Porosity and Permeability Analysis of Sludge Stabilised with Fly Coal Ash and Portland Cement

2011 ◽  
Vol 378-379 ◽  
pp. 389-392
Author(s):  
Tomáš Daněk ◽  
Jan Thomas ◽  
Jan Jelínek ◽  
Jiří Mališ
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Steel Industry ◽  
Coal Fly Ash ◽  
Coal Ash ◽  
Iron And Steel Industry ◽  
Iron And Steel ◽  
Permeability Characteristics ◽  
Porosity And Permeability

The aim of this study was to quantify the properties of sludge from iron and steel industry with high content of heavy metals, which has been solidified/stabilised by coal fly ash and Portland cement. The mixtures of sludge and coal fly ash and/or cement after of curing were used for tests. The porosity and permeability characteristics of solidified sludge were examined. To understand the behaviour of mixtures in the long term, the prepared mixtures were tested after 14, 28, 56 and 120 days.

Strength Properties of Sludge Solidified with Fly Coal Ash and Portland Cement

2011 ◽  
Vol 378-379 ◽  
pp. 439-442
Author(s):  
Tomáš Daněk ◽  
Jan Thomas ◽  
Jiří Mališ ◽  
Jan Jelínek
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Uniaxial Compressive Strength ◽  
Coal Fly Ash ◽  
Coal Ash ◽  
Strength Properties ◽  
Mixture Composition ◽  
Metallurgical Production

The paper deals with the properties of mixtures on the base of fly ash and sludge from the metallurgical production. The mixture composition of this group is grounded in the knowledge acquired during testing of various mixtures. The mixtures of sludge and coal fly ash and/or cement after of curing were used for tests. The uniaxial compressive strength of solidified sludge was examined. To understand the behaviour of mixtures in the long term, the prepared mixtures were tested after 14, 28, 56 and 120 days.

scholarly journals Coal ash Portland Cement Mortars Sulphate Resistance

2021 ◽  
Vol 7 (1) ◽  
pp. 98-106
Author(s):  
Esperanza Menéndez ◽  
Cristina Argiz ◽  
Miguel Ángel Sanjuán
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Coal Fly Ash ◽  
Electrical Power ◽  
Bottom Ash ◽  
Coal Ash ◽  
Sodium Sulphate ◽  
Sulphate Attack ◽  
Coal Bottom Ash ◽  
Cement Mortars

Coal fly ash (CFA), coal bottom ash (CBA) are residues produced in thermo-electrical power stations as result of the coal combustion in the same boiler. Therefore, some characteristics of the coal fly ash (CFA) are comparable with those of the coal bottom ash (CBA). Nevertheless, coal bottom ash size is larger than coal fly ash one. Consequently, it was found that it is necessary to grind the coal bottom ash (CBA) to reach a similar size to that one of the CFA. The objective of this paper is to evaluate the performance of Portland cement mortars made with coal fly ash (CFA), coal bottom ash (CBA) or mixes (CFA+CBA), against sulphate attack. The methodology is based on the expansion of slender bars submerged in a sodium sulphate solution (5%) according to the ASTM C-1012/C1012-13 standard. It has been found that mortars elaborated with CEM I 42.5 N (without ashes) presented the largest expansion (0.09%) after a testing period of 330 days. Mortars made with CEM II/A-V exhibited lower expansion (0.03%). Summing up, it can be established that mortar expansion decreases when the coal ash amount increases, independently of the type of coal ash employed. The novelty of this paper relies on the comparison between the performances of Portland cement mortars made with coal fly ash (CFA) or coal bottom ash (CBA) exposed to external sulphate attack. Doi: 10.28991/cej-2021-03091640 Full Text: PDF

scholarly journals Reactivity of Ground Coal Bottom Ash to Be Used in Portland Cement

J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 223-232
Author(s):  
Esperanza Menéndez ◽  
Cristina Argiz ◽  
Miguel Ángel Sanjuán
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Bottom Ash ◽  
Blended Cement ◽  
Coal Ash ◽  
Pozzolanic Reaction ◽  
Natural Sand ◽  
Coal Bottom Ash ◽  
Novel Material ◽  
Pozzolanic Properties

Ground coal bottom ash is considered a novel material when used in common cement production as a blended cement. This new application must be evaluated by means of the study of its pozzolanic properties. Coal bottom ash, in some countries, is being used as a replacement for natural sand, but in some others, it is disposed of in a landfill, leading thus to environmental problems. The pozzolanic properties of ground coal bottom ash and coal fly ash cements were investigated in order to assess their pozzolanic performance. Proportions of coal fly ash and ground coal bottom ash in the mixes were 100:0, 90:10, 80:20, 50:50, 0:100. Next, multicomponent cements were formulated using 10%, 25% or 35% of ashes. In general, the pozzolanic performance of the ground coal bottom ash is quite similar to that of the coal fly ash. As expected, the pozzolanic reaction of both of them proceeds slowly at early ages, but the reaction rate increases over time. Ground coal bottom ash is a promising novel material with pozzolanic properties which are comparable to that of coal fly ashes. Then, coal bottom ash subjected to an adequate mechanical grinding is suitable to be used to produce common coal-ash cements.

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