Chalk

Water weakening and the compressive brittle strength of carbonates: Influence of fracture toughness and static friction

Marie Estelle Solange Violay, Corentin Jean-Marie Rémi Noël, Barnaby Padraig Fryer

Water is ubiquitous within the pore space of rocks and has been shown to affect their physical and mechanical behaviour. Indeed, water can act on the rock strength via mechanical (i.e., reducing the effective stresses) or chemical effects (e.g., mineral di ...

2024

The impact of calcite impurities in clays containing kaolinite on their reactivity in cement after calcination

Karen Scrivener, Franco Alberto Zunino Sommariva, Emmanuelle Anne Boehm Courjault

The use of supplementary cementitious materials as a partial replacement for Portland cement is the most effective way to reduce the carbon footprint of the concrete industry. Raw clays containing kaolinite (kaolin) are promising substitute materials. In t ...

SPRINGER2020

The modern analogue of a Cretaceous coral with a calcitic skeleton

Anders Meibom, Jaroslaw Hubert Stolarski

It was argued that, in contrast to all known modern scleractinian corals that form aragonite skeletons, the original mineralogy of the Cretaceous "Coelosmilia" (ca. 70-65 Ma) was calcite during a period when the Mg2+/Ca2+ ratio of the seawater was presumab ...

2019

Assessing the Effect of Calcite Impurities in Clay on Optimal Dehydroxylation Parameters for Enhanced Reactivity

Karen Scrivener, Franco Alberto Zunino Sommariva

This study focused on understanding the influence of different amounts of calcite impurities (0 to 10% by mass) on the optimal parameters for clay dehydroxylation and the reactivity of the final calcined clay. A surface response experimental design was use ...

SPRINGER2018

Aragonitic scleractinian corals in the Cretaceous calcitic sea

Anders Meibom, Stéphane Laurent Escrig, Jaroslaw Hubert Stolarski

Changes in seawater chemistry have affected the evolution of calcifying marine organisms, including their skeletal polymorph (calcite versus aragonite), which is believed to have been strongly influenced by the Mg/Ca ratio at the time these animals first e ...

Geological Soc Amer, Inc2016

Direct Visualization of Single Ions in the Stern Layer of Calcite

Jean-François Molinari, Francesco Stellacci, Kislon Voitchovsky, Peter Spijker, Maria Ricci

Calcite is among the most abundant minerals on earth and plays a central role in many environmental and geochemical processes. Here we used amplitude modulation atomic force microscopy (AFM) operated in a particular regime to visualize single ions close to ...

American Chemical Society2013

Crystallisation of calcium hydroxide in early age model and ordinary cementitious systems

Karen Scrivener

The distribution and morphology of CH particles in various cementitious systems was investigated to determine which parameters influence their nucleation and growth. Morphological image analysis of SEM-BSE images of polished cross-sections was used to meas ...

Pergamon-Elsevier Science Ltd2007