@proceedings {99, title = {Modelling cement at fundamental scales: From atoms to engineering strength and durability}, journal = {Euro-C Conference}, volume = {COMPUTATIONAL MODELLING OF CONCRETE STRUCTURES, VOL 1}, year = {2014}, month = {2014}, pages = {139-148}, publisher = {CRC Press-Taylor \& Francis Group}, address = {MAR 24-27, 2014, St Anton am Alberg, AUSTRIA}, abstract = {

The mechanics and rheology of cement pastes are largely determined by the Calcium-Silicate-Hydrate (C-S-H) gel, which is normally the main binding phase. The C-S-H gel is an amorphous material with a nanoscale pore network. Here we consider a model structure of the gel, where a continuous molecular model of non-porous C-S-H is combined with a colloidal model that incorporates the porosity of the gel. Numerical simulations predict mechanical properties and microscopic processes associated with yielding under shear. The proposed model can now be used to extract further properties and to contribute to a broader effort aimed at describing and engineering the multi-scale structure and mechanical behaviour of the cement paste. We finally discuss the opportunities offered by our model with respect to the scientific and technological challenges of modelling and controlling ageing and creep over long time scales.

}, isbn = {978-1-138-02641-4; 978-1-315-76203-6}, doi = {10.1201/b16645-16}, author = {Enrico Masoero and Hamlin M. Jennings and Franz-Josef Ulm and Emanuela Del Gado and Hegoi Manzano and Roland Jean-Marc Pellenq and Sidney Yip}, editor = {Bicanic, N and Mang, H and Meschke, G and DeBorst, R} } @conference {36, title = {Water Isotherms, Shrinkage and Creep of Cement Paste: Hypotheses, Models and Experiments}, booktitle = {Mechanics and Physics of Creep, Shrinkage, and Durability of Concrete: A Tribute to Zdenek P. Ba{\.z}ant}, year = {2013}, month = {Sep-25-2013}, publisher = {ASCE Publications}, organization = {ASCE Publications}, abstract = {

Cement paste has a complex mesoscale structure, and small changes in its pore network potentially cause large variation in measurements such as the water isotherm (also nitrogen). We deconvolute the water isotherm with the help of advanced computational techniques, hypotheses, and a re-examination of published data. The pore system is divided into four different categories, each containing water with its own physical properties. By viewing the highly interdependent roles of water in each of the pore categories as a system, new insights are gained regarding possible mechanisms that control drying, shrinkage, and creep, and experimental strategies for verification.

}, doi = {10.1061/9780784413111.015}, author = {Hamlin M. Jennings and Enrico Masoero and Pinson, Matthew B and Strekalova, Elena G and Patrick A Bonnaud and Hegoi Manzano and Qing Ji and Jeffrey J. Thomas and Roland Jean-Marc Pellenq and Franz-Josef Ulm and others} } @article {53, title = {Set in stone? A perspective on the concrete sustainability challenge}, journal = {MRS bulletin}, volume = {37}, year = {2012}, month = {Apr-09-2012}, pages = {395{\textendash}402}, abstract = {

As the most abundant engineered material on Earth, concrete is essential to the physical infrastructure of all modern societies. There are no known materials that can replace concrete in terms of cost and availability. There are, however, environmental concerns, including the significant CO2 emissions associated with cement production, which create new incentives for university\–industry collaboration to address concrete sustainability. Herein, we examine one aspect of this challenge\—the translation of scientific understanding at the microscale into industrial innovation at the macroscale\—by seeking improvements in cement-paste processing, performance, and sustainability through control of the mechanisms that govern microstructure development. Specifically, we consider modeling, simulation, and experimental advances in fracture, dissolution, precipitation, and hydration of cement paste precursors, as well as properties of the hardened cement paste within concrete. The aim of such studies is to optimize the chemical reactivity, mechanical performance, and other physical properties of cement paste to enable more sustainable processing routes for this ubiquitous material.

}, doi = {10.1557/mrs.2012.55}, author = {Krystyn J. Van Vliet and Roland Jean-Marc Pellenq and Markus J Buehler and Jeffrey C Grossman and Hamlin M. Jennings and Franz-Josef Ulm and Sidney Yip} }