Characterization and quantification of the pozzolanic reactivity of natural and non-conventional pozzolans

Yoon, Jinyoung; Jafari, Khashayar; Tokpatayeva, Raikhan; Peethamparam, Sulapha; Olek, Jan; Rajabipour, Farshad

doi:10.1016/j.cemconcomp.2022.104708

Cited by 31 publications

(8 citation statements)

References 52 publications

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“…There are a wide range of tests used strictly to evaluate the pozzolanic activity and, among them, analyses are arranged as direct and indirect methods [ 19 , 30 ]. The methods categorized as direct monitor the presence of C-H (Ca(OH) 2 ) and its subsequent reduction over time as the pozzolanic reaction proceeds.…”

Section: Analysis Of Pozzolanic Activitymentioning

confidence: 99%

“…It is important to emphasize that the clays used must be predominantly kaolinitic. The purpose of calcination is the transformation of kaolinite into metakaolinite, which occurs between 450 and 900 • C. Thus, it is possible to observe that crude clay minerals with low chemical reactivity, in general, are not applied as a direct use without an activation treatment, such as thermal activation by calcination, for example [19,20]. The calcination at higher temperatures can cause the transformation of metakaolin into mullite.…”

Section: Introductionmentioning

confidence: 99%

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Methods for Evaluating Pozzolanic Reactivity in Calcined Clays: A Review

Pinheiro¹,

Alexandre²,

Xavier³

et al. 2023

Materials

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The search for alternative materials to replace ordinary Portland cement has been the object of work that enhances the investigation of the use of pozzolanic materials and the reduction of the carbon footprint with supplementary cementitious materials. However, not all materials are available to meet the large-scale demand for cement replacement. A relevant exception is the calcined clay, a material found worldwide that, when subjected to appropriate heat treatment, presents pozzolanic reactivity and can be used as a supplementary material to cement. This review presents, through a systematic search, methods for measuring the pozzolanic reactivity of calcined clays, namely, direct, indirect, qualitative, quantitative, chemical and physical methods such as electrical conductivity (Lùxan), the force activity index, the modified Chapelle, R3, Frattini test, thermal analysis, X-ray diffraction and X-ray fluorescence spectrometry. The most usual methods to assess the pozzolanic reactivity of calcined clays were exposed and analyzed. It should be pointed out that there is greater use of the Frattini and modified Chapelle methods as well as the analysis of the mechanical strength behavior of the material in cementitious matrices. X-ray diffraction and thermal analysis were exposed as the most used correlation methods but it was also concluded that different tests are needed to generate accurate results.

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Section: Analysis Of Pozzolanic Activitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Methods for Evaluating Pozzolanic Reactivity in Calcined Clays: A Review

Pinheiro¹,

Alexandre²,

Xavier³

et al. 2023

Materials

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“…In 2016, an indirect test method called Rapid, Relevant, and Reliable (R 3 ) was introduced to assess the pozzolanic reactivity of calcined clays and to identify other pozzolanic materials [30,31]. The R 3 test offers two methods for the analysis of a paste of pozzolanic material and lime (2:1 mixture of pozzolan and lime and a water-to-solid ratio of 1.2).…”

Section: Introductionmentioning

confidence: 99%

Comprehensive Review of Direct and Indirect Pozzolanic Reactivity Testing Methods

Elyasigorji,

Farajiani,

Hajipour Manjili

et al. 2023

Buildings

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The production of portland cement is among the major contributors to greenhouse gas emissions that adversely affect the environment. Identifying sustainable materials to partially replace portland cement in concrete, such as pozzolanic materials, is crucial in addressing this issue. These materials mainly consist of silica and alumina that react with the available calcium hydroxide to form strength-bearing phases such as calcium silicate hydrates. Understanding the degree of pozzolanic reactivity of materials using efficient reactivity test methods is an important consideration. The paper thoroughly reviews the available literature related to direct and indirect pozzolanic reactivity test methods that have been utilized over the years. Direct methods quantify the amount of consumed calcium hydroxide, whereas indirect methods assess changes in the physical properties of the specimen due to pozzolanic reactions. The aim of this paper is to identify affordable, time-saving, and effective direct and indirect methods. Based on this study, the Frattini, electrical conductivity, and pH tests are considered the most time-efficient methods to assess pozzolanic materials. Electrical conductivity and pH tests are also easy to perform. In contrast, other methods are more time-consuming.

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“…In summary, the binder formed by mixing LS, FA, and DG in ordinary Portland cement (OPC) is theoretically a new type of binder that can substantially improve the activity of volcanic ash, has strong cementation ability, and is conducive to improving the compressive strength of backfilling [24][25][26]. The purpose of this study is to explore the feasibility of LS, FA, and DG for cementing lepidolite fine-grained tailings for backfilling.…”

Section: Introductionmentioning

confidence: 99%

Lithium Slag and Solid Waste-Based Binders for Cemented Lithium Mica Fine Tailings Backfill

Li,

Huang,

et al. 2023

Materials

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To mitigate the adverse effects of fine-grained lithium mica tailings and other solid wastes generated from the extraction of lithium ore mining, as well as the limitations of traditional cement-based binders for lithium mica fine tailings, this study explores the feasibility of using a binder composed of ordinary Portland cement, lithium slag, fly ash, and desulfurization gypsum to stabilize lithium fine tailings into cemented lithium tailings backfill. Compared with traditional cementitious binders, an extensive array of experiments and analyses were conducted on binders formed by various material proportion combinations, employing uniaxial compressive strength tests, microstructural morphology, grayscale analyses, and flowability tests. The results show the following: (1) In this study, an LSB binder exhibiting superior mechanical properties compared to traditional cementitious binders was identified, with an optimal OPC:LS:FA:DG ratio of 2:1:1:1. (2) In the context of cemented lithium mica fine tailings, the LSB-CLTB material exhibits higher unconfined compressive strength and lower self-weight compared to OPC-CLTB materials. At a binder content of 10 wt%, the UCS values achieved by the LSB-CLTB material at curing periods of 7 days, 14 days, and 28 days are 0.97 MPa, 1.52 MPa, and 2.1 MPa, respectively, representing increases of 40.6%, 34.5%, and 44.8% over the compressive strength of OPC-based materials under the same conditions. (3) The LSB binder not only exhibits enhanced pozzolanic reactivity but also facilitates the infilling of detrimental pores through its inherent particle size and the formation of AFt and C-(A)-S-H gels via hydration reactions, thereby effectively improving the compressive strength performance of fine-grained tailings backfill.

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Characterization and quantification of the pozzolanic reactivity of natural and non-conventional pozzolans

Cited by 31 publications

References 52 publications

Methods for Evaluating Pozzolanic Reactivity in Calcined Clays: A Review

Methods for Evaluating Pozzolanic Reactivity in Calcined Clays: A Review

Comprehensive Review of Direct and Indirect Pozzolanic Reactivity Testing Methods

Lithium Slag and Solid Waste-Based Binders for Cemented Lithium Mica Fine Tailings Backfill

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