Effect of the Ca-to-Si ratio on the properties of autoclaved aerated concrete containing coal fly ash from circulating fluidized bed combustion boiler

Song, Yali; Guo, Chuanchuan; Qian, Jueshi; Ding, Tian

doi:10.1016/j.conbuildmat.2015.02.077

Cited by 70 publications

(27 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They concluded that the strength of paste or foam concrete with stacked FBCFA is low, indicating that FA must be utilized as soon as possible. Song et al [34] found that the maximum bulk density and compressive strength of AAC containing FBCFA are higher than those of AAC containing PCC fly ash, and the volume stability of AAC containing FBCFA is superior to that of AAC containing PCC fly ash. Song et al [124] confirmed that autoclave curing can effectively limit the expansion of anhydrite in FBCFA.…”

Section: Aerated Concretementioning

confidence: 99%

Utilization of Fly Ashes from Fluidized Bed Combustion: A Review

et al. 2020

View full text Add to dashboard Cite

Traditionally fly ash is thought to be glassy, spherical particle originating from pulverized coal combustion (PCC) at temperature up to 1700 °C. However, nowadays fluidized bed combustion (FBC) technology is spreading quickly around the world as it is an efficient and environmentally friendly method. FBC is also able to utilize mixtures of low-grade solid fuels (e.g., coal, lignite, biomass, and waste) that have fluctuating quality, composition, and moisture contents. However, this leads to a high variation in the produced fly ash quality, unlike PCC fly ash, and hence challenges when attempting to utilize this fly ash. In this study, the utilization of fluidized bed combustion fly ash (FBCFA) was reviewed using the Scopus database. The most promising utilization target for FBCFA from biomass combustion is as a fertilizer and soil amendment. In construction, the FBCFA from various fuels is utilized as cement replacement material, in non-cement binders, as lightweight aggregates and cast-concrete products. Other types of construction applications include mine backfilling material, soil stabilizer, and road construction material. There are also other promising applications for FBCFA utilization, such as catalysts support material and utilization in waste stabilization.

show abstract

Section: Aerated Concretementioning

confidence: 99%

Utilization of Fly Ashes from Fluidized Bed Combustion: A Review

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The solubility of SiO 2 and CaO in water depending on temperature [9] cost of production [3]. The use of fluidized bed combustion ashes containing coal residues influences the hydrate structure and the AAC porosity [4].…”

Section: F I G U R Ementioning

confidence: 99%

Influence of secondary raw materials on synthesis of tobermorite in lime–silicate composite

et al. 2018

View full text Add to dashboard Cite

Crystalline calcium silicate hydrate (CSH) phases, primarily tobermorite, arise in the microstructure of autoclaved aerated concretes (AACs) during autoclaving, which affects the concrete's important characteristics. Calcium oxide/hydroxide and silicon oxide are the feedstocks for the hydrothermal reactions. When producing AACs, aside from commonly used raw materials, it is also possible to utilize secondary raw materials rich in silicon oxide. The use of such secondary raw materials provides the opportunity for the construction industry to lower its impact on the environment. This work describes the investigation of individual added secondary raw materials' influence on the microstructure of AAC. The tested materials were as follows: high-temperature fly ash, FBC ash, slag, ground container glass, and zeolite. The materials were mixed with quicklime at a molar ratio of calcium oxide to silicon oxide of 0.73 and 1.0. Autoclave reactors were used for the synthesis of tobermorite under laboratory conditions. Autoclaving took place at 170 and 190 • C with hydrothermal soaking times of 4, 8, and 16 h. The additive with the most significant impact on microstructure was fly ash, while ground container glass showed the greatest influence on mechanical characteristics. K E Y W O R D S autoclaved aerated concrete, fly ash, glass, secondary raw material, zeolite How to cite this article:Černý V, Kulísek K, Húšt'avová J. Influence of secondary raw materials on synthesis of tobermorite in lime-silicate composite. ce papers. 2018;2:439-444. https://doi.

