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Tanto l’ascesa al monte quanto il viaggio via treno possono assumere nella letteratura contemporanea una valenza purgatoriale. La montagna in particolare riveste un duplice valore: è il luogo dell’affermazione e del perfezionamento del singolo, e insieme apre un passaggio verso la dimensione dell’eternità, dell’essenza. Similmente il viaggio ferroviario – ideale prosecutore del viaggio per mare – costituisce sia uno strumento di esplorazione, sia una via di collegamento con l’oltremondo. Entrambi dunque assommano in sé quelle che Freud chiama pulsione di vita e pulsione di morte, la prima intesa come istanza espansiva, la seconda come ritorno all’unità indifferenziata.

Les superplastifiants sont de plus en plus employés dans la technologie du béton. Cette revue inclut les types, la classification et les emplois des superplastifiants, ainsi que leur action sur les bétons de pâte de ciment, frais et durcis. On a décrit leur emploi dans d'autres types de bétons, y-compris le béton résistance très éleveé, le béton haute teneur en alumine et le béton de laitier de haut-fourneau. On a aussi présentéles aspects de durabilité du béton contenant des superplastifiants et un bref profil des normes de l'Amérique du Nord sur les superplastifiants. Superplasticizers are increasingly being used in concrete technology. The review includes types, classification and uses of superplasticizers and their action on cement paste, fresh and hardened concretes. Their use in other types of concrete, including ultra high strength concrete, high alumina concrete and blast furnace slag concrete, is described. The durability aspects of concrete containing superplasticizers and a brief outline of the North American Standards on superlasticizers are also presented.

This paper aims at showing how Gadamer understood the impossibility of any properly unpolitical stance for philosophy by examining the relation of philosophy and politics in his interpretation of Plato’s Republic . I argue that Gadamer’s rejection of the possibility of the ἄπολις (as presented by Aristotle) was prompted by the thoughts of his friend and interlocutor Leo Strauss on the question of the relation of the theoretical life and political life in Platonic-Aristotelian philosophy. I then turn to Gadamer’s reading of the Republic and focus on three aspects of his interpretation: philosophical education in the context of utopian thinking, the Forms and the Idea of the Good, and philosophical knowledge. Tied together, these three elements convene a picture of philosophy that is by no means above or against politics, but rather exists in a harmonious and mutually influencing relation with the political community. I finally suggest that the interpretive conditions of this harmony are not without consequence on how we conceive of philosophy itself, its nature and its task.

Des études de croissance sous-critique des fissures menées sur la pâte de ciment Portland, la pâte de C3S et les systèmes de verre poreux à différentes températures semblent révéler l'existence, dans la pâte de ciment, d'un processus de corrosion sous contrainte aux extrémités des fissures. Subcritical crack growth studies conducted on Portland cement paste, C3S paste, and porous glass systems at different temperatures indicate that a stress corrosion process is probably operative at crack tips in cement paste.

Almost all concrete used in North America contains at least one type of admixture and admixtures are also used widely in many other countries. There are various types of admixtures such as chemical admixtures, air-entraining admixtures, those based on minerals and specialized types used for specific purposes. The incorporation of admixtures results in beneficial effects to concrete in the fresh and hardened state and also in increased durability.