AN ANALYTICAL RESEARCH ON FLY ASH POLYMER MATERIAL WITH INNOVATIVE IDEAS: A REVIEW
Ritesh Kumar Raman
Research Scholar, Department of Civil Engineering, Eklavya University, Damoh (M.P.) India
Prof. Hari-Ram Sahu
Asso. Prof., Department of Civil Engineering, Eklavya University, Damoh (M.P.) India
Abstract - Modern waste like fly-debris which is making natural issues, is essentially utilized as a structure material because of its minimal expense and simple accessibility. In any case, the principle impediment of these blocks is its low strength. In this way, a great deal of examination is proceeding to build the strength of these blocks. The current examination work is completed to foster another methodical methodology to deliver fly debris composite blocks which will have higher compressive strength. Here the fly-debris is blended in with Cold setting gum at various extents and water treated at various temperatures to discover an answer for the block business.
1. INTRODUCTION
The whole advancement of a nation relies upon the creation worth of force and thusly its utilization as energy. Our country, India needs enormous power assets to meet the assumption for its tenant just as its intend to be a created country by 2020. Non-renewable energy source has a significant impact in fulfilling the need for influence age .Coal is viewed as one of the world's most extravagant and generally disseminated petroleum product. All throughout the planet, India overwhelms the third situation in the biggest creation of coal and has the fourth biggest coal holds approx. (197 Billion Tons). It has been assessed that 75% of India's absolute introduced power is warm of which the portion of coal is around 90%. Almost around 600 Million tons of coal is created worldwide consistently, with Fly debris age is around 500 MT at (60-78 %) of entire debris delivered [1, 2].In India, the current age of FA is almost around 180 MT/year and is plausible to increment around 320 MT/year by 2017 and 1000MT/year by 2032 [3]. No uncertainty Indian coal has high debris content and low hotness esteem. To satisfy the expanding testing needs, many coal based nuclear energy stations have been developed. Because of which tremendous measure of combusted buildup as Fly debris (80%), and Bottom debris (20%) has been delivered. The finely scattered molecule from the copied coal is released
out through the pipe gases which are withdrawn precisely through electrostatic precipitators and separators which are then gathered together in the field of containers. The pace of creation of FA is high and it continues expanding a seemingly endless amount of many years.
The yearly creation of FA in China, India and US is approximated around 275 million metric tons. In any case, not exactly 50% of this is burned-through in different regions. The best test before the handling and assembling ventures is the removal of the remaining side-effects. The destructive effect on the environmental factors proposes the need for fitting unloading of fly debris and legitimizes full use of FA when doable. Side-effects that are for the most part harmful, ignitable, destructive or responsive have inconvenient climate results. This significant issue requires a successful, monetary and eco-accommodating strategy to handle with the removal of the leftover modern side-effects. The issue with safe removal of debris without influencing the climate, upsetting biological equilibrium and the enormous stockpiling region required are significant issues and difficulties for protected and economical improvement of the country.
Consequently needful endeavors are being made persistently by making severe guidelines by the public authority to completely use the debris. Right now just half of the fly debris is by and large productively used in India [4]. The most
widely recognized and practical ways of using these modern squanders items is to go for development of streets, interstates and dikes. The Problem with natural contamination can be extraordinarily diminished if these squanders items be adequately used in development of streets, roadways and dikes. Yet, adequate measure of soil of wanted quality isn't accessible without any problem. So these modern squanders not just utilized as an other for normal soils in the development rather it additionally tackle the issues of removal and climate contamination. This will give various huge advantages to the developing business just as to the nation overall by protection of normal assets, by decrease of volume of waste to landfills, by bringing down the expense of development materials, and by bringing down garbage removal costs.
With the assistance of some appropriate stabilizer like lime, thermosetting saps or concrete, the properties of fly debris can be expanded and it tends to be additionally utilized as a development material. FA shows self - solidifying conduct that is the reason it is utilized in development extensively.
