Fly Ash-Desulfurization Gypsum Mortar and Concrete Part I: Mix Proportions and Hydration

2011 ◽  
Vol 250-253 ◽  
pp. 809-816
Author(s):  
Yu Chen ◽  
Ying Li Gao
Keyword(s):  
Fly Ash ◽  
Flue Gas ◽  
Hydration Process ◽  
Cement Stone ◽  
Composite Binder ◽  
Strength Concrete ◽  
Concrete Hydration ◽  
Concrete Part ◽  
Flue Gas Desulphurization

Fly ash (FA) and flue gas desulphurization gypsum (FGD) were blended in proportion into a new composite binder added with cement, lime and some modifiers. In the paper, the mix proportions of composite binder with low-quality FA and FGD were studied. FA-FGD more than 80% with FA:FGD 3:2 was suggested for mortar, plastering and slurry while FA:FGD 2:1 and FA-FGD 30~40% was recommended for middle-strength concrete. Hydration process of typical mixtures of FA-FGD paste was investigated through SEM and XRD tests. The conclusion could be made that FA showed much improved pozzolana activity especially at early ages due to the existence of FGD as an ideal sulfate activator, which also crystallized later to strengthen the hardened paste. The microstructure of hydrated FA-FGD paste was more excellent than that of neat cement stone or one blended with the same percentage of pure FA.

Fly Ash-Desulfurization Gypsum Mortar and Concrete Part II: Performances

2011 ◽  
Vol 243-249 ◽  
pp. 6880-6886 ◽  
Author(s):  
Yu Chen ◽  
Ying Li Gao
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Mass Loss ◽  
Drying Shrinkage ◽  
Strength Development ◽  
Composite Binder ◽  
Strength Concrete ◽  
Concrete Part ◽  
Standard Limit ◽  
Good Workability

FA-FGD mortar and concrete were manufactured and tested the main performances. With WFA-FGD taking 80~85% of the total composite binder by mass, mortar used in buildings was provided with good workability, enough mechanical properties specified for masonry in China, low drying shrinkage and strong sulfate corrosion, which was suitable for plastering or coating inside and outside walls. With LFA-FGD more than 30% in proportion, middle-strength concrete showed satisfactory workability with no segregation, no bleeding and low slump loss, stable strength development and low brittleness, about 60% of the domestic standard limit of wear mass loss in the specified test, good impermeability as well as excellent cracking resistance.

Activation of rejected fly ash using flue gas desulphurization (FGD) sludge

2003 ◽  
Vol 18 (4) ◽  
pp. 84-88 ◽  
Author(s):  
Qiao Xiu-chen ◽  
Poon Chisun ◽  
Lin Zong-shou
Keyword(s):  
Fly Ash ◽  
Flue Gas ◽  
Flue Gas Desulphurization

scholarly journals Influence of Sodium Hydroxide on the Properties of Uncalcined Flue Gas Desulphurization Gypsum-Slag Composite Binder

2014 ◽  
Vol 26 (6) ◽  
pp. 1651-1654
Author(s):  
Baoxiang Jiao ◽  
Baolong Jiao ◽  
Yushou Li ◽  
Yuhua Li ◽  
Wei Guo ◽  
...  
Keyword(s):  
Sodium Hydroxide ◽  
Flue Gas ◽  
Composite Binder ◽  
Flue Gas Desulphurization

Study on Flue Gas Desulphurization Gypsum Plaster

2011 ◽  
Vol 71-78 ◽  
pp. 842-846
Author(s):  
Miao Miao Chen ◽  
Yun Wei Yu ◽  
Chun Hua Feng ◽  
Dong Xu Li
Keyword(s):  
Fly Ash ◽  
Flue Gas ◽  
Water Retention ◽  
Setting Time ◽  
Strength Loss ◽  
Optimum Level ◽  
Fgd Gypsum ◽  
Gypsum Plaster ◽  
Calcined Gypsum ◽  
Flue Gas Desulphurization

Flue gas desulphurization (FGD) gypsum and fly ash are two kinds of solid waste in coal-fired power plant. The possible displacement content of fly ash in gypsum plaster was investigated in this paper. The effect of various chemicals retarders, such as Citric acid, sodium citrate and SC gypsum retarder, and water retention agent on the setting time, flexural strength and compressive strength of gypsum plaster was also studied. The results demonstrate that gypsum plaster has maximum mechanical properties and enough setting time at the rate of 20% fly ash replacing calcined gypsum; SC gypsum retarder effectively delays the setting time and has lower strength loss; The optimum level of water-retention agent for effective utilization of gypsum plaster is 0.2%.

scholarly journals Preliminary Examination of the System Fly Ash-Bottom Ash-Flue Gas Desulphurization Gypsum-Portland Cement-Water for Road Construction

