scholarly journals Production and Evaluation of Synthetic Lightweight Aggregates Based on Mixture of Fluidized Bed Fly Ash and Post-Mining Residues

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 660
Author(s):  
Grzegorz Skotniczny ◽  
Mateusz Kozioł ◽  
Jerzy Korol ◽  
Paweł Poneta

This paper presents an attempt to obtain technically valuable lightweight aggregate produced from a mixture of fluidized bed fly ash and post-mining residues. The motivation to take up this study is a problem with the reasonable utilization of huge amounts of ashes produced by power plants in Poland. The ashes still produced and those stored in heaps amount to a tonnage of millions, and new ways to utilize them are desired. A real lack of mineral aggregates (non-renewable resources) demands the search for alternative materials. Using the industrial ashes as aggregates is a possible solution to the two above-mentioned problems. The aim of the study was to produce the lightweight aggregate components and to assess them in terms of their physical and mechanical properties. The components were prepared by mixing, granulation, and sintering at the temperature of over 1170 °C. Evaluation of physical parameters was based on parameters such as bulk density and water absorption. The study of mechanical properties was carried out on the basis of aggregates’ resistance to crushing. The obtained results revealed that using a mixture of the combustion and post-mining residues in the production of a lightweight aggregate is beneficial and results in the formation of a porous and durable structure. The measured resistance to the crushing of the produced aggregates varied from 5.9 MPa to 7.5 MPa. They also showed a high freeze-thaw resistance and good resistance to aggressive environments (bases, acids, salt). The registered properties indicate that the aggregates meet the basic requirements for materials used in construction and road-building. This study has a scientific and didactic value in that it describes the step-by-step process of planning and implementing the production of synthetic mineral aggregates.

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3018 ◽  
Author(s):  
Mirjana Vukićević ◽  
Miloš Marjanović ◽  
Veljko Pujević ◽  
Sanja Jocković

Major infrastructure projects require significant amount of natural materials, often followed by the soft soil stabilization using hydraulic binders. This paper presents the results of a laboratory study of alternative waste materials (fly ash and slag) that can be used for earthworks. Results of high plasticity clay stabilization using fly ash from Serbian power plants are presented in the first part. In the second part of the paper, engineering properties of ash and ash-slag mixtures are discussed with the emphasis on the application in road subgrade and embankment construction. Physical and mechanical properties were determined via following laboratory tests: Specific gravity, grain size distribution, the moisture–density relationship (Proctor compaction test), unconfined compressive strength (UCS), oedometer and swell tests, direct shear and the California bearing ratio (CBR). The results indicate the positive effects of the clay stabilization using fly ash, in terms of increasing strength and stiffness and reducing expansivity. Fly ashes and ash-slag mixtures have also comparable mechanical properties with sands, which in combination with multiple other benefits (lower energy consumption and CO2 emission, saving of natural materials and smaller waste landfill areas), make them suitable fill materials for embankments, especially considering the necessity for sustainable development.


2013 ◽  
Vol 688 ◽  
pp. 146-151 ◽  
Author(s):  
Pavel Sokol ◽  
Rostislav Drochytka ◽  
Vit Cerný ◽  
Ester Helanová

During rehabilitation work are often strict requirements on the use of high quality lightweight materials, including aggregate. Due the constantly increasing social pressure on the optimal use of secondary raw materials is therefore most appropriate to exploit the potential of fly ash as mineral residue from the combustion of ground coal in power plants. Especially filter fly ash has proven to be an adequate substitute for traditional materials in the past. This article deals with the evaluation of physical and mechanical properties of cold-consolidated pellets based on conventional and fluidized fly ash with various cement addition.


2019 ◽  
Vol 11 (0) ◽  
pp. 1-5
Author(s):  
Deividas Augutis ◽  
Džigita Nagrockienė

Materials used for the study: Portland cement CEM I 42,5 R, 0/4 fraction sand, 4/16 fraction gravel, biofuel fly ash, superplastizer ViscoCrete D187 (V) and water. Seven compositions of concrete were designed by replacing 0%, 5%, 10%, 15%, 20%, 25% and 30% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. Studies have shown that the increase of biofuel fly ash content up to 15% increases concrete density and compressive strengh after 28 days of curing, compressive strength, ultrasonic pulse velocity, closed porosity, concrete forecasted freeze-thaw cycles and decreases water absorbtion, open porosity.