2. CLASSIFICATION OF FLY ASH Fly ash can be classified into Class F and Class C according to ASTM C618 [15]
based on the amount of lime present.
Based on calcium reactivity, I.S. 3812 [16]. The type of coal burned and the ash content indicate the type of fly ash. Class F fly ash contains very little lime and ash above 70 Wt. % Of Sio2 + Al2o3 + Fe2o3.
On the other hand, the ash content is 5070 Wt. Percentage Sio2 + Al2o3 + Fe2o3 and high lime content are classified as Class C. Class F fly ash can be made from anthracite or bituminous coal, while sub bituminous or lignite makes class C fly ash. Anthracite is not used to generate electricity, so you can easily get Class F fly ash from this coal. The characteristic of Class F fly ash is that it is a low calcium ash with a lime content of 6, so it does not self-cure. However, this class usually exhibits the characteristics of pozzolans. This class of ash contains more than 2% unburned carbon, which can be determined by the (LOI) test. The major crystalline phases in the form of quartz, mullite and hematite identified fly
ash from bituminous coal. Due to some of the important properties of Class fly ash, it is currently the most suitable fly ash for research. The cement compound produced by the hydration of Portland cement is also produced by the reaction of FA produced by bituminous coal with lime or calcium hydroxide in the presence of water. Previous studies have shown that Class F fly ash can replace 1530% of cement with its satisfactory and acceptable aggregate. Class F fly ash can be used to minimize water requirements and heat of hydration. It is also highly resistant to the penetration of sulfate and chloride ions. Class C fly ash, also known as high calcium ash with a lime (Cao) content above 15 °, was not available in the concrete industry until the last 20 years of the 1970s. This ash is essentially pozzolan and self-cemented.
2.1 Fly Ash Properties
Investigating fly ash characterization of structural morphology, phase interfaces, and their susceptibility to chemical changes (reactivity) is critical to finding desirable uses for FA. FA is characterized by its physical, chemical and mineralogy properties. These properties are highly dependent on the nature of the coking coal, combustion conditions, various emission controls, storage and processing methods [17].
2.1.1 Physical Properties
Some physical properties help classify fly ash for a variety of technical purposes. FA is predominantly spherical and consists of solid or hollow fine powder particles.
These particles are predominantly glassy (amorphous) and probably have several crystalline phases. When coal burns [18], oxidation occurs, so fly ash contains very little carbon and nitrogen [19]. The color of fly ash changes from gray to black because the amount of unburned carbon changes little [2]. The carbonaceous material of FA has an angular shape. The difference in particle size between bituminous coal FA and silt is not so big.
Usually less than 0.075 mm. Sub- bituminous coal FA is slightly coarser than bituminous coal FA, but both are subsided. Fly ash has a specific gravity in the range of 1.83.2 and a specific surface area in the range of 180-1000m2/kg [20-
23]. The average diameter of these fly ash particles is less than 10 micrometers and the size is 0.01-1000 micrometers [16].
Spherical morphology, low bulk density, and low bulk density lead to severe limits on fly ash pile height, limiting the height of ash embankments to increase ash pond storage capacity.
2.1.2 Chemical Properties
The properties of fly ash are strongly influenced by various parameters such as the nature of the coal and the handling, storage and processing methods of different types of coal. There are basically four types of coal in nature. These are bituminous coal, subbituminous coal, anthracite coal, and lignite. Each type of coal is chemically different from other coals and is quite different in calorific value, chemical arrangement, amount of ash present, and geographic origin.
Silicon, aluminum and iron oxide are the main components of anthracite. Various amounts of unburned carbon can be measured by LOI, one of the most important chemical properties of FA. The ash produced from lignite is rich in Ca and Mg oxides, usually 1225% compared to bitumen FA, with a reduced proportion of silicon dioxide and iron oxides (Fe2o3, Fe3o4) [24]. You can find what is used in lignite FA. Apart from the handling of ash, i. NS. There are several further categories of wet or dry, one of which is coal-derived ash. Anthracite FA is rarely used because it contains a lot of carbon. Large boilers burn only a certain amount of anthracite, resulting in a low FA concentration. In addition, lignite and subbituminous FA have high concentrations of sulfate ions.
