scholarly journals Influence of the Composition and Curing Time on Mechanical Properties of Fluidized Bed Combustion Fly Ash-Based Geopolymer

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2527
Author(s):  
Natalia Wielgus ◽  
Jan Kubica ◽  
Marcin Górski
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Fluidized Bed ◽  
Environmentally Friendly ◽  
Raw Material ◽  
Fluidized Bed Combustion ◽  
Precast Elements ◽  
Ash Disposal ◽  
Fbc Fly Ash

This paper presents novel research on a fluidized bed combustion (FBC) fly ash-based geopolymer as a contribution to the problem of FBC fly ash disposal, and a proposal for a new geopolymer composition—an environmentally friendly material that is possible to use in construction. Geopolymer samples of various composition (containing FBC fly ash as the main raw material, metakaolin and CRT glass as additional components, and sodium silicate and sodium hydroxide as activators) were subjected to flexural and compressive strength tests. An investigation on the effect of the demolding time was carried out on one selected mixture. The test showed that both the composition and the demolding time have a decisive influence on the basic mechanical properties. A mixture containing FBC fly ash to metakaolin in a mass ratio of 3:1, removed from the mold after 14 days, was found to be the best in terms of the mechanical parameters expected from a material that could be used in construction, e.g., for the production of precast elements. According to the results obtained, FBC fly ash is a promising and environmentally friendly raw material for the production of geopolymer, with good mechanical properties and low density. Moreover, a high compressive strength can be obtained by curing the geopolymer at ambient temperature.

scholarly journals Development of the Strength of the Fluidized Bed Combustion Fly Ash Based Geopolymer in Time

2020 ◽  
Author(s):  
Natalia Paszek ◽  
Marcin Górski
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Fluidized Bed ◽  
Curing Temperature ◽  
Hard Coal ◽  
Curing Process ◽  
Fluidized Bed Combustion ◽  
Curing Conditions ◽  
Fbc Fly Ash ◽  
Over Time

ThispaperpresentsastudyintothemechanicalbehaviourofFluidizedBedCombustion (FBC)fly ash-based geopolymer.FBCflyashisaby-product of a burning of a solid fuel (hard coal in case of this study) in a furnace at a low temperature. FBC fly ash is a type of a waste which is more difficult to recycle than pulverized fly ash.UsingFBCflyashin geopolymers offers one possible way to recycle it. The main goals of the investigation were to determine the influence of curing temperature and curing conditions on the strength of FBC fly ash-based geopolymer; to determine the changes of strength over time and the changes of the temperature inside the geopolymer during the curing process. Tests have shown that the strength of the geopolymer generally increases in line with the increase of a curing temperature. The compressive strength stabilizes after 5 days of curing and yet continues to gain extra strength over the longer term. Theflexuralbehaviourisnotmonotonicandthereforehardtopredict.The temperature inside the geopolymer rises rapidly until reaching around 27.5°C and then decreases steadily. Keywords: geopolymer, Fluidized Bed Combustion Fly ash, temperature, strength

scholarly journals Solidification of Municipal Solid Waste Incineration Fly Ash through Co-Mechanical Treatment with Circulation Fluidized Bed Combustion Fly Ash

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 141
Author(s):  
Zhengzhen Yao ◽  
Zhonghui Xu ◽  
Qin Shuai ◽  
Xiaoyue Chen ◽  
Zao Jiang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Fluidized Bed ◽  
Mechanical Treatment ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Fluidized Bed Combustion ◽  
Waste Incineration Fly Ash

This study aims to explore the solidification performance of municipal solid waste incineration fly ash (MSWIFA) through co-mechanical treatment with circulation fluidized bed combustion fly ash (CFBCFA). The mineral characterization, physical properties, and leaching resistance of the solidified bodies are investigated by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry-differential thermal analysis (TG-DTA), compressive strength, porosity, and leaching test, respectively. C–S–H, ettringite (AFt), and Friedel’s salt (FS) are the predominant hydrate products in the CFBCFA based solidified bodies, which are similar to the cement based solidified bodies. However, CFBCFA based solidified bodies exhibit higher compressive strength (36.7 MPa) than cement based solidified bodies (11.28 MPa), attributing to the three reasons: lower porosity and more compact internal structure of CFBCFA based solidified bodies; large amounts of Ca(OH)2 originating from MSWIFA are conducive to promoting the hydration reaction extent and compressive strength of the CFBCFA based solidified bodies; excessive Ca(OH)2 would cause compressive strength deterioration for the cement based solidified bodies. The heavy metals (Zn, Cu, Cr, Cd, and Pb) concentrations in the extraction solution of the CFBCFA based solidified bodies are far below the requirements of Chinese National Standard GB 5085.3-2007. The solidification of MSWIFA through co-mechanical treatment could be an ideal substitute for cement solidification technology.

