A review on fly ash characteristics – Towards promoting high volume utilization in developing sustainable concrete

Hemalatha, T.; Ramaswamy, Ananth

doi:10.1016/j.jclepro.2017.01.114

Cited by 538 publications

(212 citation statements)

References 125 publications

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“…Sodium hydroxide (Na ? , OH -) is also produced during the [16,19,36,43,49,60,74,103,110,115,116]. Ca(OH) 2 needed for the reaction may come from different sources: cement hydration, introduction of additional amount of Ca(OH) 2 into the system or as component of used supplementary cementitious material (e.g.…”

Section: Moderate Alkali Activationmentioning

confidence: 99%

Influence of selected activating methods on hydration processes of mixtures containing high and very high amount of fly ash

Wilińska

Pacewska

2018

J Therm Anal Calorim

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Binders containing fly ash as cement substitute have been used for many years. Typical amount of fly ash in cement composite does not exceed 35% of mass of binder. Replacement of substantial amount of cement mass by fly ash results in retardation of hydration of binder and deterioration of some concrete properties, e.g. delay in setting time and reduction in early compressive strength. These inconveniences may be reduced using proper method of activation. In this paper, possibilities to activate binding mixtures containing high and very high amount of fly ash and low amount of Portland cement were discussed basing on the literature reports as well as on our own research results. Several activating methods were described, such as mechanical activation, exchanging of part of components of binder (cement, fly ash or both of them) by more reactive fine-grained material, chemical activation by the use of alkaline activators as well as combined methods. Possibilities of using these methods were discussed in relation to amount of fly ash introduced as replacement of cement and kind of fly ash used. Usefulness of calorimetry and thermal analysis methods was also presented.

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Section: Moderate Alkali Activationmentioning

confidence: 99%

Influence of selected activating methods on hydration processes of mixtures containing high and very high amount of fly ash

Wilińska

Pacewska

2018

J Therm Anal Calorim

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“…The 500 Mt/year of coal fly ash presently landfilled could be reused to manufacture cement or concrete (Chindaprasirt et al, 2005;Duvallet et al, 2015;Hemalatha and Ramaswamy, 2017) if ash particle reactivity could be significantly enhanced. Such valorization would also help mitigate global warming by reducing the CO 2 emitted by the building materials industry.…”

Section: Introductionmentioning

confidence: 99%

“…In addition to the chemical composition of the ash, the vitreous phase content and the (SiO 2 /Al 2 O 3 ) reactive ratio, particle size is a factor to be borne in mind when determining a material's reactive potential. A number of studies mention the effect of fly ash particle size when used either as a supplementary cementitious material to lower the clinker factor (Paya et al, 1997;Chindaprasirt et al, 2005;Hemalatha and Ramaswamy, 2017) or as a precursor in the preparation of alkaline (OPC-less) cements (Fernández-Jiménez et al, 2005;Marjanovic et al, 2014;Duvallet et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Mechanical-Chemical Activation of Coal Fly Ashes: An Effective Way for Recycling and Make Cementitious Materials

et al. 2019

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This paper is wholly committed to resource efficiency through the valorization of waste from other industries, and more specifically fly ash as a raw material to produce concrete-like geopolymers. In particular, this study aimed to determine the effect of the physical and chemical characteristics of recycled coal fly ash used to manufacture alkaline cement on reaction kinetics and product microstructure and performance. The ash was mixed with 8 M NaOH and cured for 20 h at 85 • C and RH > 90% to form a compact paste, after which mechanical strength was determined and the reaction rate was calculated using isothermal conduction calorimetry. The findings showed that vitreous content (SiO 2 /Al 2 O 3 ), reactive and (especially) fineness play a very important role in both the development of cement mechanical strength and the composition and structure of the reaction products formed.

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“…Carbon dioxide is a major atmospheric pollutant emission from cement production industries, because one ton of clinker produces one ton CO2 emission into the atmosphere [2]. To control the pollution due to cement production, some of the industrial byproducts like FA, GGBS, RHA, SF and others are used as secondary cementitious materials [3][4][5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

A State of the Art on Red Mud as a Substitutional Cementitious Material

Venkatesh¹,

Madduru²,

Nerella³

2019

ACSM

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Red mud is a highly alkaline solid waste produced from the alumina refinery plants. Every year more than 300 million tons of red mud is producing throughout world. Disposal of a large quantity of red mud is very expensive and it creates contamination of neighbor lands, air and water bodies. Using red mud as a sustainable cementitious material in concrete is highly appreciable, because concrete is a second largest using material after water. Moreover, reduce the negative effect on environment due to red mud disposal as well as cement industries. The present paper conducted a critical review on bayer process of red mud, physical and chemical properties of red mud. And also workability, mechanical, durability and microstructure characterization of red mud when used in concrete as sustainable cementitious material. In the red mud iron oxide and alumina oxide are presented abundantly. Red mud accelerates the heat of hydration in concrete and it leads to strength enhancement in early ages. Increases the quantity of red mud in concrete reduces the workability but increases the strength of concrete. However, the chemical composition of red mud and its particle size helps to improve the durability property of concrete. Red mud offers more capable to arrest the chloride ions and other ions diffusion into concrete. Red mud minimizes the micro cracks and voids present in concrete by its particles size as well as bonding nature with other materials up to certain dosage of red mud used in concrete.

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A review on fly ash characteristics – Towards promoting high volume utilization in developing sustainable concrete

Cited by 538 publications

References 125 publications

Influence of selected activating methods on hydration processes of mixtures containing high and very high amount of fly ash

Influence of selected activating methods on hydration processes of mixtures containing high and very high amount of fly ash

Mechanical-Chemical Activation of Coal Fly Ashes: An Effective Way for Recycling and Make Cementitious Materials

A State of the Art on Red Mud as a Substitutional Cementitious Material

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