The acidity and alkalinity of FA can be predicted based on the amount of sulfur, calcium and magnesium in the starting carbon. Burning coal produces large amounts of sulfur and FA is characterized as acidic. On the other hand, if the starting coal has a low sulfur content, the FA produced from that coal will be more alkaline. The FA matrix contains hydroxide and carbonate salts on calcium and magnesium substrates and exhibits alkaline behavior from ash residues [25].
As a result, the hydrogen potential (pH) of fly ash particles is between the limits of 4.3 and 12.5 [26]. Due to the presence of soluble salts, the electrical conductivity of
fly ash particles ranges from 0.63 to 55 dsm1 [25].
2.2 Uses of Fly Ash
Fly ash is used in various fields. In general, FA use can be divided into three categories.
Large amounts of FA are used in various areas that are less important for cost reasons. Some of its common uses include the brick industry, backfilling of mines, mountain ridges and the discovery and regeneration of wastelands.
Much effort has been made to make bricks by different manufacturers using lime, different types of resins, plasters and clays. These binders are mixed with FA in various proportions and many products are on the market. FA bricks are more noticeable because they save valuable top layer soil. Similarly, when river sand used to load mines into underground mines is depleted, ash will be widely used to backfill mine pits. Studying the leaching effect using FA is essential prior to application.
FA is widely used as a cement stabilizer, post-tension construction, lightweight filler material for wall slate and roof tiles, insulation blocks, paints and enamel, and herbicides that destroy unwanted plants in agriculture. All of these fall into the medium cost category.
Extraction of various magnetic oxides, aluminum oxide (Al2O3), and various trace elements, synthesis of zeolites for industrial applications, and production of inorganic wool. Removal of bleach and organic compounds from waste water, mercury from flue gas, and adsorbents (Sox and Nox emissions) to clean flue gas. These are grouped under high cost values.
2.3 FA Disposal –Curse to Environment Thermal power plants generate large amounts of solid waste in the form of fly ash. This waste is widely used in various building materials and other fields. In addition to meeting demand, the disposal of FA is a burning problem, hindering the
development of a green nation. Therefore, it is a big concern. Here are some of the issues with FA disposal: [27]
• Fly ash particles are available in both dry and wet conditions. This ash is disposed of in large quantities, occupies thousands of acres of land and destroys topsoil fertility.
• Treating FA particles during drying can be a daunting task. This is because these ashes are very finely dispersed. Fine particles of FA destroy the structural shell and interfere with culture.
• It disrupts ecosystems by various types of pollution. NS. Soil, air, water.
• Since FA is discarded in the atmosphere, it is exposed to the air for a long time, which ultimately leads to various airborne infections.
• Disposing of FA in the surrounding area before treatment also affects the biological properties of the soil and the overall yield of the plant.
2.4 Reviews on FA
Many researchers have worked on the properties of coal ash and evaluated its importance in various fields. Some of them are shown below.
Sherwood and Ryley stated that fly ash is self-curing due to the presence of free lime in the form of calcium oxide or calcium hydroxide.
McLaren and Desioiab have shown that fly ash has a relatively low density than soil. Currently, these patties can be used on spongy walls and ridges, especially if the foundation is weak.
Sridhara netal. Examine the microscopic image of FA particles with SEM. These particles are solid spheres, mostly glassy in appearance, hollow spheres with smooth, porous particles, asymmetric aggregates, and irregular absorption residues of unburned carbon. The presence of dark gray iron particles can be identified as sharp particles.
According to Mohini Saxena and P.
