Élites et archives judiciaires : notables lyonnais en conflit (1848-1860)

L'auteur livre les premiers résultats d'une recherche consacrée aux conflits dans lesquels sont impliquées les élites de la France du XIXe siècle, notamment dans la région Centre-Est. Le dépouillement sériel des jugements du tribunal civil de Lyon, de 1848 à 1860, a livré 220 jugements relatifs au patriciat lyonnais, soit 0,68 % de l'activité de la Cour pour à peine 1 % de la population. Les élites ne se distinguent que par une proportion relativement élevée de litiges relatifs à des loyers impayés ou à des créances non honorées. La proportion des procès de succession, elle, n'est pas supérieure à la moyenne. Une étude de cas, enfin, est consacrée à l'affaire qui oppose deux cadets — dont un prêtre — à leurs aînés — dont un chanoine —, tous deux bénéficiaires de préciputs. Du XVIIIe au XIXe siècle, les conflits se sont déplacés au sein de la famille : ils sont internes à la frérèche, et non plus inter-générationnels.The author presents the initial results of a research on the disputes in which the 19th century French elite was involved, in particular in the Centre-Eastern part of France. Going through the sentences of the civil court in Lyons between 1848 and 1860 has revealed 220 cases related to the elite, i.e. 0.68% of the cases for less than 1% of the population. The main distinctive feature of the elite was a relatively high proportion of disputes relating to unpaid rents and debts. The proportion of inheritance cases was not above the average. Last, a case study is dedicated to the dispute between two younger brothers — including a priest — to their elder brothers — one of them a canon — as both the elders benefited from an larger share of the legacy. Between the 18th and the 19th centuries, family conflicts had changed: they no longer opposed generations, but brothers

Effect of cellulose ethers on water retention in freshly-mixed mortars

International audienceCellulose ethers are polymers frequently introduced into mortar formulations in order to improve water retention capacity and workability of the freshly-mixed materials. Physico-chemical parameters of these admixtures (molecular weight, granulometry, substitution degrees, etc) seem to have a strong influence on mortar water retention capacity. In this paper, the influence of cellulose ether molecular weight on mortar water retention and its consistency was studied. Moreover, a new method was used to evaluate mortar consistency, named Consistor Baronnie method. This method was confirmed with rheological measurements

Water transport in freshly-mixed mortars containing cellulose ethers

Groupe de travail n°2 : Interactions éther de cellulose-ciment du CEReM (Consortium d'Etudes et de Recherches sur les Mortiers)Polysaccharides are polymers frequently introduced into mortar formulations in order to improve the workability and water retention capacity of the fresh materials [1]. Among all the polysaccharides, cellulose ethers seem to be the most suitable molecules to obtain a mortar with pretty good water retention ability (i.e. higher than 94%). On the other hand, polysaccharides such as starch ethers or starches generally induce a low increase in water retention (i.e. up to 85%). Mortar consistency may contribute to its water retention capacity but this hypothesis should be checked by further investigations. Indeed, cellulose ethers could induce excellent water retention thanks to the possible superposition of two phenomena [2]: - a rheological effect similar to the one caused by other polysaccharides; - an effect that could be specific to cellulose ethers, which remains to be defined. It could be caused by a modification of the porous network in the fresh state, osmotic pressure or the presence of a cellulose ether film playing the role of diffusion barrier. The molar mass distribution of polysaccharides has been determined by size exclusion chromatography. Using such well-known molecules, it should be possible to understand the functioning of three types of cellulose ethers (HEC, HPMC and HEMC) on mortar water retention. Then, the influence of mortar consistency on water retention has been studied in order to verify if there is a relationship between these two parameters. To complete the panel, the impact of starch ethers on water retention and mortar consistency has also been investigated

NMR investigations of water retention mechanism by cellulose ethers in cement-based materials

International audienceWe show how nuclear magnetic spin-lattice relaxation dispersion of proton-water (NMRD) can be used to elucidate the effect of cellulose ethers on water retention and hydration delay of freshly-mixed white cement pastes. NMRD is useful to determine the surface diffusion coefficient of water, the specific surface area and the hydration kinetics of the cement-based material. In spite of modifications of the solution's viscosity, we show that the cellulosic derivatives do not modify the surface diffusion coefficient of water. Thus, the mobility of water present inside the medium is not affected by the presence of polymer. However, these admixtures modify significantly the surface fraction of mobile water molecules transiently present at solid surfaces. This quantity measured, for the first time, for all admixed cement pastes is thus relevant to explain the water retention mechanism

Influence of Cellulose Ether Particle Size on Water Retention of Freshly-Mixed Mortars

International audienceCellulose ethers are polymers frequently introduced into mortar formulations in order to improve water retention capacity and workability of the freshly-mixed materials. Physico-chemical parameters of these admixtures (molecular weight, granulometry, substitution degrees, etc) seem to have a strong influence on mortar water retention capacity. In this paper, the influence of cellulose ether particle size was studied. Two behaviors were highlighted regarding the particle size effect on mortar water retention. On the one hand, for cellulose ethers providing intermediate water retention, this parameter is fundamental: the thinner the particles, the better the water retention. The increase in water retention was explained by the rate of dissolution of every fraction which was faster for the thinnest particles. On the other hand, for admixtures providing strong water retention, the effect of this parameter was weaker or not relevant. Indeed, a cellulose ether concentration threshold was noticed, justifying this behavior

Cellulose ethers influence on water retention and consistency in cement-based mortars

International audienceCellulose ethers (CE) are commonly used as additives to improve the quality of cement-based materials. As admixtures, they improve the properties of mortars such as water retention, workability, and open time. Also, polysaccharides such as starch derivatives are used to improve the consistency of the fresh material. The properties of cement-based mortars at fresh state were investigated. The effect of CE and their physico-chemical parameters (molecular weight, substitution degrees, etc.) on both water retention and rheological properties of mortars were studied. Moreover, some starch derivatives were also examined in order to better understand the water retention mechanisms. Rheological measurements showed that CE have a thickening effect for a content of 0.27 wt.%. Besides, a fundamental effect of CE molecular weight on mortar consistency and its water retention capability was highlighted. Finally, the comparison with starch ethers proved that, for those admixtures, water retention is not directly linked to mortar's viscosity

Nuclear magnetic relaxation dispersion investigations of water retention mechanism by cellulose ethers in mortars

International audienceWe show how nuclear magnetic spin-lattice relaxation dispersion of proton-water (NMRD) can be used to elucidate the effect of cellulose ethers on water retention and hydration delay of freshly-mixed white cement pastes. NMRD is useful to determine the surface diffusion coefficient of water, the specific area and the hydration kinetics of the cement-based material. In spite of modifications of the solution's viscosity, we show that the cellulosic derivatives do not modify the surface diffusion coefficient of water. Thus, the mobility of water present inside the medium is not affected by the presence of polymer. However, these admixtures modify significantly the surface fraction of mobile water molecules transiently present at solid surfaces. This quantity measured, for the first time, for all admixed cement pastes is thus relevant to explain the water retention mechanism

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

International audienceThe 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