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.

scholarly journals Shotcrete using ternary binder made from coal combustion products: from lab tests to an application

2021 ◽  
Vol 1205 (1) ◽  
pp. 012004
Author(s):  
Vít Šmilauer ◽  
Radoslav Sovják ◽  
Šárka Pešková ◽  
Rostislav Šulc ◽  
František Škvára ◽  
...  
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Coal Combustion ◽  
Combustion Products ◽  
Strength Gain ◽  
Hydration Products ◽  
Fluidized Bed Combustion ◽  
Space Filling ◽  
Coal Combustion Products ◽  
Fbc Fly Ash

Abstract The paper presents a ternary binder development and its utilization in shotcrete. The binder is made from fluidized bed combustion (FBC) fly ash, siliceous fly ash, and Ca(OH)2 addition, now available under the name Sorfix. XRD and TGA identified ettringite and C-S-H as two main hydration products. In addition, thermodynamic modeling verified robustness in terms of space-filling capabilities when varying input oxide composition. Since alkali-free accelerators produce mostly ettringite in Portland-based systems, a fraction of Portland cement was advantageously replaced with the ternary binder, forming early ettringite as well. Extensive testing led to 45% replacement of Portland cement, following J2 curve for early strength gain used commonly in shotcrete tunnel linings. The shotcrete was successfully tested in a mock-up experiment in a 2 m3 Prague served for the full-scale application, utilizing over 1000 tons of Sorfix and saving over 700 tons of CO2

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 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 Desulfurisasi dan Penyerapan Merkuri secara Simultan dari Batubara Peringkat Rendah (Aceh Barat) untuk Aplikasi Power Plant dengan Adsorben Zeolit

2019 ◽  
Vol 7 (1) ◽  
pp. 73
Author(s):  
Yuanda Wattimena ◽  
Asri Gani ◽  
Medyan Riza
Keyword(s):  
Stainless Steel ◽  
Fly Ash ◽  
Power Plant ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Coal Combustion ◽  
Bottom Ash ◽  
Tube Furnace ◽  
Fluidized Bed Combustion ◽  
Gas Combustion

Adsorpsi emisi pembakaran batubara dengan menggunakan adsorben zeolit pada jenis briket dan pulverized telah dilakukan. Penelitian ini bertujuan untuk mengurangi emisi gas SO2 dan logam Hg yang berbahaya apabila rilis di udara bebas dengan cara menggunakan adsorben zeolit untuk kecendrungan emisi menjadi bottom ash yang lebih terkendali. Pengujian ini fokus mengevaluasi rasio optimal rasio adsorben terhadap jumlah batubara terhadap performa penyerapan, sehingga penggunaannya tidak mengurangi nilai bakar batubara. Prosedur pembakaran ekspremintal awal dimulai dari pencampuran batubara dan zeolit dengan rasio 4%, 6%, 8%, 10%  dan 12%  yang dibagi dalam bentuk briket dan pulverized. Kedua jenis sampel dibakar secara berurutan pada electrical stainless steel reaction tube furnace pada kondisi temperatur pembakaran Fludized Bed Coal Combustion yaitu 600oC, 700oC, dan 800oC dengan laju alir udara disesuaikan. Flue gas hasil pembakaran yang keluar dari outlet dianalisa menggunakan Gas Combustion and Emission Analyzer (E4400, E-Instrument). Logam Hg yang yang diserap oleh zeolit pada Bottom Ash dianalisa menggunakan NIC Mercury SP Anlayzer. Hasil pengujian menunjukan kinerja zeolit terhadap kapasitas penyerapan logam Hg untuk pembakaran batubara pulverized pada temperatur pembakaran  600oC, 700oC dan 800oC masing-masing didapat pada angka 33,6, 19,25 dan 9,97 ppb/gr serta pada pembakaran briket batubara  masing-masing didapat sebesar 59,83, 37,8 dan 24,22 ppb/gr. Secara simultan untuk mengurangi emisi SO2 dan logam berat Hg pada fly ash untuk temperatur pembakaran Fludized Bed Coal Combustion rasio optimum berkisar antara 6%-8% adsoben zeolit dari jumlah massa batubara Kaway XVI Kabupaten Aceh Barat. Kata kunci:adsorpsi,  fluidized bed combustion, zeolit, briket, pulverized

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 Extending the Life Cycle of Cement Binders by Partially Replacing Portland Cement with Different Types Fluidized Bed Combustion Fly Ash

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 690
Author(s):  
Artur Łagosz ◽  
Tomasz Tracz ◽  
Radosław Mróz
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Fluidized Bed ◽  
Sulfate Solution ◽  
Curing Temperature ◽  
Fluidized Bed Combustion ◽  
Sulfate Resistance ◽  
Granulated Blast Furnace Slag ◽  
Near Future ◽  
Fbc Fly Ash

A significant reduction in the CO2 emission associated with cement production is obtained by partially replacing Portland cement with supplementary cementing materials (SCM’s): e.g., siliceous fly ash or granulated blast furnace slag. In the near future, the limited availability of these materials will do more attractive to use ashes from combustion in fluidized bed boilers, which currently are mainly deposited in various landfills. Paper identifies the effect of Fluidized Bed Combustion (FBC) fly ash from both hard and brown coal combustion on the durability of mortars exposed to sodium and magnesium sulfate solution at different curing temperature: 20 and 5 °C. The evaluation was based on the results of long-term linear changes of mortar samples made with Portland cement and different amounts of FBC fly ash addition stored in a corrosive environment, as well as the evaluation of the type of formed corrosion products using XRD and microstructural studies (SEM/EDS). It has been shown that amount of FBC fly ashes used in binders significantly determines sulfate resistance of prepared cements as well as its chemical composition. By using fluidized ashes, the sulfate resistance of cement binders can be achieved with their content even of 15%.

scholarly journals The Influence of Fluidized Bed Combustion Fly Ash on the Phase Composition and Microstructure of Cement Paste

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2838
Author(s):  
Michał A. Glinicki ◽  
Daria Jóźwiak-Niedźwiedzka ◽  
Mariusz Dąbrowski
Keyword(s):  
Phase Composition ◽  
Fly Ash ◽  
Fluidized Bed ◽  
Cement Paste ◽  
Power Plants ◽  
Circulating Fluidized Bed ◽  
Thermal Analyses ◽  
Hardened Cement ◽  
Fluidized Bed Combustion ◽  
Cement Pastes

Fly ashes from coal combustion in circulating fluidized bed boilers in three power plants were tested as a potential additive to cement binder in concrete. The phase composition and microstructure of cement pastes containing fluidized bed fly ash was studied. The fractions of cement substitution with fluidized bed fly ash were 20% and 30% by weight. X-ray diffraction (XRD) tests and thermal analyses (derivative thermogravimetry (DTG), differential thermal analysis (DTA) and thermogravimetry (TG)) were performed on ash specimens and on hardened cement paste specimens matured in water for up to 400 days. Quantitative evaluation of the phase composition as a function of fluidized bed fly ash content revealed significant changes in portlandite content and only moderate changes in the content of ettringite.

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