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You searched for subject:(Alternative SCMs). Showing records 1 – 2 of 2 total matches.

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University of Texas – Austin

1. Seraj, Saamiya. Evaluating natural pozzolans for use as alternative supplementary cementitious materials in concrete.

Degree: Civil, Architectural, and Environmental Engineering, 2014, University of Texas – Austin

Concerns over the future availability of traditional SCM sources, such as fly ash, have left the concrete industry in need of alternative sources of SCMs. The research presented here has evaluated natural pozzolans such as pumice, perlite, vitric ash, zeolites, shale and calcined clay as alternative sources of SCMs. Unlike previous research that has only concentrated on empirically evaluating the performance of natural pozzolans in concrete, the research presented in this dissertation has measured both the performance of the pozzolans in cementitious mixtures as well as their physical and chemical characteristics, to draw meaningful relationships between pozzolan properties and performance. The physical and chemical characteristics of these natural SCMs were measured using techniques like particle size analysis, Brunauer–Emmett–Teller (BET) surface area, scanning electron microscope (SEM) imaging, x-ray fluorescence (XRF), x-ray diffraction (XRD), and thermal gravimetric analysis (TGA). The performance of the pozzolans as alternative SCMs was examined by looking at their effect on mortar strength and mixture workability, as well as by their ability to mitigate expansions from durability problems like alkali silica reaction (ASR) and sulfate attack. The performance of the pozzolans was related back to their physical and chemical characteristics to gain an understanding of the underlying mechanisms of cement and pozzolan interaction, and to draw insights as to why some pozzolans perform better than others in cementitious mixtures. Using this knowledge, some of the under-performing pozzolans were modified to see if changes in their properties could improve performance. Results of the research showed that other than the two coarse zeolites, the rest of the pozzolans tested could be used as Class F fly ash replacements in concrete, with the pumice, perlite, metakaolin and fine zeolite being the best performers in terms of mortar strength and durability. Although the pumice mortar had lower strengths than the control at early ages, results from the performance improvement studies showed that the reactivity of pumice could be enhanced by grinding the pozzolans to a finer particle size distribution. Zeolites were found to negatively affect mixture workability, but calcination of the zeolites helped to improve the workability of zeolite mixtures. Advisors/Committee Members: Juenger, Maria C. G. (advisor), Ferron, Raissa D. (advisor).

Subjects/Keywords: Natural pozzolans; Alternative SCMs; Concrete

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Seraj, S. (2014). Evaluating natural pozzolans for use as alternative supplementary cementitious materials in concrete. (Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/28052

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Seraj, Saamiya. “Evaluating natural pozzolans for use as alternative supplementary cementitious materials in concrete.” 2014. Thesis, University of Texas – Austin. Accessed June 15, 2019. http://hdl.handle.net/2152/28052.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Seraj, Saamiya. “Evaluating natural pozzolans for use as alternative supplementary cementitious materials in concrete.” 2014. Web. 15 Jun 2019.

Vancouver:

Seraj S. Evaluating natural pozzolans for use as alternative supplementary cementitious materials in concrete. [Internet] [Thesis]. University of Texas – Austin; 2014. [cited 2019 Jun 15]. Available from: http://hdl.handle.net/2152/28052.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Seraj S. Evaluating natural pozzolans for use as alternative supplementary cementitious materials in concrete. [Thesis]. University of Texas – Austin; 2014. Available from: http://hdl.handle.net/2152/28052

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Université de Sherbrooke

2. Wilson, William. Chemo-mechanical characterization of microstructure phases in cementitious systems by a novel NI-QEDS technique .