The Capillary Action of Water in the Binder Gels

2014 ◽  
Vol 1054 ◽  
pp. 148-153
Author(s):  
Tereza Otcovská ◽  
Pavel Padevět
Keyword(s):  
Fly Ash ◽  
Fluidized Bed ◽  
Cement Paste ◽  
Coal Combustion ◽  
Waste Product ◽  
Fluidized Bed Combustion ◽  
Capillary Action ◽  
Fbc Fly Ash ◽  
Pulverised Coal

Fly ash is a waste product produced during combustion of coal. There are two basic types of fly ash. According to the type of combustion, there is produces pulverised coal combustion (PCC) fly ash or fluidized bed combustion (FBC) fly ash. Use of fly ash additives influences moisture properties of binder gels (cement paste). The particular object of interest of this post is capillary action of water in the binder gels with different concentration of fly ash in the mixture. There are substantial differences among moisture properties of binder gels with FBC fly ash additives compared with the binder gels with PCC fly ash additives.

Optimization of Alternative Aggregates Based on Fluid Combustion Fly Ashes

2016 ◽  
Vol 851 ◽  
pp. 75-79 ◽  
Author(s):  
Jiří Kratochvíl ◽  
Hana Kalousová ◽  
Tomáš Opravil
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Fluidized Bed ◽  
Fluidized Bed Combustion ◽  
Fly Ashes ◽  
Secondary Resources

Effective usage of fluidized bed combustion fly ash is very low. These valuable resources are mostly deposited or in the best case used as a filler in excavated areas. Only very small amount is used differently. This paper presents one of the possibilities of usage of these interesting secondary resources. The goal of this paper is to investigate possibilities of preparation of alternative aggregate based on fluid combustion fly ashes. The work is focused on the study of mechanical properties of prepared aggregates. Monitoring of other properties including impact of the quality of fly ash in time, which has been stabilized as far as possible in recent years, will be addressed in the following work.

scholarly journals Permeability of the Mixture of Fine Grained Soil and Fly Ash from Fluidized Bed Combustion

2017 ◽  
Vol 17 (2) ◽  
pp. 25-30
Author(s):  
Karolina Knapik ◽  
Joanna Bzówka
Keyword(s):  
Fly Ash ◽  
Water Content ◽  
Fluidized Bed ◽  
Initial Water Content ◽  
Curing Time ◽  
Fluidized Bed Combustion ◽  
Initial Water ◽  
Fine Grained ◽  
Fine Grained Soil ◽  
Fbc Fly Ash

Abstract Based on known correlations permeability was calculated for the mixtures containing various proportions of selected FBC fly ash, Speswhite kaolin and lime. The influence of initial water content of the mixtures was also considered. The study was limited to the first four weeks of curing time. Results of calculations were discussed on the background of previously obtained observations for mixtures of tested materials.

scholarly journals Circulation Fluidized Bed Combustion Fly Ash as Partial Replacement of Fine Aggregates in Roller Compacted Concrete

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4204 ◽  
Author(s):  
Wei-Ting Lin ◽  
Kae-Long Lin ◽  
Kailun Chen ◽  
Kinga Korniejenko ◽  
Marek Hebda ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Fluidized Bed ◽  
Setting Time ◽  
Unit Weight ◽  
Fluidized Bed Combustion ◽  
Sulfate Resistance ◽  
Roller Compacted Concrete ◽  
Fine Aggregates

Recently, many people around the world have been concerned with environmental protection and sustainability. The goal of various countries’ research has been focused on how to regenerate existing resources. Circulation fluidized bed combustion (CFBC) technology is one of the emerging combustion technologies for electricity generation and produces more than 800,000 tons of CFBC fly ash (CFA) per year for combustion. CFA has been widely applied in cement additive, new building materials and cement-based materials. The goal of this study was to discuss the engineering properties of roller-compacted concrete containing CFA. Test subjects included compressive strength, flexural strength, absorption, setting time, unit weight, sulfate resistance, SEM microscopic observations and XRD ingredient analysis. Test results indicate the following: (1) using CFA as a substitute of fine aggregates up to 10 wt.% would improve the development of later flexural strength; (2) the increases in pre-pressure would increase the compressive strength and unit weight and decrease absorption; (3) using CFA would reduce the initial setting time by 30%–60% and reduce the final setting time by 16%–20%; (4) using CFA would reduce the absorption; (5) using CFA would reduce the unit weight by 0.5%–2.8%, and the increases in pre-pressure would increase the unit weight by about 0.9%–2.1%; (6) CaO in CFA helps to improve sulfate resistance; (7) scanning electron microscopy (SEM) observation shows that the increases in pre-pressure would reduce the pores; and (8) X-ray diffraction (XRD) analysis shows that the inclusion of CFA would increase the content of Ca(OH)2 in concrete.

