Rietveld Quantitative Phase Analysis of OPC Clinkers, Cements and Hydration Products

Aranda, Miguel A. G.; Torre, Ángeles G. De la; León‐Reina, Laura

doi:10.2138/rmg.2012.74.5

Cited by 141 publications

(74 citation statements)

References 189 publications

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“…The analysis of powder XRD data of hydrating blended cements has been largely limited to: (1) the quantification of the degree of hydration of the crystalline clinker phases, and (2) the formation of crystalline hydration products [3,66]. Hydrating cements are complex materials consisting of numerous coexisting phases, both residual anhydrous phases and hydration products that can each have variable composition and crystallinity.…”

Section: Xrdmentioning

confidence: 99%

TC 238-SCM: hydration and microstructure of concrete with SCMs

Scrivener¹,

et al. 2015

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This paper is the work of working group 2 of the RILEM TC 238-SCM. Its purpose is to review methods to estimate the degree of reaction of supplementary cementitious materials in blended (or composite) cement pastes. We do not consider explicitly the wider issues of the influence of SCMs on hydration kinetics, nor the measurement of degree of reaction in alkali activated materials. The paper categorises the techniques into direct methods and indirect methods. Direct methods attempt to measure directly the amount of SCM remaining at a certain time, such as selective dissolution, microscopy combined with image analysis, and NMR. Indirect methods infer the amount of SCM reacted by back calculation from some other measured quantity, such as calcium hydroxide consumption. The paper first discusses the different techniques, how they operate and the advantages and limitations along with more details of case studies on different SCMs. In the second part we summarise the most suitable approaches for each SCM, and the paper finishes with conclusions and perspectives for future work.

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Section: Xrdmentioning

confidence: 99%

TC 238-SCM: hydration and microstructure of concrete with SCMs

Scrivener¹,

et al. 2015

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“…Normalized SXRPD patterns were analyzed by using the Rietveld methodology as implemented in the GSAS software package [36], in order to obtain Rietveld Quantitative Phase Analysis (RQPA). Crystal structure descriptions used for all the phases were those included in references [28,29]. However, a revised crystallographic description was used for C 4 A 3 S [34].…”

Section: Sxrpd Data Acquisition and Analysismentioning

confidence: 99%

“…During the last years, several authors have described the quantitative phase analysis of cements, clinkers and supplementary cementitious materials by combining XRPD and Rietveld methodology [24][25][26][27][28], establishing sources of errors and dependence on the results of Rietveld strategies. More recently, this has been expanded to hydrated cementitious systems [3][4][5]13] and in some of them, the non diffracting fraction, also named as Amorphous and Crystalline notquantified, ACn [29], was also calculated [30,31]. Furthermore, the use of an intense X-ray source, such as synchrotron X-rays, coupled with a fast X-ray detector permits time-resolved diffraction experiments allowing in-situ measurements during the hydration process of cements [4,5,13,14,32,33].…”

mentioning

confidence: 99%

In-situ early-age hydration study of sulfobelite cements by synchrotron powder diffraction

Álvarez-Pinazo

Cuesta

García-Maté

et al. 2014

Cement and Concrete Research

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Eco-friendly belite calcium sulfoaluminate (BCSA) cement hydration behavior is not yet well understood. Here, we report an in-situ synchrotron X-ray powder diffraction study for the first hours of hydration of BCSA cements. Rietveld quantitative phase analysis has been used to establish the degree of reaction (α). The hydration of a mixture of ye'elimite and gypsum revealed that ettringite formation (α~70% at 50 h) is limited by ye'elimite dissolution. Two laboratory-prepared BCSA cements were also studied: non-active-BCSA and active-BCSA cements, with β-and α′ H -belite as main phases, respectively. Ye'elimite, in the non-active-BCSA system, dissolves at higher pace (α~25% at 1 h) than in the active-BCSA one (α~10% at 1 h), with differences in the crystallization of ettringite (α~30% and α~5%, respectively). This behavior has strongly affected subsequent belite and ferrite reactivities, yielding stratlingite and other layered phases in non-active-BCSA. The dissolution and crystallization processes are reported and discussed in detail.

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“…This approach quantifies not only amorphous/sub-cooled phases but also misfitting problems of the analyzed crystalline phases and any crystalline phase non-included in the Rietveld control file. Hereafter, this derived value will be called Amorphous and Crystalline not-quantified, ACn [38]. The absolute weight fractions for all crystalline phases are derived using the G-factor approach from their refined phase fractions, and ACn contents are obtained from the difference of the total crystalline phases to 100, knowing the mass attenuation coefficients of the samples [39,40].…”

Section: Lxrpd Data Analysismentioning

confidence: 99%

Hydration studies of calcium sulfoaluminate cements blended with fly ash

García-Maté

Torre

León‐Reina

et al. 2013

Cement and Concrete Research

171

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The main objective of this work is to study the hydration and properties of calcium sulfoaluminate cement pastes blended with fly ash (FA) and the corresponding mortars at different hydration ages. Laboratory X-ray powder diffraction, rheological studies, thermal analysis, porosimetry and compressive strength measurements were performed. The analysis of the diffraction data by Rietveld method allowed quantifying crystalline phases and overall amorphous contents. The studied parameters were: i) FA content, 0, 15 and 30 wt.%; and ii) water addition, water-to-CSA mass ratio (w/CSA = 0.50 and 0.65), and water-to-binder mass ratio (w/b = 0.50). Finally, compressive strengths after 6 months of 0 and 15 wt.% FA [w/CSA = 0.50] mortars were similar: 73 ± 2 and 72 ± 3 MPa, respectively. This is justified by the filler effect of the FA as no strong evidences of reactivity of FA with CSA were observed. These results support the partial substitution of CSA cements with FA with the economic and environmental benefits.

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Rietveld Quantitative Phase Analysis of OPC Clinkers, Cements and Hydration Products

Cited by 141 publications

References 189 publications

TC 238-SCM: hydration and microstructure of concrete with SCMs

TC 238-SCM: hydration and microstructure of concrete with SCMs

In-situ early-age hydration study of sulfobelite cements by synchrotron powder diffraction

Hydration studies of calcium sulfoaluminate cements blended with fly ash

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