Publications associées à Expansion mechanisms in calcium aluminate and sulfoaluminate systems with calcium sulfate

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

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

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

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

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

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

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

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

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

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

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

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

Microfluidic study in a meter-long reactive path reveals how the medium’s structural heterogeneity shapes MICP-induced biocementation

Lyesse Laloui, Dimitrios Terzis, Ariadni Elmaloglou

Microbially induced calcium carbonate (CaCO3) precipitation (MICP) is one of the major sustainable alternatives to the artificial cementation of granular media. MICP consists of injecting the soil with bacterial- and calcium-rich solutions sequentially to ...

Nature Research2022

Nanoscale modelling of ionic transport in the porous C-S-H network

Khalil Ferjaoui

To reduce the CO2 footprint of construction materials, concrete producers blend their cement with Supplementary Cementitious Materials (SCMs). SCMs such as fly ash or blast furnace slag are mostly the byproducts of other industries. And while SCMs are chos ...

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

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

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

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

Atomistic Simulation of Cementitious Systems: An Insight Into Adsorption of Ions and Small Molecules Onto Portlandite and C-S-H Surfaces

Masood Valavi

Calcium-Silicate-Hydrate (C-S-H) has been studied extensively over the last few decades to gain understanding toward the underlying mechanism of different stages during cement hydration. The variable stoichiometry and nanocrystallinity of C-S-H makes it di ...

EPFL2022