scholarly journals Mechanical Activation of the Ca-Rich Circulating Fluidized Bed Combustion Fly Ash: Development of an Alternative Binder System

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 3
Author(s):  
Peeter Paaver ◽  
Päärn Paiste ◽  
Martin Liira ◽  
Kalle Kirsimäe
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Activation ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Chemical Activation ◽  
Fluidized Bed Combustion ◽  
Strength Performance ◽  
Mineral Characteristics ◽  
Circulating Fluidized Bed Combustion

Mechanical activation of the calcium-rich fly ash formed in circulating fluidized bed combustion (CFBC) boilers was investigated to enhance the compressive strength performance of the pastes. We studied the effect of the activation on the physical, chemical, and mineral characteristics of fly ash and its pastes. Our study shows that already a short mechanical activation yields a 10-fold improvement in the compressive strength of the pastes, reaching 60 MPa after 90 days of curing without any chemical activation or blending. Mechanical activation caused fragmentation of large porous aggregates in the raw ash enhancing the physical properties and reactivity of fly ash particles. Similarly to calcium sulfoaluminate cements, the mechanical strength was provided by the formation of abundant ettringite and possibly C-(A)-S-H gel-like phase that created a highly compact microstructure. Our findings suggest that mechanically activated Ca-rich CFBC fly ash can be successfully used as an alternative binder.

scholarly journals Mechanical Properties of Basalt Fiber Reinforced Fly Ash-Based Geopolymer Composites

2020 ◽  
Author(s):  
Kinga Korniejenko ◽  
Gábor Mucsi ◽  
Nóra Papné Halyag ◽  
Roland Szabó ◽  
Dariusz Mierzwiński ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Microstructural Analysis ◽  
Basalt Fiber ◽  
Raw Material ◽  
Basalt Fibre ◽  
Control Series ◽  
Fibre Composites ◽  
Geopolymer Composites

This article analyses the influence of a short basalt fibre admixture on the mechanical properties of geopolymers, especially compressive strength. This preliminary research is the first step towards the development of a composite for fire resistant applications in civil engineering. This study investigates the behaviour of a fly ash based geopolymer containing basalt fibres. Fly ash from the coal power plant ‘Skawina’ (located in: Skawina, Lesser Poland, Poland) was used as the raw material. The chemical composition of this fly ash is typical for class F. Three series of fly ash based geopolymers were cast. In the first, short basalt fibres were added as 1% by weight of fly ash, in the second short basalt fibres were added as 2% by weight of fly ash and the third functioned as a control series without any fibres. Each series of samples were tested on compressive strength after 28, 14 and 7 days, and specimen density was determined. Additionally, microstructural analysis was carried out after 28 days. The results show that the addition of basalt fibres can improve the mechanical properties of geopolymer composites. Keywords: geopolymer, basalt fibre, composites, fire resistance

scholarly journals INFLUENCE OF PEAT WATER ON MECHANICAL PROPERTIES OF COCONUT SHELL AND FLY ASH BASED CONCRETE

2019 ◽  
Vol 7 (2) ◽  
pp. 102-108
Author(s):  
Yulin Patrisia ◽  
Topan Eka Putra
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Raw Material ◽  
Coconut Shell ◽  
Partial Replacement ◽  
Plain Water ◽  
Fine Aggregate ◽  
Coconut Shells

This study aimed to determine the influence of peat water on the mechanical properties of the paving block (compressive strength and water absorption) using coconut shell waste and fly ash as raw material. The background of the research were the lack utilization of fly ash, preparation for the handling and utilization of fly ash from power station at Pulang Pisau and Tumbang Kajuei (under construction), and the utilization of coconut shell to be more effective and economical. Paving block specimens were immersed in peat water to determine the effect of peat water and the rest were immersed in plain water. This experiment used fly ash as a partial replacement of cement and 2% coconut shell as a partial replacement of fine aggregate. The results of the analysis showed that: (a) Paving block using fly ash and coconut shells which were immersed in plain water experienced the increase in compressive strength and the decrease in water; (b) Paving block using fly ash and coconut shells soaked in peat water showed that by the increase of age, compressive strength was decrease and water absorption was increase; (c) The compressive strength of paving block specimens immersed in plain water and peat water showed relatively similar values at 7 and 28 days age, (d). Water absorption in paving block specimens soaked both in plain water and peat water showed relatively similar values at 7 days age, but at 28 days age the specimens immersed in peat water had greater water absorption.

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