Review, Sampling, and Evaluation of Landfilled Fly Ash

Kaladharan, Gopakumar; Gholizadeh-Vayghan, Asghar; Rajabipour, Farshad

doi:10.14359/51716750

Cited by 12 publications

(3 citation statements)

References 38 publications

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“…In recent decades, there has been a growing demand for the use of this type of materials, which although they do not meet standards, these can be recycled in the concrete industry [ 20 ]. Some authors estimate that the infrastructure construction industry will have a growing demand for fly ash and it is expected to exceed 35 million tons by 2030, although it is projected that the supply will be only 14 million tons [ 20 , 42 ]. This enormous gap between supply and demand requires not only the recycling of fly ash that is being improperly disposed but also the use of biochar [ 20 ].…”

Section: Introductionmentioning

confidence: 99%

Use of biochar from rice husk pyrolysis: assessment of reactivity in lime pastes

Morales

Herrera

López

et al. 2021

Heliyon

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Section: Introductionmentioning

confidence: 99%

Use of biochar from rice husk pyrolysis: assessment of reactivity in lime pastes

Morales

Herrera

López

et al. 2021

Heliyon

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“…Rising shortfalls in the supply of conventional supplementary cementitious materials (SCMs) have resulted in a need to explore alternative SCMs [1,2]. Several alternative SCMs, including steel slags, ponded and reclaimed fly ashes, and zeolites have been studied in literature [3][4][5][6][7][8][9][10][11]. These materials are largely waste materials of negligible economic value and/or side stream products, which if not upcycled or utilized, would be landfilled or ponded, resulting in negative environmental consequences [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Mechanically activated mine tailings for use as supplementary cementitious materials

et al. 2021

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Two mine tailings are evaluated for their potential as supplementary cementitious materials. The mine tailings were milled using two different methods – ball milling for 30 minutes and disc milling for durations ranging from 1 to 15 minutes. The modified R3 test was carried out on the mine tailings to quantify their reactivity. The reactivity of the disc milled tailings is greater than those of the ball milled tailings. Strong correlations are obtained between milling duration, median particle size, amorphous content, dissolved aluminum and silicon, and reactivity of the mine tailings. The milling energy results in an increase in the fineness and the amorphous content, which do not appreciably increase beyond a disc milling duration of 8 minutes. The reactivity increases significantly beyond a certain threshold fineness and amorphous content. Cementitious pastes were prepared at 30% supplementary cementitious materials replacement level at a water-to-cementitious materials ratio of 0.40. No negative effects of the mine tailings were observed at early ages in cement pastes based on isothermal calorimetry and thermogravimetric analysis, demonstrating the potential for these materials to be used as supplementary cementitious materials.

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“…The materials which have the greatest global potential to reduce cement CO 2 emissions are limestone, fillers, tailings, calcined clays, natural pozzolans, and alternative fly ashes. Considerable research has been carried out on a variety of alternative SCMs [3,[6][7][8]. Because the number of available sources is large, there is significant merit in providing the ability to rapidly determine whether a material is an SCM or not.…”

Section: Introductionmentioning

confidence: 99%

Recent developments in reactivity testing of supplementary cementitious materials

Suraneni

2021

RILEM Tech Lett

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Identification and rapid characterization of novel supplementary cementitious materials (SCMs) is a critical need, driven by shortfalls in conventional SCMs. In this study, we present a discussion of recently developed reactivity tests – the R3 test, the modified R3 test, the lime strength test, and the bulk resistivity index test. These tests measure reactivity parameters such as heat release, bound water, calcium hydroxide consumption, strength, and bulk resistivity. All tests can screen inert from reactive materials. To additionally differentiate pozzolanic and latent hydraulic materials, two parameters, for example, calcium hydroxide consumption and heat release, are needed. The influences of SCM bulk chemistry, amorphous content, and fineness on measured reactivity are outlined. Reactivity test outputs can predict strength and durability of cement paste/mortar/concrete; however, caution must be exercised as these properties are influenced by a variety of other factors independent of reactivity. Thoughts are provided on using reactivity tests to screen materials for concrete durability.

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Review, Sampling, and Evaluation of Landfilled Fly Ash

Cited by 12 publications

References 38 publications

Use of biochar from rice husk pyrolysis: assessment of reactivity in lime pastes

Use of biochar from rice husk pyrolysis: assessment of reactivity in lime pastes

Mechanically activated mine tailings for use as supplementary cementitious materials

Recent developments in reactivity testing of supplementary cementitious materials

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