Publications related to Deterioration of mortar bars immersed in magnesium containing sulfate solutions

Contradict mechanism of long-term magnesium and sodium sulfate attacks of nano silica-modified cement mortars - Experimental and thermodynamic modeling

The mechanisms of external sulfate attack on cement mortars containing nano silica have been studied under full immersion conditions after 3 years. The sulfate degradation processes were compared between sodium sulfate and magnesium sulfate solutions with ...

Elsevier Sci Ltd2024

Effect of different ions on dissolution rates of silica and feldspars at high pH

Karen Scrivener, Barbara Lothenbach, Mahsa Bagheri, Mahdieh Shakoorioskooie

The dissolution kinetics of silica-containing minerals in aggregates influences strongly the process of ASR in concrete. In this paper, the effect of different ions on the dissolution rates of SiO2 (amorphous and quartz) and feldspars at high pH values was ...

Pergamon-Elsevier Science Ltd2022

Resistance of cementitious materials to sulfate attack: quantifying performance with a reliable unidirectional approach

Qiao Wang

Depending on the environmental conditions, concrete materials can come into contact with sulfate ions which are widely present in rivers, underground water, sewers, seawater and soil. Sulfates can react with the cement paste in concrete and cause damage wh ...

EPFL2022

Strength-promoting mechanism of alkanolamines on limestone-calcined clay cement and the role of sulfate

Karen Scrivener, François Henri Avet, Wilasinee Hanpongpun, Xuerun Li, Hong Huang

This paper reports the strength-promoting mechanism of alkanolamines on limestone-calcined clay cement (LC3). The hydration kinetics, phase formation and microstructure of LC3 with triethanolamine (TEA) or triisopropanolamine (TIPA) were investigated. TEA ...

Pergamon-Elsevier Science Ltd2021

Limestone calcined clay cements (LC3): raw material processing, sulfate balance and hydration kinetics

Franco Alberto Zunino Sommariva

Limestone calcined clay cements (LC3) are blended cements that combine clinker, limestone, calcined clay and gypsum. The availability of the materials required to produce LC3 and the good performance that it achieves, makes LC3 suitable as a sustainable re ...

EPFL2020

Factors influencing the sulfate balance in pure phase C3S/C(3)A systems

Karen Scrivener, Franco Alberto Zunino Sommariva

Understanding the sulfate balance mechanism of cement is needed for an effective use of sustainable blended cements. Pure phase systems allow to study the interaction between sulfate and each of the phases involved in early age hydration separately. This p ...

Pergamon-Elsevier Science Ltd2020

Tuning the Incorporation of Magnesium into Calcite during Its Crystallization from Additive-Free Aqueous Solution

Camelia Borca, Huachuan Du, Esther Amstad

Under ambient conditions, marine organisms are able to synthesize a variety of functional materials, ranging from eye lenses to protective shells through the meticulous control over magnesium incorporation into calcite during its crystallization. The mecha ...

AMER CHEMICAL SOC2019

Magnesium Partitioning Between Earth's Mantle and Core and its Potential to Drive an Early Exsolution Geodynamo

James Badro

Magnesium partitioning between metal and silicate was experimentally investigated between 34 and 138GPa, 3,500 and 5,450K using laser-heated diamond anvil cells. The 22 measurements are combined with previously published data (total of 49 measurements) to ...

AMER GEOPHYSICAL UNION2018

Degradation mechanism of slag blended mortars immersed in sodium sulfate solution

Karen Scrivener, Cheng Yu, Wei Sun

Additions of slag are usually considered to give cementitious materials which perform well in sulfate bearing environments. This paper compares the deterioration of slag cement blends to those of plain Portland cement and demonstrates that this occurs more ...

Pergamon-Elsevier Science Ltd2015

Methane Production from Microalgae via Continuous Catalytic Supercritical Water Gasification: Development of Catalysts and Sulfur Removal Techniques

Gaël Peng

This doctoral thesis aims at demonstrating the technical feasibility of methane production from microalgae via continuous catalytic supercritical water gasification (CSCWG). This work focuses on three different research approaches: (i) assessment and impro ...

