Portlandite solubility and Ca2+ activity in presence of gluconate and hexitols

التفاصيل البيبلوغرافية
العنوان: Portlandite solubility and Ca2+ activity in presence of gluconate and hexitols
المؤلفون: Bouzouaid, Lina, Lothenbach, Barbara, Fernandez-Martinez, Alejandro, Labbez, Christophe
سنة النشر: 2021
المجموعة: Condensed Matter
Physics (Other)
مصطلحات موضوعية: Physics - Chemical Physics, Condensed Matter - Materials Science
الوصف: The current paper investigates the impact of gluconate, D-sorbitol, D-mannitol and D-galactitol on calcium speciation at high pH values by i) solubility measurements of portlandite (Ca(OH)2) and ii) potentiometric titration measurements of calcium salt solutions. Thermodynamic modeling was used to fit the chemical activities of Ca2+ and OH- ions and thus to determine the strength and kind of the different Ca-organic-hydroxide complexes. The strength of complex formation with Ca decreases in the order gluconate >> sorbitol > mannitol > galactitol, which follows the same order as sorption on portlandite. Heteropolynuclear gluconate complexes with calcium and hydroxide dominate the Ca-speciation in the presence of portlandite, while for sorbitol ternary CaSorbOH+ complexes were dominant under alkaline conditions. We expect that these results will help in better understanding the influence of gluconate and hexitols on the hydration of alite and Portland cement.
Comment: Preprint accepted in Cement and Concrete Research
نوع الوثيقة: Working Paper
DOI: 10.1016/j.cemconres.2021.106563
URL الوصول: http://arxiv.org/abs/2108.02477
رقم الأكسشن: edsarx.2108.02477
قاعدة البيانات: arXiv
الوصف
DOI:10.1016/j.cemconres.2021.106563