immersion. In addition, the stability test values for the Marshall test with the above-mentioned bitumen emulsion percentage and leaching waste showed a stability of 8.99 KN. This fact demonstrates the quality of the bituminous mixture made with the leaching waste for use in bituminous mixtures. Consequently, it can be affirmed that in the present investigation, a significant percentage of copper has been extracted from the waste dumps of the mining district of Linares (Spain) and that the waste after processing can be used in bituminous mixtures, there being a closed cycle of materials in which no waste is produced.

Immobilization Science of Cement Systems

MRS Bulletin ◽  
1993 ◽  
Vol 18 (3) ◽  
pp. 66-71 ◽  
Author(s):  
D.E. Macphee ◽  
F.P. Glasser
Keyword(s):  
Raw Materials ◽  
Low Cost ◽  
Construction Materials ◽  
Cement Matrix ◽  
Physical Damage ◽  
Slaked Lime ◽  
History Of ◽  
History Of Use ◽  
Roman Concrete ◽  
Calcined Kaolin

Portland cement and Ca(OH)2, “slaked lime,” are representative of a family of materials that have conceptual and practical advantages as matrices for the immobilization of wastes. These are relatively proven construction materials with an extensive history of use in various ground-water regimes, and in various climates. The raw materials are widely available and they exhibit a reasonable amount of resistance to physical damage and attrition. They are also durable. Although modern Portland cements are only about 150 years old, numerous examples of Roman concrete made from slaked lime and volcanic pozzolanic ash survive; the Pantheon in Rome (circa A.D. 300) continues in regular use.Satisfactory immobilization matrices can also be formed by incorporating other artificial waste materials, e.g. coal combustion fly ash, blast furnace slag, and natural materials such as calcined kaolin or siliceous volcanic ashes containing glass and zeolites. These materials react with Ca(OH)2 and cement to become an integral part of a cement matrix. Thus one waste (ash, slag) can be used to help immobilize another, and may actually improve the retentive capacity of a cementitious matrix.Since cements require water to harden, they are tolerant of wet wastes and are especially useful for many effluents. In addition, they are low-cost, nonflammable materials with the potential to provide chemical and physical immobilization of wastes, but their set characteristics can be affected by certain material additions. Table I balances some advantages against disadvantages of the use of cement systems for waste immobilization.

scholarly journals Corrosion resistance of urtites and urtite-based concretes

2021 ◽  
Vol 34 (02) ◽  
pp. 1008-1020
Author(s):  
Tatyana P. Belogurova ◽  
Yuriy N. Neradovskiy ◽  
Svetlana V. Bastrygina
Keyword(s):  
Corrosion Resistance ◽  
Calcium Hydroxide ◽  
Raw Materials ◽  
Construction Materials ◽  
Environmental Issue ◽  
Cement Matrix ◽  
Acid Media ◽  
Concrete Aggregates ◽  
Technogenic Raw Materials ◽  
Current Standards

The utilization of unconventional technogenic raw materials in producing construction materials is a topical economic and environmental issue. The issue's resolution is impeded by the fact that the overburden rocks of apatite nepheline deposits contain nepheline classified as a deleterious impurity for concrete aggregates under the current standards. This paper is aimed to conduct specialized tests of rocks, aggregates, and concretes for evaluating the corrosion resistance of these materials in water and acid media. The work involved using physical mechanical techniques as well as light and scanning microscopy. It is scientifically validated that nepheline aggregate included in concrete and behaving actively as related to calcium hydroxide produces a denser area of contact with the cement matrix, which favours an enhanced corrosion resistance of concrete. The paper's information is scientifically and practically valuable for resolving the issue with recycling the mining waste of apatite nepheline deposits and utilizing their overburden rocks as concrete aggregates.

PEMANFAATAN LIMBAH KULIT DURIAN (Durio zibethinus) DAN KULIT CEMPEDAK (Artocarpus integer) SEBAGAI EDIBLE FILM

2014 ◽  
Vol 6 (1) ◽  
pp. 27 ◽  
Author(s):  
Desi Mustika Amaliyah
Keyword(s):  
Tensile Strength ◽  
Food Packaging ◽  
Raw Materials ◽  
Edible Films ◽  
Edible Film ◽  
Durio Zibethinus ◽  
Yield Result ◽  
Pre Treatment

