Publications associées à Insights on the role of alumina content and the filler effect on the sulfate requirement of PC and blended cements

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

System for predicting a prognosis of the neuropsychological and/or neuropsychiatric status in a subject

Olaf Blanke, Fosco Bernasconi

The present invention relates to systems and methods for predicting a prognosis of the neuropsychological and/or neuropsychiatric status in a subject based on reports of Minor Hallucination (MH) events in combination with electrophysiological data of the s ...

2024

Atomic-Level and Surface Structure of Calcium Silicate Hydrate Nanofoils

Paul Bowen, Karen Scrivener, 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

Influence of Low- to Medium-Kaolinite Clay on the Durability of Limestone Calcined Clay Cement (LC3) Concrete

Karen Scrivener, Matea Flegar

The kaolinite content is principally responsible for the durability performance of Limestone Calcined Clay Cement (LC3), which calls into question its global applicability. The clay supply has a significant impact on the LC3 system's reduced carbon footpri ...

MDPI2023

Durability Challenges of Low-Grade Calcined Clay Opposed to High-Volume Fly Ash in General Purpose Concrete

Karen Scrivener, Matea Flegar

With the decrease in availability of common supplementary cementitious materials (SCMs) such as fly ash in Europe, the search for appropriate SCMs should be dealt with locally. A com-bination of abundant low-grade calcined clay and limestone powder has pro ...

AMER SOC TESTING MATERIALS2023

Characterisation and hydration kinetics of beta-C2S synthesised with K2SO4 as dopant

Karen Scrivener, Shashank Bishnoi, Franco Alberto Zunino Sommariva, Sreejith Krishnan

In this study, a protocol for synthesising beta-C2S using K2SO4 as a dopant has been reported. Quantitative X-Ray diffraction was used to characterise synthesised samples. It was observed that it is possible to synthesise beta-C2S with high purity (>96 wt% ...

Pergamon-Elsevier Science Ltd2023

Unidirectional penetration approach for characterizing sulfate attack mechanisms on cement mortars and pastes

Karen Scrivener, Qiao Wang, William Wilson

Degradation of cementitious materials by sulfate ions is commonly classified into chemical and physical sulfate attack. So-called "physical" attack dominates in many field situations, but laboratory testing focuses on "chemical" attack under full-immersion ...

Pergamon-Elsevier Science Ltd2023

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

Going Below 50% Clinker Factor in Limestone Calcined Clay Cements (LC3): A Comparison with Pozzolanic Cements from the South American Market

Karen Scrivener, Franco Alberto Zunino Sommariva

Limestone calcined clays are a promising technology as they offer similar performance to OPC from 7 days onwards, while enabling a reduction of the clinker content of 50%. In some regions of the world like South America, pozzolanic cements (i.e., blended c ...

SPRINGER INTERNATIONAL PUBLISHING AG2023

Does carbon footprint reduction impair mechanical properties and service life of concrete?

Karen Scrivener, Diana Londoño Zuluaga

The aim of this study is to evaluate how much the changes in the concrete mix design, which enable carbon footprint reduction, are impacting mechanical properties and predicted service life of concrete structure. The starting point of this study was concre ...

SPRINGER2023

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

Data-driven optimization tool for the functional, economic, and environmental properties of blended cement concrete using supplementary cementitious materials

Hisham Tarek Mohamed Hafez

The need to produce more sustainable concrete is proving imminent given the rising environmental concerns facing the industry. Blended cement concrete, based on any of the prominent supplementary cementitious materials (SCMs) such as fly ash, ground granul ...

ELSEVIER2023

The effect of paste composition, aggregate mineralogy and temperature on the pore solution composition and the extent of ASR expansion

Karen Scrivener, Barbara Lothenbach, Mahsa Bagheri

The reaction kinetics of the alkali silica reaction depends on the composition of the pore solution. The evolution of the pore solution composition in different cement pastes and concretes was studied. Pastes containing silica fume or metakaolin had the lo ...

SPRINGER2022

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

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

The effect of pore microstructure on strength and chloride ingress in blended cement based on low kaolin clay

Karen Scrivener, Diana Londoño Zuluaga

The objective of this study is to analyse the mechanical and durability properties of a high-performance mortars based on low grade kaolin clay and the effect of electrical conductivity and pore microstructure on the chloride penetration resistance. A tota ...

ELSEVIER2022

Properties and occurrence of clay resources for use as supplementary cementitious materials: a paper of RILEM TC 282-CCL

Adrian Alujas Diaz, Ruben Anton Snellings, Franco Alberto Zunino Sommariva, Alastair Thomas Matthew Marsh

The use of clays as resource of supplementary cementitious materials (SCMs) for a new generation of low-carbon cements and concretes is currently the subject of intense research efforts. To this purpose, a large number of clay resources have been explored, ...

SPRINGER2022

The influence of sulfate addition on hydration kinetics and C-S-H morphology of C3S and C3S/C(3)A systems

Karen Scrivener, Franco Alberto Zunino Sommariva

A comprehensive understanding of hydration kinetics, sulfate requirement and phase assemblage of Portland cement is crucial for further optimization of early-age performance, especially when part of cement is replaced by mineral additions in blended cement ...

Pergamon-Elsevier Science Ltd2022

Oxidation of pyrite (FeS2) and troilite (FeS) impurities in kaolinitic clays after calcination

Karen Scrivener, Franco Alberto Zunino Sommariva

Valorisation of locally available clays for producing blended cements is crucial for a widespread adoption of sustainable binders incorporating these materials. In some places, clays can be intermixed with small amounts of iron sulfides, which could eventu ...

SPRINGER2022

Reactive dicalcium silicate binders: Microstructure and transport properties

Adrian-Alexandru Pîrvan

The calcium silicate hydrates (C-S-H) are without doubt one of the most important hydration products in a hardened cement paste. Giving the complexity of the microstructure that forms by hydration of ordinary Portland cement (OPC) and the more recently use ...

EPFL2022