scholarly journals Geopolymer, Calcium Aluminate, and Portland Cement-Based Mortars: Comparing Degradation Using Acetic Acid

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3115 ◽  
Author(s):  
Neven Ukrainczyk ◽  
Murugan Muthu ◽  
Oliver Vogt ◽  
Eddie Koenders
Keyword(s):  
Acetic Acid ◽  
Portland Cement ◽  
Mass Loss ◽  
Calcium Aluminate ◽  
Acid Resistance ◽  
Test Methods ◽  
Core Material ◽  
Microstructural Alterations ◽  
Binder Type ◽  
Potential Alternative

In this paper, we comparitvley studied acetic acid attacks on geopolymer (GP-M), calcium aluminate (CAC-M), and Portland cement (PC-M)-based mortars. Consequent formations of deteriorated or transition layers surrounding the unaltered core material was classified in these three mortars, according to different degradation levels depending on what binder type was involved. Apart from mass loss, hardness, and deterioration depth, their microstructural alterations were analyzed using test methods such as scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), mercury intrusion porosimetry (MIP), powder X-ray diffraction (XRD), and thermogravimetric analysis-differential scanning calorimeter (TGA-DSC), which showed the different mechanisms for each binder type. Elemental maps revealed the decalcification (PC-M and CAC-M) and depolymerization (GP-M) that occurred across the mortar sections. The mass loss, hardness, and porosity were the least affected for GP-M, followed by CAC-M. These results points out that geopolymer-based mortars have improved acid resistance, which can be used as a potential alternative to conventional cement concretes that have been exposed to agro-industrial environments.

Quick Setting Property and Hydration of Portland Cement with Accelerating Agent Based on Calcium Aluminate.

2000 ◽  
Vol 49 (2) ◽  
pp. 209-214
Author(s):  
Minoru TAKEHIRO ◽  
Seishi GOTO ◽  
Koji IOKU ◽  
Hirotaka FUJIMORI
Keyword(s):  
Portland Cement ◽  
Calcium Aluminate ◽  
Agent Based

scholarly journals The dual role of candida glabrata drug:H+ antiporter CgAqr1 (ORF CAGL0J09944g) in antifungal drug and acetic acid resistance

2013 ◽  
Vol 4 ◽  
Author(s):  
Catarina Costa ◽  
André Henriques ◽  
Carla Pires ◽  
Joana Nunes ◽  
Michiyo Ohno ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Candida Glabrata ◽  
Acid Resistance ◽  
Dual Role ◽  
Antifungal Drug ◽  
Acetic Acid Resistance

Mode of Action of Fluoride: Application of New Techniques and Test Methods to the Examination of the Mechanism of Action of Topical Fluoride

1994 ◽  
Vol 8 (2) ◽  
pp. 166-174 ◽  
Author(s):  
D.J. White ◽  
D.G.A. Nelson ◽  
R.V. Faller
Keyword(s):  
Acid Resistance ◽  
Test Methods ◽  
Magic Angle Spinning ◽  
Treatment Modalities ◽  
Magic Angle ◽  
Reaction Products ◽  
In Situ Experiments ◽  
Ph Cycling

Modern techniques in dental research continue to assist in the study of the mode of (anticaries) action of topical fluorides. The Plaque Glycolysis and Regrowth Model (PGRM) facilitates the standardized assessments of antimicrobial effects on plaque following use of test formulations in vivo without complications arising from coincident mineral reactivity. In vivo plaque glycolysis testing demonstrates that topically applied fluoride, at conventional levels found in dentifrices, has only modest effects on the metabolic (acid-producing) activity of dental plaque. Any 'plaque' contribution to fluoride efficacy must come from more subtle effects on plaque acidogenicity than those measured in PGRM. The 19-F MAS NMR (Magic Angle Spinning Nuclear Magnetic Resonance) technique provides unambiguous measures of the reaction products of F-enamel interactions. Studies have revealed a new 'reaction product' of fluoride-enamel interactions-designated as Non-Specifically-Adsorbed Fluoride, NSAF. This species, along with FAP (fluoroapatite), FHAP (fluorohydroxyapatite), and CaF2 (calcium fluoride), contributes to the remineralization/ demineralization benefits of fluoride. pH cycling and in situ denture chip studies permit quantitative assessments to be made of the relative benefits of fluoride in promoting remineralization and in inhibiting demineralization. Results from pH cycling/ in situ experiments are strongly supportive of Koulourides' 'Acquired Acid Resistance' concept, describing fluoride's decay-preventive effects. The continued application of new analytical/physical techniques and testing regimens to the study of fluoride anticaries mechanisms may lead to the development of improved fluoride agents/treatment modalities for the prevention of dental caries.

scholarly journals Calorimetry in the studies of by-pass cement kiln dust as an additive to the calcium aluminate cement

2019 ◽  
Vol 138 (6) ◽  
pp. 4561-4569 ◽  
Author(s):  
Wiesława Nocuń-Wczelik ◽  
Katarzyna Stolarska
Keyword(s):  
Portland Cement ◽  
Rheological Properties ◽  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Cement Kiln ◽  
Phase Assemblage ◽  
Chemical Shrinkage ◽  
High Calcium ◽  
Kinetics Of ◽  
Aluminate Cement

Abstract The studies focused on the kinetics of early hydration in the high-calcium aluminate cement (CAC 70)—by-pass cement kiln dusts (BPCKD)—mixtures. For this purpose, the mixtures of cement with this additive or with some potential constituents of dusts were produced. The microcalorimeter was applied to follow the kinetics of hydration. The investigations with the aim of finding the relationship between the components of initial mixtures and the modification of hydration process were carried out. The rheological properties were characterized, and the chemical shrinkage characteristics were produced. The phase assemblage characterization and microscopic observations were done as well. In case of the high-calcium aluminate-based binders, the modification of setting process was observed; the rheological properties and chemical shrinkage were affected too. The acceleration of heat evolution—the shortening of so-called induction period in the presence of BPCKD additive—was observed. The results were compared to those obtained for the CAC with ordinary Portland cement additive. The results of calorimetric measurements are discussed in terms of the chemical and phase assemblage of this additive as compared to the Portland cement clinker precursors and potassium chloride—the solid and liquid components of the dust.

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