Asokan, many interdisciplinary tests have been conducted on coal ash at various experimental centers. The
Bhopal Regional Institute has done a lot of work on FA and improved various methods of pilot-scale demonstrations. They cultivated crops, vegetables and grains and reported that the use of non-toxic FAs resulted in higher yields than before. They have also developed paints with FA and epoxy systems for safety and beautification. These FA paints have improved resistance to rust, wear and wear.
Mitchell and Brown show that soil, FA, and lime behave uniquely and are much more dependent on fly ash and soil physicochemical properties such as porosity, segregation, lime content, time and pressure during compression. I said.
Sevelius et al. He studied the use of fly ash and slag in brickmaking and refractory. We also investigated that the consumption of FA as a basic raw material has increased significantly.
Mathur et al. focused on the effects of heavy metals in FA on various plant species such as Ipomeas carnea, Typha angustata and Calotropis procera.
Martin et al. FA has found that due to the tensile stress generated by the capillarity of water, it exhibits aggregation properties when wet but unsaturated. This property limits the long-term strength of the part.
He concluded that the shear angle is more important for improving mechanical strength.
Indraratna et al. showed a comparison of aggregated cross- sections and shear angles of dried and wet fly ash samples. He reported that there was no change in drag shear angle and 100% loss of cohesion, mainly in dry samples.
2.5 Reviews on Fly Ash Bricks
Fly ash-based bricks offer exciting advantages over traditional mudbricks.
Intensive research is being conducted around the world to improve the functional properties of fly ash-based geopolymers. This chapter outlines some of the latest reports published in the fly
ash-based geopolymer literature, their use in brick manufacturing, and their mechanical properties. Fly ash bricks have received a great deal of attention from material experts and engineers in recent years, considering the development of eco-friendly, high-strength materials and the partial conversion of clay bricks currently in use.
Obada Kayali studied the properties of fly ash and clay bricks and concluded that the mechanical properties of fly ash bricks exceed those of standard load-bearing clay bricks. The compressive strength was 24 superior to that of good quality clay bricks, and the tensile strength was almost three times that of standard clay bricks. The adhesive strength of fly ash bricks is 44% higher than that of regular clay bricks. The density of fly ash bricks is 28% lower than that of standard clay bricks. The lighter weight of bricks saves a lot of raw materials and transportation costs. Fly ash bricks easily absorb mercury from the normal air that comes in contact with them, making them cleaner against abuse. There is also a process called carbonization that helps fly ash absorb carbon dioxide from the normal atmosphere, thereby binding carbon and reducing the amount of carbon in the atmosphere to minimize global warming.
Sunil Kumar provided a detailed review of the reported work on fly ash bricks. He investigated the bending strength, water absorption test, density, porosity, and stability of these solid and hollow blocks. He witnessed that these bricks and blocks were strong enough to be used in low-growth areas of housing.
The test was conducted to determine the compressive strength and curing effect and to analyze the effect of curing over time. Molds treated with hot water show better strength and curing effect than regular water-cured moldings. The strength of these blocks and bricks first increases at a high rate and then at a relatively slow rate. There is a direct relationship between FA and fluid intake.
As the FA content increases, so does the water absorption rate. On the other hand, as the density of FA pellets increases, the water absorption rate decreases. These FA bricks and blocks with the correct phosphorus gypsum content have
improved resistance to a robust sulfur environment.
Ball MC & Carroll RA studies various brick manufacturing processes and understands the reasons for the reinforcing effect of these autoclaved FA bricks. FA bricks are hardened mainly by the formation of calcium silicate hydrate and calcium aluminate silicate hydrate.
When the pellets are cured in a steam bath, typically 1100°C 1800°C, a hydrothermal reaction occurs between silica, aluminum oxide and water. The To- Bermorite phase also helps improve the hardenability of fly ash bricks.
Cultrone G, Sebastian E, and Elert K investigated the permeability of FA bricks and correlated their effects on the various chemical and mineralogy constituents of fly ash particles. FA stones also depend on the firing temperature, resulting in a more vitrified and dense structure and tremendous changes in shape and size.
