Publications associées à Sulfate de calcium

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

Atomistic modeling of C-S-H: bulk and surface

Ziga Casar

By replacing part of Portland cement with so-called supplementary cementitious materials (SCMs) it is possible to reduce the CO2 footprint of the cement industry. These SCMs are commonly limestone, calcined clay, slag and fly ash. While doing so the early ...

EPFL2023

Atomic-Level and Surface Structure of Calcium Silicate Hydrate Nanofoils

Karen Scrivener, Paul Bowen, Aslam Kunhi Mohamed, Ziga Casar

Deciphering the calcium silicate hydrate (C-S-H) surface is crucial for unraveling the mechanisms of cement hydration and property development. Experimental observations of C-S-H in cement systems suggest a surface termination which is fundamentally differ ...

AMER CHEMICAL SOC2023

The role of Zn in C-S-H atomic structure, nucleation and growth

Anna Morales Melgares

The most promising solution towards cementitious materials with a lower carbon footprint is the partial substitution of the clinker by supplementary cementitious materials (SCMs) such as fly ash, blast furnace slag, limestone and calcined clays. The produc ...

EPFL2023

Hydration and mixture design of calcined clay blended cements: review by the RILEM TC 282-CCL

Karen Scrivener, Franco Alberto Zunino Sommariva, Mohsen Ben Haha, François Henri Avet, Anuj Parashar, Yuvaraj Dhandapani, Sreejith Krishnan

The RILEM technical committee 282-CCL: Calcined Clays as Supplementary Cementitious Materials, investigates all the aspects related to calcined clays, from clay exploration and characterization to calcination process, hydration reactions and concrete prope ...

SPRINGER2022

Active lithoautotrophic and methane-oxidizing microbial community in an anoxic, sub-zero, and hypersaline High Arctic spring

Ianina Altshuler

Lost Hammer Spring, located in the High Arctic of Nunavut, Canada, is one of the coldest and saltiest terrestrial springs discovered to date. It perennially discharges anoxic (

2022

Hydration and durability of fast hardening binders incorporating supplementary cementitious materials

Sarra El Housseini

The use of supplementary cementitious materials (SCMs) is widely considered the most promis-ing approach to reduce CO2 emissions relative to cement production. SCMs are not commonly present in binders used for special applications. On the other hand, due t ...

EPFL2022

Effect of alkali, aluminium and equilibration time on calcium-silicate-hydrates

Yu Yan

Calcium silicate hydrate (C-S-H) is the main hydration product in Portland and blended cements, and greatly affects durability and mechanical properties of the hydrated cement. In the presence of Al-rich supplementary cementitious materials (SCMs), C-(A-)S ...

EPFL2022

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

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

The effect of alkali hydroxides and equilibration time on Al uptake by calcium silicate hydrates (C-S-H)

Sonya Barzgar

Cement production accounts for approximately 8% of man-made CO2 emissions. Lowering these CO2 emissions is currently one of the most important and urgent research topics within the cement community. To reduce these emissions, the Portland cement (PC) is pa ...

EPFL2021

Towards tailored cement-based materials with ground calcium carbonates

Emmanuel Denarié, Lionel Sofia

Proportioning the dosage of Ground Calcium Carbonates (GCC) in cementitious materials, beyond current normative levels, is one of the most promising ways towards sustainability of mortar and concrete technology. Performance parameters such as the water/bin ...

2021

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

Catechol Containing Polyelectrolyte Complex Nanoparticles as Local Drug Delivery System for Bortezomib at Bone Substitute Materials

Martin Guillermo Mueller, Jeremy Pak Hei Wong

The proteasome inhibitor bortezomib (BZM) is one of the most potent anti-cancer drugs in the therapy of multiple myeloma. In this study, an adhesive drug delivery system (DDS) for BZM was developed. Therefore, we extended the present DDS concept of polyele ...

2020

The Influence of some calcined clays from Nigeria as clinker substitute in cementitious systems

Karen Scrivener, François Henri Avet, Akindehinde Ayotunde Akindahunsi

This paper examines the possibility of the use of some clays calcined from Nigeria as partial substitutes for clinker in the production of Limestone Calcined Clay Cement (LC3). The clays were calcined in the oven at a temperature of 800 degrees C and for o ...

2020

The effect of sodium hydroxide on Al uptake by calcium silicate hydrates (C S H)

Christian Ludwig, Barbara Lothenbach, Sonya Barzgar, Mohamed Tarik, Alessio Di Giacomo

To reduce the CO2 emissions from cement production, Portland cement (PC) is partially replaced by supplementary cementitious materials (SCM). Reactions of SCM with PC during hydration leads to the formation of CSH with more silicon and aluminum than in PC, ...

2020

Impacting factors and properties of limestone calcined clay cements (LC3)

Karen Scrivener, Franco Alberto Zunino Sommariva, François Henri Avet, Julien Ston, Aurélie Rosine Favier, Hamed Maraghechi, Wilasinee Hanpongpun

This paper details the main factors influencing the performance of limestone calcined clay cements (LC3). The kaolinite content plays a major role in the rheological properties as well as strength development. Even in the presence of secondary phases, kaol ...

ICE PUBLISHING2019

The influence of the filler effect on the sulfate requirement of blended cements

Karen Scrivener, Franco Alberto Zunino Sommariva

In some blended cements, the optimum amount of sulfate addition differs from that observed in OPC. This study aims to understand the mechanism behind the impact of two SCMs, namely metakaolin and limestone, on the sulfate balance of blended cements. No sig ...

Pergamon-Elsevier Science Ltd2019

Chemical shrinkage of ye'elimite with and without gypsum addition

Karen Scrivener, Mohsen Ben Haha, Frank Bullerjahn

Ye'elimite (Ca4Al6O12SO4 or C(4)A(3)S) is the main hydraulic mineral present in calcium sulphoaluminate cement (CSA). Its reaction is responsible for the (early) hydration and associated cement properties such as the chemical shrinkage. This paper discusse ...

ELSEVIER SCI LTD2019

Rapid evaluation of bioactive Ti-based surfaces using an in vitro titration method

Paul Bowen, Jacques Lemaître, Weitian Zhao

The prediction of implant behavior in vivo by the use of easy-to-perform in vitro methods is of great interest in biomaterials research. Simulated body fluids (SBFs) have been proposed and widely used to evaluate the bone-bonding ability of implant materia ...

Springer2019

Characterisation and hydration of ye'elimite containing cements

Frank Bullerjahn

Calcium sulphoaluminate cements (CSA) with the main phase yeâ elimite are a promising class of non-Portland cements which are gaining increasing interest from the cement industry. However, the hydration kinetics of CSA cements varies strongly, even for ce ...

EPFL2018