A pulsed field gradient and NMR imaging investigations of the water retention mechanism by cellulose ethers in mortars

Laetitia Patural (1, 2, 3) , Patrice Porion (4) , Henri van Damme (5) , Alexandre Govin (1, 2, 3) , Philippe Grosseau (1, 2, 3) , Bertrand Ruot (6) , Olivier Devès (6)

1 SPIN-ENSMSE - Centre Sciences des Processus Industriels et Naturels
2 P2MC-ENSMSE - Département Poudres et Matériaux Multi-Composants
3 LPMG-EMSE - Laboratoire des Procédés en Milieux Granulaires
4 CRMD - Centre de Recherche sur la Matière Divisée
5 PPMD - Laboratoire de Physico-Chimie des Polymères et des Milieux Dispersés
6 CSTB - Centre Scientifique et Technique du Bâtiment

The study presented in this paper is devoted to improve the knowledge on the influence of cellulose ethers (CE) on the freshly-mixed mortars water retention. Indeed, this crucial property is the most important imparted by these polysaccharides. One of the assumptions proposed to explain this phenomenon is that CE acts as diffusion barrier to the water. To test this hypothesis, the CE effect on the self-diffusion coefficient of water in solution and on the water mobility between two fresh cement pastes was studied by Nuclear Magnetic Resonance. CE does not significantly modify the water self-diffusion coefficient in CE solution or in admixed cement pastes. Moreover the interdiffusion imaging experiments demonstrated that the water diffusion at the paste/paste interface is not affected by the presence of cellulosic admixture.

Mots clés: Cellulose ether; Diffusion coefficient; Freshly-mixed; Mortar (E); Water retention

Domaines: Génie des procédés

Laetitia Patural, Patrice Porion, Henri van Damme, Alexandre Govin, Philippe Grosseau, et al.. A pulsed field gradient and NMR imaging investigations of the water retention mechanism by cellulose ethers in mortars. Cement and Concrete Research, 2010, 40 (9), pp.1378-1385. ⟨10.1016/j.cemconres.2010.04.001⟩. ⟨hal-00542968⟩