Dimitrios Panias and Ioanna P.
Said that water content has proven to be an important parameter in the synthesis of FA geopolymers in order to develop better mechanical strength. Water increases its importance at various cure points in suspensions, polycondensations, and geopolymerizations. The presence of NaOH strongly affects the compressive strength during the formation of the geopolymer. Geopolymers synthesized with higher or lower NaOH content (aqueous phase) lead to reduced compressive strength. The concentration of the sodium silicate (Na2SiO3) solution during the formation of the geopolymer had a significant effect on the compressive strength achieved. The Na2SiO3 solution improves the strength of the molding material by controlling the collection of soluble silicates and the most important silicate class in the geopolymer system.
3. CONCLUSIONS
Based on this study, the following conclusions can be drawn.
1) Water treated pellets have a positive effect on hardness values. Of all dry compacts, 85% by weight FA has a higher hardness value of 44.08HV.
Treatment of the composite in water at 1100 - 1800°C significantly
improved the hardness value, which increased to 47.37 HV. This increase in hardness value is due to the presence of CSH and CASH in the presence of moisture obtained from XRD analysis.
2) As the amount of polymer (resin powder) added increases, the compressive strength of the dried pellets decreases to a low value of 6.5 MPa. The composition of 75wt shows a lower value. Wet compact does not show a significant decrease in compressive strength.
3) Abrasion tests on various composites can be easily correlated with hardness values. FA is 85wt in both dry and wet conditions.
Composition shows better wear resistance than the other two compositions. Abrasion resistance increases with increasing FA content. The coefficient of friction decreases with increasing FA percentage and follows a linear trend throughout the test period.
4) The thermal conductivity of FA increases with increasing temperature, but in the case of resin powder/FA mixture, the thermal conductivity of the composite decreases with increasing temperature. It has a much lower conductivity value and can be used in place of clay.
REFERENCES
1. Joshi RC, Lothia RP. Fly ash in concrete:
production, properties and uses. In: Advances in concrete technology, vol. 2. Gordon and Breach Science Publishers; 1999.
2. Ahmaruzzaman M. A review on the utilization of fly ash. Prog Energy Combust 2010;
36:327–63.
3. Rai A.K., Paul B. and Singh G., A study on physico chemical properties of overburden dump materials from selected coal mining areas of Jharia coalfields, Jharkhand, India, Int. Journal of Environmental Sc., 1 (2011):
pp. 1350-1360.
4. Sahay A. N., R & D initiatives in utilization of fly ash in coal sector, in: Proc. of Fly ash an opportunity for Mining Sector, New Delhi, India, 2010, pp. 26-35.
5. Das S.K. and Yudhbir, Geotechnical properties of low calcium and high calcium fly ash, Journal of Geotechnical and Geological Engineering, 24 (2006): pp. 249-263.
6. Sinsiri T, Chindaprasirt P, Jaturapitakkul Ch.
Influence of fly ash fineness and shape on the porosity and permeability of blended cement
pastes. Int J Miner Metal Mat 2010; 17:683- 690.
7. P.S.M. Tripathy, S.N. Mukherjee, Perspectives on Bulk Use of Fly Ash, CFRI Golden Jubilee Monograph, Allied Publishers Limited, 1997, p. 123.
8. Sidhu, Buta Singh, Singh, Harpreet, Puri D., Prakash, S., “Wear and Oxidation Behavior of Shrouded Plasma Sprayed Fly ash Coatings”, Tribology International, Volume 40, (2007), pp.800-808.
9. China Economic Trade Committee, Tenth five-year program of building materials industry, China Building Materials 7, 2001, pp. 7–10.
10. P. Wouter, Energy Performance of Building:
Assessment of Innovative Technologies, ENPER-TEBUC, Final Report, 2004.
11. M. Anderson, G. Jackson, The history of pulverized fuel ash in brick making in Britain, J. Inst. Ceram. 86 (4) (1987) 99–135.