2012 ◽  
Vol 10 (1) ◽  
pp. 005-014 ◽  
Author(s):  
Małgorzata Franus

This paper presents the assessment of the physical and mechanical properties lightweight of aggregate obtained from the addition of expanded clay mineral clay – glauconite and clay from the bed, “Buda Mszczonowska”. Crushed plastic was prepared by firing at a temperature of over 1170 ° C. Evaluation of physical parameters was based on parameters such as density, bulk density and bulk density, tightness, porosity, water absorption. The study of mechanical properties was carried out on the basis of aggregate hardiness, resistance to crushing, abrasion in the drum Los Angeles. In addition, the compounds were determined in the aggregate coloring. Use glauconite in the lightweight of aggregate is beneficial for the texture of the sinter resulting in the formation of a glassy layer on the surface of the granules, and by increasing their porosity. Investigated the properties indicate that the resulting lightweight of aggregate with glauconite meets the basic requirements for materials used in construction.


2021 ◽  
Vol 887 ◽  
pp. 528-535
Author(s):  
V.A. Kalneus ◽  
D.A. Nemushchenko ◽  
V.V. Larichkin ◽  
A.A. Briutov

The article analyses the influence of SiO2 and Al2O3 nanopowders on properties of ceramics consisting of fly ash from thermal power plants, glass waste, and clay binder. Based on studies of physical and mechanical properties of the obtained ceramics (ultimate compressive strength, ultimate three-point bending strength, wear resistance, and water absorption), the paper shows the positive influence of the nanoadditives. The optimal number of SiO2 and Al2O3 nanopowders in the formulation is 0.5 wt. % that has the strongest effect on ultimate compressive strength and water absorption of the fly ash ceramics samples. The direction of further research on improving the properties of ceramic products is an application of the Al2O3 nanopowder as more perspective nanoadditive using clay dispersant.


2014 ◽  
Vol 665 ◽  
pp. 203-207
Author(s):  
Xi Liu ◽  
Bei Bei Lv ◽  
Tao Wu

By choosing domestic ceramsite as lightweight aggregate, mixing with active mineral admixture (fly ash) and the water reducing agent, and adopting the method of absolute volume to design the three ceramsite concretemixture ratio, 27 groups, 243 lightweight aggregate ceramsite concrete test cubes of 100mm×100mm×100mm are obtained for compressive strength test, and the physical and mechanical properties of the aggregate are studied. At the same time, through the systematic test, the influences of the aggregate strength, water-binder ratio, fly-ash content, etc on ceramsite concrete are studied. Finally the best mixture ratio scheme for ceramsite concrete is gained, providing theoretical basis for the application of lightweight aggregate concrete.


Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 779
Author(s):  
Mohamed Gomah ◽  
Guichen Li ◽  
Salah Bader ◽  
Mohamed Elkarmoty ◽  
Mohamed Ismael

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.


2017 ◽  
Vol 866 ◽  
pp. 199-203
Author(s):  
Chidchanok Chainej ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong

The aims of this research were study the microstructures and mechanical properties for partial replacement of cement with Fly ash (FA) and kaolin waste (KW). Ordinary Portland cement were partially replaced with FA and KW in the range of 25-35% and 10-25% by weight of cement powder. The kaolin waste was ground for 180 minutes before using. The specimen was packing into an iron mold which sample size of 5×5×5 cm3. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the incubation lime water bath at age of 3 days. After that the specimens were dry cured with plastic wrap at age of 3, 7, 14 and 28 days. After that the compounds were examined by x-ray diffraction patterns (XRD) and the microstructures were examined by scanning electron microscopy (SEM). The compressive strength was then investigated.


2020 ◽  
Author(s):  
N. H. Teng ◽  
H. C. Yong ◽  
M. M. A. Abdullah ◽  
N. Yong-Sing ◽  
K. Hussin

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