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
R. Tokalic ◽  
S. Marinkovic ◽  
P. Trifunovic ◽  
G. Devic ◽  
S. Zildzovic
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Flue Gas ◽  
Bottom Ash ◽  
Road Construction ◽  
Mineralogical Composition ◽  
Mass Ratio ◽  
Preliminary Examination ◽  
Potential Use ◽  
Flue Gas Desulphurization

This paper describes an investigation into the use of three power plant wastes: fly ash, flue gas desulphurization gypsum, and bottom ash for subbase layers in road construction. Two kinds of mixtures of these wastes with Portland cement and water were made: first with fly ash consisting of coarser particles (<1.651 mm) and second with fly ash consisting of smaller particles (<0.42 mm). The mass ratio of fly ash-Portland cement-flue gas desulphurization gypsum-bottom ash was the same (3 : 1 : 1 : 5) in both mixtures. For both mixtures, the compressive strength, the mineralogical composition, and the leaching characteristics were determined at different times, 7 and 28 days, after preparation. The obtained results showed that both mixtures could find a potential use for subbase layers in road construction.

scholarly journals Synthesis and Characterization of Zeolites Produced from Low-Quality Coal Fly Ash and Wet Flue Gas Desulphurization Wastewater

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1558
Author(s):  
Paulina Nowak ◽  
Barbara Muir ◽  
Agnieszka Solińska ◽  
Małgorzata Franus ◽  
Tomasz Bajda
Keyword(s):  
Fly Ash ◽  
Flue Gas ◽  
Coal Fly Ash ◽  
Environmental Pollutants ◽  
Textural Properties ◽  
Solution Concentration ◽  
Sorption Properties ◽  
X Ray ◽  
Synthetic Zeolites ◽  
Flue Gas Desulphurization

This study investigated a low-energy-consuming procedure for the synthesis of zeolite materials from coal fly ash (CFA). Materials containing zeolite phases, namely Na–X, Na–P1, and zeolite A, were produced from F–class fly ash, using NaOH dissolved in distilled water or in wastewater obtained from the wet flue gas desulphurization process, under atmospheric pressure at a temperature below 70 °C. The influence of temperature, exposure time, and alkaline solution concentration on the synthesized materials was tested. In addition, chemical, mineralogical, and textural properties of the obtained materials were determined by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and cation exchange capacity (CEC). Cd(II), Ni(II), NH4+ cation, and Se(VI) anion sorption experiments were conducted to compare the sorption properties of the produced synthetic zeolites with those of the commercially available ones. Zeolitization resulted in an increase of CEC (up to 30 meq/100 g) compared to raw CFA and enhanced the ability of the material to adsorb the chosen ions. The obtained synthetic zeolites showed comparable or greater sorption properties than natural clinoptilolite and synthetic Na–P1. They were also capable of simultaneously removing cationic and anionic compounds. The structural, morphological, and textural properties of the final product indicated that it could potentially be used as an adsorbent for various types of environmental pollutants.

scholarly journals HIGH STRENGTH CONCRETE FOR LEGO-BLOCKS

2021 ◽  
Vol 6 (5) ◽  
pp. 8-18
Author(s):  
V. Lesovik ◽  
M. Elistratkin ◽  
A. Sal'nikova
Keyword(s):  
High Strength Concrete ◽  
Basalt Fiber ◽  
High Strength ◽  
Maximum Efficiency ◽  
Cement Stone ◽  
Composite Binder ◽  
Positioning Systems ◽  
Strength Concrete ◽  
Fine Grained ◽  
Thin Walled

Lego technology is one of the modern construction solutions providing cost reduction, increasing architectural expressiveness and the pace of work. This is the development of groove-ridge positioning systems and connection of small-piece wall elements. Currently, the technology of Lego blocks is implemented on various types of building materials: ceramic and hyper-pressed non-fired bricks, blocks from various types of lightweight concrete, which have not found wide practical application due to an obvious shift in the balance of properties either towards aesthetics – brick, or thermal insulation - blocks. In this regard, a technology for producing multi-hollow thin-walled lego blocks based on self-compacting high-strength fine-grained concrete with various types of high-porous filling is proposed. In this paper, the compositions of high-strength concrete mixes for the manufacture of lego block frames are proposed. The main emphasis in the development is made on improving the manufacturability of their production and the maximum efficiency of using the clinker component. Overcoming the multicomponent problem is achieved by replacing traditional cement with a special all-in-one composite binder. Due to the unacceptability of traditional methods of dispersed reinforcement for producing thin-walled products from self-compacting fine-grained mixtures, it is proposed to carry out dispersed micro-reinforcement at the level of cement stone, for which a technology is developed and the optimal parameters of dispersion of glass and basalt fiber are determined. Thanks to this approach, reinforcing fibers are included in the composition of the composite binder itself, which ensures maximum manufacturability and an increase in compressive strength up to 20...25 %.

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