Publications associées à A long-term study on structural changes in calcium aluminate silicate hydrates

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

Decarbonization potential of steel fibre-reinforced limestone calcined clay cement concrete one-way slabs

Hisham Tarek Mohamed Hafez

This study deals with a comparison of the environmental performance of one-way slabs utilizing steel fibrereinforced limestone calcined clay cement (LC3) concrete with the control case of Ordinary Portland cement concrete. The experimental program constitu ...

Elsevier Sci Ltd2024

CO2 Capture and Management Strategies for Decarbonizing Secondary Aluminium Production

François Maréchal, Daniel Alexander Florez Orrego, Meire Ellen Gorete Ribeiro Domingos, Réginald Germanier

The production of aluminium largely depends on the use of fossil fuels, resulting in the emission of significant amounts of greenhouse gases. As the aluminium industry is working towards decreasing its environmental burdens, the elimination of direct emiss ...

2024

FLO:RE – A new floor system made of reused reinforced concrete and steel elements

Maléna Bastien Masse, Numa Joy Bertola, Célia Marine Küpfer, Corentin Jean Dominique Fivet

Carefully extracting reinforced concrete (RC) elements from soon-to-be demolished structures and reusing them as load-bearing components is an emerging circular low-carbon alternative to building new structures. As floor construction typically accounts for ...

IABSE2024

Additively manufactured steel reinforcement for small scale reinforced concrete modeling: Tensile and bond behavior

Christian Leinenbach, Rafal Wróbel

Small scale (1:30-1:40) Reinforced Concrete is useful for centrifuge testing. However, manufacturing the reinforcing cages by hand at this scale is practically difficult. This paper suggests that small scale reinforcement can be manufactured using a metal ...

Elsevier Sci Ltd2024

Separation of CO2 and TFE by using diethanolamine and diisopropylamine

Elia Mercedes Ruiz Pachon, Muhammad Salman

The near-azeotrope mixture of TFE and CO2 is an important concern urging the scientific community to develop new ways for TFE/CO2 separations. In this work, for the first time, Diisopropylamine (DIPA) and Diethanolamine (DEA) are used as solvents for separ ...

Taylor & Francis Inc2024

Contributions to rebar-to-concrete interaction and its structural implications for design and monitoring applications

Enrique Corres Sojo

Bond between reinforcing bars and concrete has been the focus of extensive research over the last century. This is well-justified as the functioning of reinforced concrete intimately depends on the interaction between rebar and concrete, as for example cra ...

EPFL2024

A concrete answer for circular construction: three prototypes reusing saw-cut elements

Maléna Bastien Masse, Célia Marine Küpfer, Corentin Jean Dominique Fivet

Existing concrete buildings should be retained for as long as possible to reduce the environmental burden of demolition and new construction. However, when urban pressure makes demolition unavoidable, salvaging and reusing concrete elements elsewhere in ne ...

2024

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

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

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

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

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

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

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

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

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

Influence of temperature on phase assemblages of belite-ye'elimite cement

Karen Scrivener, Barbara Lothenbach, Natechanok Chitvoranund, Diana Londoño Zuluaga

This paper studies the effect of temperature on the phase assemblages of belite-ye'elimite cement. A comparison is made between thermodynamic modelling and experimental data at 28 and 180 days of hydration at 5, 20, 40, and 60 degrees C. The fast reaction ...

Pergamon-Elsevier Science Ltd2023

Low-tech methods for the reuse of reinforced concrete structural elements

Maléna Bastien Masse, Julie Rachel Devènes, Corentin Jean Dominique Fivet, Nicole Widmer

Most of existing buildings are made of concrete, new buildings are being built with it and others are demolished when still in good structural condition. This drives increased demands for raw materials, greenhouse gas emissions, and an accumulation of demo ...

2023