12. M. Anderson, G. Jackson, The beneficiation of power station coal ash and its use in heavy clay ceramics, Trans. J. Br. Ceram. Soc. 82 (2) (1983) 50–55.
13. Pofale and Deo, 2010; Kumar, 2000; Reddy and Gourav, 2011; Dry et el., 2004; Mitraet al., 2010).
14. Shenbaga, R. Kaniraj and V. Gayathri (2004),
“Permeability and Consolidation Characteristics of Compacted Fly Ash”, Journal of Energy Engineering. ASCE, Vol.
130, 117-211.
15. ASTM C 618-08a (2008) Standard specification for coal fly ash and raw or calcined natural pozzolan for use in concrete, American Society for Testing and Materials.
16. ASTM C 618-08a (2008) Standard specification for coal fly ash and raw or calcined natural pozzolan for use in concrete, American Society for Testing and Materials.
17. Jala S, Goyal D. Fly ash as a soil ameliorant for improving crop production – a review.
Bioresour Technol 2006; 97(9):1136–47.
18. Sikka R, Kansal BD. Characterization of thermal power-plant fly ash for agronomic purposes and identify pollution hazards.
Bioresour Technol 1994; 50:269–73.
19. Matsi T, Keramidas VZ. Fly ash application on two acid soils and its effect on soil salinity, pH, B, P and on ryegrass growth and composition. Environ Pollut 1999;
104(1):107–12.
http://flyashindia.com/properties.htm.
20. Roy WR, Thierry RG, Schuller RM, Suloway JJ. Coal fly ash: a review of the literature and proposed classification system with emphasis on environmental impacts. Environmental geology notes 96. Champaign, IL: Illinois tate Geological Survey; 1981.
21. Tolle DA, Arthur MF, Pomeroy SE. Fly ash use for agriculture and land reclamation: a critical literature review and identification of additional research needs. RP-1224-5.
Columbus. Ohio: Battelle Columbus Laboratories; 1982.
22. Mattigod SV, Dhanpat R, Eary LE, Ainsworth CC. Geochemical factors controlling the mobilization of inorganic constituents from fossil fuel combustion residues: I. Review of
the major elements. Journal of Environmental Quality 1990;19:188–201.
23. Da Costa JCD, Prasad P, Pagan RJ. Modern environmental improvement pathways for the coal power generation industry in Australia.
Process Safe Environ Protect 2004;
82(3B):191–9.
24. Matsi T, Keramidas VZ. Fly ash application on two acid soils and its effect on soil salinity, pH, B, P and on ryegrass growth and composition. Environ Pollut 1999;
104(1):107–12.
25. Pandey VC, Singh N. Impact of fly ash incorporation in soil systems. Agric, Ecosys Environ 2010; 136(1 2):16 27.
26. Pujari GK, Dash PM. Fly ash – problem and management aspect. Envis Newsl Centre Environ Stud 2006; 3(1):1–8.
27. ASTM Standard D5334-08 – Standard Test Method for Determination of Thermal Conductivity of Soil and Soft Rock by Thermal Needle Probe Procedure, doi:
10.1520/D5334-08.
28. Chapman TR, Niesz DE, Foxrt, Fawcett T.
Wear 1999; 236:81.
29. Swanepoel J.C., Strydom C.A.: Utilization of fly ash in a geopolymeric material, Applied Geochemistry, vol. 17, pp. 1143-1148, (2002).
30. Fernandez-Jimenez A., Palomo A, Composition and microstructure of alkali activated fly ash binder: Effect of the activator. Cement and Concrete Research, vol. 35, pp. 1984-1992, (2005).
31. Khatri C, Rani A. Synthesis of a nano- crystalline solid acid catalyst from fly ash and its catalytic performance. Fuel. 2008;
87(13):2886–92.
doi:10.1016/j.fuel.2008.04.011.
32. Saikia BJ, Parthasarthy G, Sarmah NC, Baruah GD. Fourier-transform infrared spectroscopic characterization of naturally occurring glassy fulgurites. Bull Mater Sci.
