Publications de Barbara Lothenbach

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

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

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

Christian Ludwig, Barbara Lothenbach, Sonya Barzgar, Yu Yan, Mohamed Tarik

Production of blended cements in which Portland cement is combined with supplementary cementitious materials (SCM) is an effective strategy for reducing the CO2 emissions during cement manufacturing and achieving sustainable concrete production. However, t ...

SPRINGER2022

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

Al uptake in calcium silicate hydrate and the effect of alkali hydroxide

Karen Scrivener, Barbara Lothenbach, Yan Yan

The effect of Al and of pH on the structure of calcium silicate hydrate (C-S-H), the most important hydration product in Portland and blended cement, was studied at Ca/Si similar to 1.0. The presence of Al led to higher amounts of secondary phases, larger ...

Pergamon-Elsevier Science Ltd2022

Effect of alkali hydroxide on calcium silicate hydrate (C-S-H)

Karen Scrivener, Barbara Lothenbach, Yu Yan, Émilie Michèle L'Hôpital, Sheng-Yu Yang

This paper investigates the effect of KOH and NaOH on C-S-H structure and solubility. Both KOH and NaOH have a similar effect, they increase pH values and silicon concentrations, and decrease calcium concentrations. At higher alkali hydroxide concentration ...

Pergamon-Elsevier Science Ltd2022

Predicting damage in aggregates due to the volume increase of the alkali-silica reaction products

Jean-François Molinari, Barbara Lothenbach, Emil Gallyamov

Volume increase between the reactants and the products of alkali silica reaction could reach up to 100%. Taking place inside the aggregates, ASR imposes internal pressure on the surrounding material. In the current paper, we study the possibility of crack ...

Pergamon-Elsevier Science Ltd2022

Understanding the carbonation of concrete with supplementary cementitious materials: a critical review by RILEM TC 281-CCC (vol 53, 136, 2020)

Karen Scrivener, Barbara Lothenbach

A correction to this paper has been published: https://doi.org/10.1617/s11527-020-01558-w ...

SPRINGER2021

The effect of equilibration time on Al uptake in C-S-H

Christian Ludwig, Barbara Lothenbach, Sonya Barzgar, Mohamed Tarik

Pergamon-Elsevier Science Ltd2021

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