Emmanuel Gallucci

TL;DR: In this paper, the influence of the presence of limestone on the hydration of Portland cement was investigated, and it was shown that the stabilisation of monocarbonate in the absence of limestone indirectly stabilised ettringite, leading to a corresponding increase of the total volume of the hydrate phase and a decrease of porosity.

TL;DR: In this article, an extension of this technique to a pilot study of the hydration of a typical Portland cement was described. But the results were compared with independent measures of the same materials by the analysis of backscattered electron images (BSE/IA) and thermogravimetric analysis.

TL;DR: The early hydration of alite has been a subject of controversy for many decades and several theories have been proposed, principally the formation of a protective phase inhibiting dissolution or delayed nucleation and growth, but none have successfully taken into account all the experimental data available as discussed by the authors.

TL;DR: In this paper, the modifications to C-S-H induced by isothermal curing between 5 and 60 degrees C were studied and it was shown that the microstructure of the cement paste is much coarser and porous, which explains the lower final strength obtained by curing at elevated temperatures.

TL;DR: In this paper, three dimensional imaging of capillary porosity allowed the connectivity and tortuosity of the pore network to be studied, and it was shown that the degree of connectivity of the porosity is sensitive to both the spatial resolution of the images and the evolution of contrast resolution during ageing of the cement.

TL;DR: In this article, a new analysis tool was developed to quantify the experimentally observed changes in morphology of portlandite, allowing the calculation of the relative surface energies of the crystal facets.

TL;DR: The use of silica-rich SCMs influences the amount and kind of hydrates formed and thus the volume, the porosity and finally the durability of these materials.

TL;DR: The current state of knowledge of cement hydration mechanisms is reviewed, including the origin of the period of slow reaction in alite and cement, the nature of the acceleration period, the role of calcium sulfate in modifying the reaction rate of tricalcium aluminate, the interactions of silicates and aluminates, and the kinetics of the deceleration period as mentioned in this paper.

TL;DR: The main conclusions of an analysis of low-CO2, eco-efficient cement-based materials, carried out by a multi-stakeholder working group initiated by the United Nations Environment Program Sustainable Building and Climate Initiative (UNEP-SBCI) are presented, based on the white papers published in this special issue as discussed by the authors.

TL;DR: In this article, the effect of minor additions of limestone powder on the properties of fly ash blended cements was investigated using isothermal calorimetry, thermogravimetry (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques, and pore solution analysis.