2008; 31(2):155–58.
33. Yuchi Chen, Xian Zhou, Sha Wan, Rui Zheng, Jun Tong, Haobo Hou, Teng Wang, “Synthesis and Characterization of Geopolymer Composites Based on Gasification Coal Fly ash and Steel Slag”, Elsevier, 2019.
34. Gábor Mucsi, Roland Szabó, Ádám Rácz, Ferenc Kristály, Sanjay Kumar, “Combined Utilization of Red Mud and Mechanically Activated Fly Ash in Geopolymers”, The Mining-Geology-Petroleum Engineering Bulletin, 2019.
35. Eslam Gomaa, Simon Sargon, Cedric Kashosi, Ahmed Gheni, and Mohamed A. ElGawad, “Mechanical Properties of High Early Strength Class C Fly Ash- Based Alkali Activated Concrete”, Transportation Research Record, 2020, Vol. 2674(5) 430–443.
36. Wen-Ten Kuo, Ming-Yao Liu and Chuen-Ul Juang,
“Bonding Behavior of Repair Material Using Fly- Ash/Ground Granulated Blast Furnace Slag-Based Geopolymer”, Materials, May 2019.
37. Dumitru Doru Burduhos Nergis, Mohd Mustafa Al Bakri Abdullah, Andrei Victor Sandu and Petrica Vizureanu, “XRD and TG-DTA Study of New Alkali Activated Materials Based on Fly Ash with Sand and Glass Powder”, Materials, January 2020.
38. Rosicky Methode Kalombe, Victor Tunde Ojumu, Chuks Paul Eze, Sammy Mwasaha Nyale, John Kevern and Leslie Felicia Petrik, “Fly Ash-Based Geopolymer Building Materials for Green and Sustainable Development”, Materials, December 2020.
39. Jeesoo Sim, Youngjeong Kang, Byung Joo Kim, Yong Ho Park, and Young Cheol Lee, “Preparation of Fly Ash/Epoxy Composites and Its Eects on Mechanical Properties”, Polymers, 2020.
40. Chinchu Cherian and Sumi Siddiqua, “Pulp and Paper Mill Fly Ash: A Review”, Sustainability, August 2019.
41. S. K. Nath, “Fly Ash and Zinc Slag Blended Geopolymer: Immobilization of Hazardous Materials and Development of Paving Blocks”, Journal of Hazardous Materials, July 2019.
42. Uyiosa Osagie Aigbe, Kingsley Eghonghon Ukhurebor, Robert Birundu Onyancha, Otolorin Adelaja Osibote, Handoko Darmokoesoemo, Heri Septya Kusuma, “Fly ash-based adsorbent for adsorption of heavy metals and dyes from aqueous solution: a review”, journal of materials research and technology 2021; 14: 2751-2774.
43. Grzegorz Ludwik Golewski and Damian Marek Gil,
“Studies of Fracture Toughness in Concretes Containing Fly Ash and Silica Fume in the First 28 Days of Curing”, Materials 2021, 14, 319.
https://doi.org/10.3390/ma14020319.
44. Chan-Yi Lin and Tai-An Chen, “Effects of Composition Type and Activator on Fly Ash-Based Alkali Activated Materials”, Polymers 2022, 14, 63.
https://doi.org/10.3390/polym14010063.
45. Mohammad Mehdi Roshani, Seyed Hamidreza Kargar, Visar Farhangi and Moses Karakouzian, “Predicting the Effect of Fly Ash on Concrete’s Mechanical Properties by ANN”, Sustainability 2021, 13, 1469.
https://doi.org/10.3390/su13031469.
46. Kostas A. Komnitsas and Georgios Bartzas, “Editorial for Special Issue: Alkali Activated Materials: Advances, Innovations, Future Trends”, Minerals 2021, 11, 75.
https://doi.org/10.3390/min11010075.
