Concept

Gypse

Publications associées (24)

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

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

Christian Leinenbach

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

Testing and nonlinear modelling of industrialized light-frame wooden diaphragms including optimized nailing and nonstructural sheathing

Edisson Xavier Estrella Arcos

This article presents the outcomes of a large project towards the investigation of the lateral performance of full-scale industrialized light-frame wooden diaphragms. 10 full-scale diaphragms of 3.6 m by 2.4 m were tested under in-plane lateral loading (mo ...

Elsevier Sci Ltd2023

Sulfur-cycling chemolithoautotrophic microbial community dominates a cold, anoxic, hypersaline Arctic spring

Ianina Altshuler

Background Gypsum Hill Spring, located in Nunavut in the Canadian High Arctic, is a rare example of a cold saline spring arising through thick permafrost. It perennially discharges cold (similar to 7 degrees C), hypersaline (7-8% salinity), anoxic (similar ...

BMC2023

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

An in-situ 3D micro-XRD investigation of water uptake by alkali-silica-reaction (ASR) product

Solène Anne-Lise Albinski

The ASR products in concrete have various chemical compositions. It is yet unclear whether and how these products develop micro-expansion upon moisture ingress. This paper presents a 3D in-situ observation of the crystallography and volume change of an ASR ...

Pergamon-Elsevier Science Ltd2021

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

Spontaneous ecological recovery of vegetation in a red gypsum landfill: Betula pendula dominates after 10 years of inactivity

François Gillet

Red gypsum is the product of the neutralization of titanium dioxide (TiO2) extraction residue from ilmenite and anatase. The disposal of red gypsum creates heterogeneous plots with layers that may include Fe, Ca, Al, Mg, Mn, S, and other elements and an al ...

ELSEVIER SCIENCE BV2019

Limestone reaction in calcium aluminate cement–calcium sulfate systems

Karen Scrivener, Julien Bizzozero

This paper reports a study of ternary blends composed of calcium aluminate cement, calcium sulfate hemihydrate and limestone. Compressive strength tests and hydration kinetics were studied as a function of limestone and calcium sulfate content. The phase e ...

Pergamon-Elsevier Science Ltd2015

Evaluation of geochemical and hydrogeological processes by geochemical modeling in an area affected by evaporite karstification

The Ebro Valley in the outskirts of Zaragoza (NE Spain) is severely affected by evaporite karstification, leading to multiple problems related to subsidence and sinkhole formation. In this work, a combination of inverse (mixing + mass-balance) and forward ...

Elsevier Science Bv2015

Kinetic model for calcium sulfate alpha-hemihydrate produced hydrothermally from gypsum formed by flue gas desulfurization

Xuerun Li

Modeling of the kinetics of the synthesis process for calcium sulfate alpha-hemihydrate from gypsum formed by flue gas desulfurization (FGD) is important to produce high-performance products with minimal costs and production cycles under hydrothermal condi ...

Wiley-Blackwell2015

Degradation mechanism of slag blended mortars immersed in sodium sulfate solution

Wei Sun, Karen Scrivener

Additions of slag are usually considered to give cementitious materials which perform well in sulfate bearing environments. This paper compares the deterioration of slag cement blends to those of plain Portland cement and demonstrates that this occurs more ...

Pergamon-Elsevier Science Ltd2015

Expansion mechanisms in calcium aluminate and sulfoaluminate systems with calcium sulfate

Karen Scrivener, Christophe Gosselin, Julien Bizzozero

The long-term expansion of calcium aluminate cement and calcium sulfoaluminate cement in the presence of added gypsum has been studied for samples cured under water. Progressively higher amounts of gypsum were added to the CAC or CSA and it was found that ...

Pergamon-Elsevier Science Ltd2014

Interactions between alite and C(3)A-gypsum hydrations in model cements

Karen Scrivener, Alexandra Quennoz

This paper focuses on the interactions that occur between cement phases during early hydration, especially between the hydration of alite and C(3)A-gypsum. This study shows that alite reaction is accelerated in the presence of gypsum. This acceleration was ...

Pergamon-Elsevier Science Ltd2013

On the relevance of volume increase for the length changes of mortar bars in sulfate solutions

Karen Scrivener

The ingress of sulfate ions into cementitious materials leads to the formation of ettringite, gypsum and other phases. The increase in solid volume through the formation of these phases is often assumed to be the only reason for expansion. In this paper we ...

Pergamon-Elsevier Science Ltd2013

Hydration of C(3)A-gypsum systems

Karen Scrivener, Alexandra Quennoz

Hydration of C(3)A-gypsum systems with different gypsum additions was investigated in terms of the phase assemblage, kinetics and microstructural development. The second stage of the reaction, which begins after the depletion of gypsum, was of particular i ...

Pergamon-Elsevier Science Ltd2012

Cement substitution by a combination of metakaolin and limestone

Karen Scrivener, John Espen Rossen, Mathieu Antoni

This study investigates the coupled substitution of metakaolin and limestone in Portland cement (PC). The mechanical properties were studied in mortars and the microstructural development in pastes by X-ray diffraction, thermogravimetry analysis, mercury i ...

Pergamon-Elsevier Science Ltd2012

Limestone Addition in Cement

Olga Agata Chowaniec

Addition of fine limestone provides an excellent means to reduce the amount of clinker in cement. It is now well accepted that limestone partially reacts in cementitious systems with C3A to produce hemi- and monocarboaluminate phases and as a consequence m ...

EPFL2012

Modelling Hydration Kinetics of Cementitous Systems

Aditya Kumar

The modeling platform µic has been extended to study the hydration of cement based systems. It is shown that the hydration kinetics of alite can be described through the implementation of two mechanisms: a solution controlled dissolution (SCD) mechanism fo ...

EPFL2012