Experimental characterization of the constitutive materials composing an old masonry vaulted tunnel of the Paris subway system

A significant proportion of the Paris metro tunnels comprise a masonry vault built out of stone blocks and mortar joints, and sidewalls and slabs made of unreinforced concrete. In order to provide the necessary data for future structural evaluation, an extensive laboratory testing programme has been conducted to characterize the materials of the tunnel separately, i.e., mortar, stone, and concrete. The tests, carried out on specimens taken from cores extracted from a 1930s tunnel, enabled to determine the mechanical properties, including direct tensile, shear strength, and mode I fracture energy, as well as the properties of the stone-mortar interface. Results show that the masonry mortar joints could reach 10 cm in width, and that blocks of stone varied in composition and porosity, thus producing a wide range of mechanical properties. The concrete was composed of large-sized aggregates and showed low stiffness and strength. Based on these experimental results, ratios between mechanical characteristics are hereby proposed. Perspectives on the use of this experimental data in a finite element model are then discussed.     

Le Quartier: Étude Géographique Et Psycho-Sociologique

Les problèmes de la vie sociale en milieu urbain doivent être étudiés non dans un espace géographique au sens étroit, ni dans un espace social indépendent de l'espace géographique mais dans un espace socio-géographique qu'il importe de définir pour chaque agglomération. (P.-H. Chombart de Lauwe, Des hommes et des villes , p. 41)     

Innovations,food storage and the origins of agriculture

Abstract

The global phenomenon of the birth of agriculture remains an enigma and challenges the role of food storage. Much has been written about their invention. A general explanation is needed for its progression in various parts of the world, which is both sociologically based and founded on the archaeological data. This task led Alain Testart to claim that it was by developing their existing skill sets (foraging, pottery, food storage and small-scale agriculture) that nomadic hunter-gatherers, burdened by an increasingly diverse set of tools and equipment, became sedentary. This sedentarism in turn allowed them to specialise in those activities, which had (literally) weighed them down: notably, breeding the first plant cultivars and, often, storing food.     

Sustainable management of metallurgical forest on Mont Lozère (France) during the Early Middle Ages

Mont Lozère, located in the French Massif Central region, provides an exceptional context in which to research the impact that charcoal production and metallurgy had on woodlands, along with the role that these activities played in changing the mountain landscape. This study provides an insight into the land use, forest management methods and metallurgical practices in the area during the Middle Ages (11th to 15th centuries). Medieval charcoal burning platforms, archaeological remains that have often been neglected in the past as a source of historical information, along with nearby smelting sites, were identified, sampled and analysed. In this paper, spatial analyses, radiocarbon dating and anthracological and dendro-anthracological studies have been combined in a unique manner. The results reveal that charcoal burners practiced beech coppicing, where the species and diameter of wood used remained the same over a period of four centuries. It is proposed that this form of metallurgical forest management be considered an early example of a sustainable utilisation of natural resources.     

Scientific Discourse and Local Discourses: The Case of African Archaeology

To the extent that knowledge is the product of a complex construction of Nature-Culture facts more or less perpetuated, the challenge, for archaeology as science discovering and explaining the pasts for developees, is to learn how to manage: (1) its scientific “facts” more or less stabilized or hardened in function of precise, reproducible, universal “buildings of facts,” these facts being combined in networks and allied to specific societal facts, according to a dichotomy between Nature and Culture positioned as incommunicable poles of the world, and (2) traditional, ordinary, daily “facts,” local, contextual“facts” encountered during our activities, publications, lectures, and exchanges with everybody. These facts link approximately or unconsciously Nature and Culture, two poles we moderns have created and separated ontologically. How to produce a legitimate cooperation between these two conflicting discourses during the applications and the improvement of the processes which form, even in the case of archaeology, what is currently termed “development.”Pour l’archéologie en tant que science découvrant et expliquant les passés des peuples en voie de développement, le savoir étant le produit, selon les cultures, de fabrications complexes de faits de Nature-Culture plus ou moins pérennisés, le défi consiste à apprendre à gérer ensemble: (1) ses “faits” scientifiques, plus ou moins stabilisés ou durcis selon des “mises en fait” précises, répétables, universelles, ces faits étant établis en réseau et alliés à tel ou tel secteur de la société en question selon une dichotomie établissant la Nature et la Culture comme pôles incommunicants du monde; et (2) les “faits” de savoirs traditionnels, ordinaires, quotidiens, faits locaux, contextuels rencontrés durant nos activités, publications, cours et échanges avec tout le monde. Ces faits lient approximativement ou inconsciemment la Nature et la Culture, ces deux pôles que nous, modernes, avons créés et ontologiquement séparés. Comment légitimement, même en Archéologie, faire collaborer ces deux discours, en conflit lors des applications et améliorations des processus relevant de qu’on appelle couramment le Développement?     

Les lois de la nature à l'âge classique la question terminologique

Four propositions relative to the laws of nature in the classical period must be noted. 1. Certain regularities in phenomena had been discovered. 2. A concept of law had emerged. 3. Classical science is characterized by the introduction of the notion of the legality of nature. 4. New uses of the word «law» had appeared in scientific texts. This article is devoted to the analysis of only this last proposition, that is to say to a terminological problem. First we will describe the semantic uses of the word «law» that may have contributed to the constitution of its classical meaning: its specific usage, disciplinary usage, usage in physics, in mathematics, in metaphysics. Second we will analyze the various moments of the diffusion of the word in the sciences in the xvii^th century. The general thesis defended in the end is that if the term «law» had indeed been used in science with no reference to a law-giving God prior to the xvii^th century, only this reference, that is, the coming together of its physical and its metaphysical usage, allowed its generalization in the period between the xvii^th and xviii^th centuries.