Properties and durability of concrete containing fluidized bed combustion (FBC) fly ash

2020 ◽  
Vol 258 ◽  
pp. 119663 ◽  
Author(s):  
Mona Zahedi ◽  
Khashayar Jafari ◽  
Farshad Rajabipour
Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2527
Author(s):  
Natalia Wielgus ◽  
Jan Kubica ◽  
Marcin Górski

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.


2014 ◽  
Vol 1054 ◽  
pp. 148-153
Author(s):  
Tereza Otcovská ◽  
Pavel Padevět

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.


Author(s):  
Karolina Knapik ◽  
Joanna Bzówka

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.


2020 ◽  
Author(s):  
Natalia Paszek ◽  
Marcin Górski

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


Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 690
Author(s):  
Artur Łagosz ◽  
Tomasz Tracz ◽  
Radosław Mróz

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%.


2015 ◽  
Vol 1106 ◽  
pp. 29-32
Author(s):  
Denisa Orsakova ◽  
Rudolf Hela ◽  
Petr Novosad ◽  
Jaroslav Valek

One of the possibilities how to activate fly ash in cement composites is to add calcium oxide as a chemical activator. This addition can improve pH of composites. Because fluidized bed combustion (FBC) fly ash contain around 15% of calcium oxide, we decided to add FBC fly ash into binder system of cement composite with classic fly ash.Three mixtures were designed. First one contain in binder system only cement and classic fly ash. In second and third mixture was part (25% resp. 50%) of classic fly ash replaced by FBC fly ash. Consistency, shrinkage, compressive strength and freeze-thaw resistance were tested. Microstructure was detected by XRD and TG analyses.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3106
Author(s):  
Tomasz Kalak ◽  
Kinga Marciszewicz ◽  
Joanna Piepiórka-Stepuk

Recently, more and more attention has been paid to the removal of nickel ions due to their negative effects on the environment and human health. In this research, fly ash obtained as a result of incineration of municipal sewage sludge with the use of circulating fluidized bed combustion (CFBC) technology was used to analyze the possibility of removing Ni(II) ions in adsorption processes. The properties of the material were determined using analytical methods, such as SEM-EDS, XRD, BET, BJH, thermogravimetry, zeta potential, SEM, and FT-IR. Several factors were analyzed, such as adsorbent dose, initial pH, initial concentration, and contact time. As a result of the conducted research, the maximum sorption efficiency was obtained at the level of 99.9%. The kinetics analysis and isotherms showed that the pseudo-second order equation model and the Freundlich isotherm model best suited this process. In conclusion, sewage sludge fly ash may be a suitable material for the effective removal of nickel from wastewater and the improvement of water quality. This research is in line with current trends in the concepts of circular economy and sustainable development.


Sign in / Sign up

Export Citation Format

Share Document