FAITS MARQUANTS (HIGHLIGHTS)

Alliance Métaux de l'invention aux marchés

LCMCP - 15 janvier 2020

Création d’une nouvelle structure de Recherche, Développement et de Valorisation regroupant Sorbonne Université à travers le Laboratoire de Chimie de la Matière Condensée de Paris et 3 PME-ETI : SEQENS, FLUOROTECHNIQUE et EXPIRIS ainsi que ses affiliés SATYS et Gaches Chimie.

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Durability of cement pastes exposed to external sulfate attack and leaching : Physical and chemical aspects

 PPMD Espci - 15 janvier 2020

The unfortunate recent collapse of the Morandi bridge in Genoa has reminded us of the importance of the degradation of concrete and cement with time. For example, cement is attacked by sulfate ions in seawater or underground, leading to expansion, strength loss and eventually the catastrophic loss of structures such as bridges. Cement expansion is usually related to ettringite and gypsum precipitation. However, despite numerous studies and expertise, the exact degradation mechanisms remain unclear and controversial. We have thus conducted a study of this mechanism in collaboration with a private company, Bouygues, and an academic partner, IFSTTAR. It aimed to characterize the possible altered zone and to identify the mechanisms of degradation under sulfate attack. The analysis of the physical and chemical aspects of this phenomenon shows that two modes of transfer occur : transfer of sulfate ions to the cement matrix and leaching of calcium ions to the external solution. The analysis of the chemical composition of the affected material highlights the progressive consumption of portlandite at the surface, the decalcification of C-S-H and the formation of AFt from both Afm and aluminum incorporated in C-S-H.

If you want to know more
O. OmikrineMetalssi, F. Barberon, J.-M. Torrenti, N. Roussel, L. Divet, J.-B. d’Espinose de Lacaillerie, Durability of cement pastes exposed to external sulfate attack and leaching : Physical and chemical aspects, Cement and Concrete Research, 116, pages 134-145 (2019)

https://doi.org/10.1016/j.cemconres.2018.11.006

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Un laboratoire sur puce pour la détection de traces de biomarqueurs

par Emilie Secret - 21 octobre 2019

Les travaux des chercheurs de PHENIX, en collaboration avec le C2N et l’UTCBS, portant sur l’élaboration d’un dispositif, conçu pour la détection rapide de biomarqueurs présents dans les liquides biologiques, mis en avant dans la lettre innovation du CNRS.

Voir en ligne : Voir la lettre innovation