Degree: 2018, Université de Sherbrooke

Face à la finitude des ressources de la terre et de sa capacité d’absorption de la pollution, le développement d’écobétons pour un futur industrialisé durable représente un défi majeur de la science du béton moderne. En raison de sa nature hétérogène complexe, les propriétés macroscopiques du béton dépendent fortement des constituants de sa microstructure (ex. silicates de calcium hydratés [C–S–H], Portlandite, inclusions anhydres, porosité, agrégats, etc.). De plus, la nécessité d’une exploitation rapide et optimale des matériaux cimentaires émergents dans les applications industrielles demande de nos jours une meilleure compréhension de leurs particularités chimico-mécaniques à l’échelle micrométrique. Cette thèse vise à développer une méthode de pointe de couplage de la nanoindentation et de la spectroscopie quantitative aux rayons X à dispersion d'énergie (NI-QEDS), puis à fournir une caractérisation chimico-mécanique originale des phases microstructurales présentes dans les matrices réelles de ciments mélangés. La combinaison d’analyses NI-QEDS statistiques et déterministes a ainsi permis d’élargir la compréhension des systèmes avec ciment Portland et ajouts cimentaires (ACs) conventionnels ou alternatifs. Plus spécifiquement, l’étude des C–(A)–S–H (C–S–H incluant l’aluminium ou non) dans différents systèmes à base de ciments mélangés a montré des compositions différentes pour cet hydrate (variations dans les taux de Ca, Si, Al, S et Mg), mais ses propriétés mécaniques n’ont pas été significativement affectées par l’incorporation des ACs dans des dosages typiques. Les résultats présentés ont aussi démontré le rôle important des autres phases imbriquées dans la matrice de C–(A)–S–H, soit les inclusions anhydres dures (ex. le clinker et les ACs) et les autres hydrates tels que la Portlandite et les hydrates riches en aluminium (ex. les carboaluminates) avec des propriétés mécaniques plus élevées que celles des C–(A)–S–H. La thèse est basée sur cinq articles couvrant : (1) une analyse NI-EDS de systèmes incorporant des volumes élevés de pouzzolanes naturelles; (2) le développement de la méthode NI-QEDS; des analyses statistiques NI-QEDS (3) de systèmes avec cendres volantes et laitier, et (4) d’un système combinant ciment, calcaire et argile calcinée; et (5) une exploration déterministe NI-QEDS de systèmes conventionnels et alternatifs incorporant la poudre de verre, le métakaolin, le laitier ou la cendre volante. Finalement, en plus d’avancer les derniers modèles et méthodes micromécaniques, l’outil développé a fourni une perception chimico-mécanique originale des phases microstructurales et de leur arrangement. Le dévoilement de la signature chimico-mécanique de ces pâtes de ciments mélangés particulièrement complexes offre un savoir unique pour l’ingénierie des bétons de demain. Advisors/Committee Members: Tagnit-Hamou, Arezki (advisor), Sorelli, Luca (advisor).

Subjects/Keywords: Éco-bétons; Ajouts cimentaires (ACs); Liants alternatifs; Silicates de calcium hydratés (C-S-H); Microstructure; EDS quantitatif; Micromécanique; Nanoindentation; Eco-concrete; Supplementary cementitious materials (SCMs); Alternative binders; Calcium-silicate-hydrate (C-S-H); Quantitative EDS; Micromechanics

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wilson, W. (2018). Chemo-mechanical characterization of microstructure phases in cementitious systems by a novel NI-QEDS technique . (Doctoral Dissertation). Université de Sherbrooke. Retrieved from http://hdl.handle.net/11143/11620

Chicago Manual of Style (16th Edition):

Wilson, William. “Chemo-mechanical characterization of microstructure phases in cementitious systems by a novel NI-QEDS technique .” 2018. Doctoral Dissertation, Université de Sherbrooke. Accessed June 15, 2019. http://hdl.handle.net/11143/11620.

MLA Handbook (7th Edition):

Wilson, William. “Chemo-mechanical characterization of microstructure phases in cementitious systems by a novel NI-QEDS technique .” 2018. Web. 15 Jun 2019.

Vancouver:

Wilson W. Chemo-mechanical characterization of microstructure phases in cementitious systems by a novel NI-QEDS technique . [Internet] [Doctoral dissertation]. Université de Sherbrooke; 2018. [cited 2019 Jun 15]. Available from: http://hdl.handle.net/11143/11620.

Council of Science Editors:

Wilson W. Chemo-mechanical characterization of microstructure phases in cementitious systems by a novel NI-QEDS technique . [Doctoral Dissertation]. Université de Sherbrooke; 2018. Available from: http://hdl.handle.net/11143/11620

.