HYDRAULIC AND LEACHING BEHAVIOUR OF BELITE CEMENTS PRODUCED WITH ELECTRIC ARC FURNACE STEEL SLAG AS RAW MATERIAL

Three belite-rich cements consisting of a clinker made with 0 (BC), 5 (BC5) and 10 wt. % (BC10) electric arc furnace steel slag (EAFS) as raw material, were studied for their hydraulic and leaching behaviour. Hydration behaviour was studied by FTIR, TG/DTG and SEM analyses. The cements with EAFS resulted in a higher C2S/C3S and C4AF/C3A ratio compared to the reference body. As a result, the rate of hydration was low at early days whereas the structure was porous with scattered AFm and C–S–H crystals. At 28 days, a comparable dense microstructure consisting largely of C–S–H is observed in all mortars. Leaching was studied for V and Cr by means of tank test according to standard NEN 7345. The results showed V release below 2 μg/l. Chromium release calculated per 24 h was 1.4 μg/l in BC5 and 2.4 μg/l in BC10, which is much lower than the parametric value of 50 μg/l specified by the European Directive for drinking water (98/83/EC)

Investigating the Effect of Emoji in Opinion Classification of Uzbek Movie Review Comments

Opinion mining on social media posts has become more and more popular. Users often express their opinion on a topic not only with words but they also use image symbols such as emoticons and emoji. In this paper, we investigate the effect of emoji-based features in opinion classification of Uzbek texts, and more specifically movie review comments from YouTube. Several classification algorithms are tested, and feature ranking is performed to evaluate the discriminative ability of the emoji-based features.Comment: 10 pages, 1 figure, 3 table

Processing and characterisation of standard and doped alite-belite-ye'elimite ecocement pastes and mortars

Supplementary data to this article can be found online at https://doi.org/10.1016/j.cemconres.2019.105911.Cement and Concrete Research 127 (2020) 105911Here, we report the processing optimisation of two laboratory-prepared alite-belite-ye'elimite ecocements (standard and doped) that release to the atmosphere ~13% less CO2 than Portland Cement during fabrication. The processing was optimised through rheological measurements, where homogeneous pastes and mortars were finally prepared through the study and optimisation of both the superplasticiser content and the water-to-cement ratio. Both parameters were correlated with the phase assembly of selected pastes and compressive strength of the corresponding mortars. After optimisation, mortars with high compressive strengths (~72 and ~77 MPa for the standard mortar, and ~41 and ~75 MPa for the doped one, at 7 and 28 days, respectively) were prepared. Furthermore, the important increase in compressive strength from 7 to 28 days of the optimised mortar prepared from the doped ecocement is due to its composition (the higher content of belite jointly with the reaction of its active polymorph (α'H-belite)).This work is part of the PhD of Mr. Jesus D. Zea-Garcia. This research has been supported by Spanish MINECO and FEDER [BIA2017- 82391-R research project and I3 (IEDI-2016-0079) program]

Synthesis, characterization and properties of calcium ferroaluminate belite cements produced with electric arc furnace steel slag as raw material

This study investigated the use of 10 (M1), 17 (M2) and 27 wt.% (M3) electric arc furnace steel slag (EAFS) as a raw material in the production of calcium ferroaluminate belite cement clinker, after firing at 1320 C. The thermal behavior of the raw meals was studied by TG/DSC and XRD whereas for the analysis of the clinkers, XRD/QXRD, SEM/EDS and EPMA were employed. The resulting clinker was co-grinded with 5 and 20 wt.% Flue Gas Desulfurization (FGD) gypsum and the properties were determined by a series of tests in accordance to EN standards. The evolution of hydration was investigated by SEM and the development of compressive strength. The results revealed that the formed phases in the clinkers were C2S, C4AF and C 4A3Ŝ. The main hydration products were ettringite, AFm and hydrogarnet. The leached CrVI was below 1 ppm in M3. Compressive strength in cements with 5 wt.% FGD gypsum was (in MPa): 18.3 for M1, 14.3 for M2 and 7.8 for M3 at 28 days, whereas for 20 wt.% FGD gypsum, the values were almost doubled.© 2013 Elsevier Ltd. All rights reserved.publisher: Elsevier articletitle: Synthesis, characterization and properties of calcium ferroaluminate belite cements produced with electric arc furnace steel slag as raw material journaltitle: Cement and Concrete Composites articlelink: http://dx.doi.org/10.1016/j.cemconcomp.2013.08.002 content_type: article copyright: Copyright © 2013 Elsevier Ltd. All rights reserved.status: publishe

Valorization of Electric Arc Furnace Steel Slag as raw material in the production of low energy FA- belite cement

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Utilization of EAF metallurgical slag in “green” belite cement

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Investigating the Effect of Emoji in Opinion Classification of Uzbek Movie Review Comments

Opinion mining on social media posts has become more and more popular. Users often express their opinion on a topic not only with words but they also use image symbols such as emoticons and emoji. In this paper, we investigate the effect of emoji-based features in opinion classification of Uzbek texts, and more specifically movie review comments from YouTube. Several classification algorithms are tested, and feature ranking is performed to evaluate the discriminative ability of the emoji-based features