EPFL2015

Application of Image Analysis Based on SEM and Chemical Mapping on PC Mortars under Sulfate Attack

Cheng Yu, Wei Sun

The degradation mechanisms of cementitious materials exposed to sulfate solutions have been controversial, despite considerable research. In this paper, two methodologies of image analysis based on scanning electron microscope and chemical mapping are used ...

Journal Wuhan Univ Technology2014

Effect of Magnesium and Zinc Ions on the Hydration Kinetics of C3S

Marco Cantoni, Karen Scrivener, Amélie Bazzoni, Qiao Wang

Impure tricalcium silicate (C3S) in portland cement may contain various foreign ions. These ions can stabilize different polymorphs of C3S at room temperature and may affect its reactivity. In this paper, the effects of magnesium and zinc on the polymorph ...

Wiley-Blackwell2014

Enzyme and Acid Deconjugation of Plasma Sulfated Metanephrines

Sandrine Gerber

Background: Total (i.e. free + sulfated) metanephrines in plasma is a biomarker for the diagnosis of pheochromocytoma/paraganglioma. Sulfated metanephrines must be completely deconjugated by perchloric acid hydrolysis or sulfatase treatment prior to analyt ...

Elsevier2014

Mechanism of expansion of mortars immersed in sodium sulfate solutions

Karen Scrivener, Cheng Yu, Wei Sun

The mechanisms behind the expansion of samples immersed in solutions containing sulfate ions have been controversial. Expansion is believed to originate in the formation of ettringite, but it is not possible to find any direct correlation between these two ...

Pergamon-Elsevier Science Ltd2013

Influence of bicarbonate ions on the deterioration of mortar bars in sulfate solutions

Karen Scrivener, Wolfgang Kunther, Barbara Lothenbach

This work investigates the influence of bicarbonate ions on the deterioration of cementitious material exposed to sulfate ions. Mortars based on a CEM I and on a CEM III/B cement were investigated. Experimental investigations were compared to thermodynamic ...

Pergamon-Elsevier Science Ltd2013

On the relevance of volume increase for the length changes of mortar bars in sulfate solutions

Karen Scrivener, Wolfgang Kunther, Barbara Lothenbach

The ingress of sulfate ions into cementitious materials leads to the formation of ettringite, gypsum and other phases. The increase in solid volume through the formation of these phases is often assumed to be the only reason for expansion. In this paper we ...

Pergamon-Elsevier Science Ltd2013

Dental Phenotype in Jalili Syndrome Due to a c.1312 dupC Homozygous Mutation in the CNNM4 Gene

Jalili syndrome denotes a recessively inherited combination of an eye disease (cone-rod dystrophy) and a dental disorder (amelogenesis imperfecta), which is caused by mutations in the CNNM4 gene. Whereas the ophthalmic consequences of these mutations have ...

Public Library of Science2013

An experimental model approach of biologically-assisted silicate dissolution with olivine and Escherichia coli - Impact on chemical weathering of mafic rocks and atmospheric CO2 drawdown

Philippe Gillet, Bruno Garcia

Chemical weathering of Mg, Ca-silicates and alumino-silicates contributes significantly to the drawdown of atmospheric CO2 over long time scales. The present work focuses on how this mode of weathering may change in the presence of free-living bacteria in ...

Pergamon-Elsevier Science Ltd2013

Investigation of Sulfate Attack by Experimental and Thermodynamic Means

Wolfgang Kunther

This work investigates sulfate attack in complex sulfate environments by exposing different binder types to various sulfate solutions and comparing predicted phase and volume changes with experimental data. The most important aspects of this work can be gr ...

EPFL2012

Limestone Addition in Cement

Olga Agata Chowaniec

Addition of fine limestone provides an excellent means to reduce the amount of clinker in cement. It is now well accepted that limestone partially reacts in cementitious systems with C3A to produce hemi- and monocarboaluminate phases and as a consequence m ...

EPFL2012