show abstract

“…The compressive strength and bulk density were analyzed for physical/mechanical properties (Figure 1 The existing resources expect a decrease in the compressive strength with an increased content of FBC fly ash. 10,11,16 The compressive strength of the samples is the highest at a 10-% FBC fly-ash substitution. With an increased substitution, the strength is slightly decreased.…”

Section: Physical/mechanical Propertiesmentioning

confidence: 99%

“…This trend indicates a higher bulk density of the non-crystalline CSH phases formed in the presence of FBC fly ash. 16 Further explanation of the bulk density increase may be due to the loss of lime at higher FBC fly ash substitutions. The aluminum powder reacts to form a lower volume of hydrogen.…”

Section: Physical/mechanical Propertiesmentioning

confidence: 99%

Experimental study of autoclaved aerated concrete using circulating fluidized-bed combustion fly ash

Šebestová¹,

Černý²,

Drochytka³

2020

Mater. Tehnol.

View full text Add to dashboard Cite

The research deals with the possibility of maximum utilization of FBC fly ash in AAC technology and its impact on the properties of AAC. In the research, fly ash was used as a partial substitute for binder components in the AAC formulation. The amount of fly ash substitution was chosen on a scale of 10 % to 100 %. Physical-mechanical properties such as compressive strength and bulk density were determined on autoclaved samples. XRD analysis, SEM/EDX analysis were performed. Using these analyses, the change in the microstructure of autoclaved aerated concrete was monitored with increasing amount of FBC fly ash used. EDX microstructural tests have confirmed the incorporation of aluminum ions into the crystalline CSH. Further, an amount of crystalline tobermorite in the samples was observed which was almost constant up to 50 % of the FBC substitution. Compressive strength also began to decline significantly when the 50 % FBC fly ash substitution threshold was exceeded. The results thus show that the maximum FBC fly ash substitution is possible up to 50 %.Uporaba dimni{kega pepela, nastalega med zgorevanjem premogovega prahu v vrtin~asti plasti (CFBC) v izdelkih za gradbeni{tvo, je zahtevna zaradi njegove visoke vsebnosti`vepla. Mikrostruktura v avtoklavih prezra~enega betona (AAC) pa se spremeni v hidrotermalnih pogojih in tvorijo se kristalini~ni kalcij-silikatni hidrati (CSH). Ti so sposobni vezati v svojo strukturo kalcijev sulfat, ki ga vsebuje CFBC dimni{ki pepel. V raziskavi avtorji ugotavljajo kak{na je {e maksimalna mo`na koli~ina dodanega CFBC dimni{kega pepela v beton, izdelan z AAC tehnologijo in njen vpliv na lastnosti tako izdelanega AAC. V raziskavi so avtorji nadome{~ali`ivo apno z dimni{kim pepelom v skladu z AAC receptom. Nato so iz izdelanega betona naredili preizku{ance in dolo~ili njegove fizikalno-mehanske lastnosti, kot sta: tla~na trdnost in volumska gostota. Rezultati raziskave jasno ka`ejo mo`nost uporabe nadomestka v obliki dimni{kega pepela v koli~ini do 50 %. Nadalje so izvedli {e XRDin SEM/EDX-analize, ki so potrdile spremembe mikrostrukture prezra~enega betona zaradi uporabe pove~ane koli~ine CFBC dimni{kega pepela. EDX mikrostrukturne analize so potrdile vgradnjo aluminijevih ionov v kristalini~ni CSH. Klju~ne besede: v avtoklavih prezra~eni beton (AAC), zgorevanje premoga v vrtin~asti plasti (CFBC), dimni{ki pepel, tobermorit, zmanj{anje emisij 157

show abstract

Effect of the Ca-to-Si ratio on the properties of autoclaved aerated concrete containing coal fly ash from circulating fluidized bed combustion boiler

Cited by 70 publications

References 25 publications

Utilization of Fly Ashes from Fluidized Bed Combustion: A Review

Utilization of Fly Ashes from Fluidized Bed Combustion: A Review

Influence of secondary raw materials on synthesis of tobermorite in lime–silicate composite

Experimental study of autoclaved aerated concrete using circulating fluidized-bed combustion fly ash

Contact Info

Product

Resources

About