Durian (Durio zibethinus) and cempedak (Artocarpus integer) peels waste are not used by the society. The research aim is to extract pectin from durian and cempedak peels and to formulate the pectin into edible films for food packaging. The research stages were first pre-treatment of durian and cempedak peels, pectin extraction, pectin drying, and  pectin application as edible films with concentration of 0%, 5%, and 15%. Based on this research it was concluded that pectin can be extracted from durian and cempedak peels with yield result of 27.97 % and 55.58 %, respectively. Edible film obtained has  similar characteristics between raw materials cempedak and durian peels. The higher concentration of cempedak peel  pectin increased the thickness, but decreased the tensile strength and elongation at a concentration of 15%. While in edible films from durian peel pectin, the higher concentration of pectin decreased the thickness of edible film on pectin concentration of 15%, lowered tensile strength and raised the edible film elongation.Keywords: waste, durian, cempedak, pectin extraction, edible film

FUNDAMENTAL CAPITAL FINANCING OF PRODUCTION

2020 ◽  
Vol 8 (3) ◽  
pp. 74-78
Author(s):  
Farrux Zulfiyev ◽  
Keyword(s):  
Raw Materials ◽  
Economic Reforms ◽  
Equity Financing ◽  
Capital Financing ◽  
The Republic ◽  
The Stability

This article is based on the principles of shared financing of the production of raw materials. The article is aimed at financing the production of capital on the basis of equity in order to further strengthen the stability of economic reforms in the republic. At the same time, the essence of equity financing, the risks associated with it, and the efficiency of raw materials are covered

CREATION OF THE INDUCED APPLE-THREE TETRAPLOIDS

1970 ◽  
pp. 23-25
Author(s):  
L. V. Tashmatova ◽  
О. V. Mantseva ◽  
N. V. Gorbacheva
Keyword(s):  
Environmental Conditions ◽  
Selection Process ◽  
Normal Growth ◽  
Cytological Analysis ◽  
Open Pollination ◽  
Apple Breeding ◽  
Adverse Environmental Conditions ◽  
Diploid Gametes ◽  
Resistance To Diseases

The basic moments of a process of obtaining apple tetraploids as donors of diploid gametes for apple breeding with polyploidy using are demonstrated. In industrial terms, triploids are of the greatest importance. The manifested effect of heterosis leads to the improvement of many characteristics - higher resistance to diseases, pests and adverse environmental conditions, greater autogamy than in diploids, less pronounced periodicity of fruiting, larger fruits and a convenient crown for harvesting. Triploids are developed as a result of crosses 2n × 3n or 2n × 4n. Tetraploids are necessary for more successful apple breeding with polyploidy using. For industry they are not of great importance but they are of interest as donors of diploid non-reduced gametes and allow to make the selection process more directional. One of the methods of experimental polyploidy is the induction of polyploids using mutagenes. The germs were treated with colchicines at concentrations 0.1% - 0.4% during 24 and 48 hours. According to the morphology the obtained plants were divided into five groups. Colchicine concentrations 0.3% and 0.4% during 48 hours of the treatment had a disastrous impact on the development of germs. As a result of the cytological analysis, tetraploids and chimeras were revealed, which were obtained from the seeds from the open pollination of Orlik and Svezhest (treatment variants – 0,1% colchicines solution and 24 and 48 hours of exposition), as well as from the seeds obtained as a result of the Svezhest × Bolotovskoye crossing. Tetraploids had a normal growth but they differed in large leaves, while chimeras were of low size with normal leaves and internodes.

Bamboo Waste-based Bio-composite Substance: An application for Low-cost Construction Materials

2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero
Keyword(s):  
Composite Materials ◽  
Sea Water ◽  
Raw Materials ◽  
Low Cost ◽  
Construction Materials ◽  
Single Layer ◽  
High Strength ◽  
Green Technology ◽  
Experimental Medium ◽  
Natural Treatment

Bamboo is a lightweight and high-strength raw materials that encouraged researchers to investigate and explore, especially in the field of biocomposite and declared as one of the green-technology on the environment as fully accountable as eco-products. This research was to assess the technical feasibility of making single-layer experimental Medium-Density Particleboard panels from the bamboo waste of a three-year-old (Dendrocalamus asper). Waste materials were performed to produce composite materials using epoxy resin (C21H25C105) from a natural treatment by soaking with an average of pH 7.6 level of sea-water. Three different types of MDP produced, i.e., bamboo waste strip MDP (SMDP), bamboo waste chips MDP (CMDP) and bamboo waste mixed strip-chips MDP (MMDP) by following the same process. The experimental panels tested for their physical-mechanical properties according to the procedures defined by ASTM D1037-12. Conclusively, even the present study shows properties of MDP with higher and comparable to other composite materials; further research must be given better attention as potential substitute to be used as hardwood materials, especially in the production, design, and construction usage.

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