Exceptionnalisme américain | EPFL Graph Search

American exceptionalism is the belief that the United States is either distinctive, unique, or exemplary compared to other nations. Proponents argue that the values, political system, and historical development of the U.S. are unique in human history, often with the implication that it is both destined and entitled to play a distinct and positive role on the world stage. It originates in the observations and writings of French political scientist and historian Alexis de Tocqueville, most notably in his comparison of the United States with Great Britain and his native France. Tocqueville was the first writer to describe the country as "exceptional" following his travels there in 1831. The earliest documented use of the specific term "American exceptionalism" is by American communists in intra-communist disputes in the late 1920s. Political scientist Seymour Martin Lipset argues that the United States is exceptional in that it started from a revolutionary event. He therefore traces the origins of American exceptionalism to the American Revolution, from which the U.S. emerged as "the first new nation" with a distinct ideology and having a unique mission to transform the world. This ideology, which Lipset called Americanism, but is often also referred to as American exceptionalism, is based on liberty, egalitarianism, individualism, republicanism, democracy, and laissez-faire economics; these principles are sometimes collectively referred to as "American exceptionalism". As a term in social science, American exceptionalism refers to the United States' status as a global outlier. Critics of the concept claim that the idea of American exceptionalism suggests that the US is better than other countries, has a superior culture, or has a unique mission to transform the planet and its inhabitants. The concept of the United States as an exceptional society has a long history, sometimes traced back to French writer Alexis de Tocqueville or to the ideas espoused by the Founding Fathers of the United States during the American Revolution.

Poinçonnement des ponts-dalles précontraints

Aurelio Muttoni, Miguel Fernández Ruiz, Thibault Clément

Dans le domaine des ponts, les ponts-dalles appuyés sur de colonnes sont très souvent employés pour franchir des portées petites ou moyennes. Or dès que les portées commencent à devenir importantes, au-delà de 15 à 20 m environ, le recours à la précontrain ...

Schweiz. Verband der Strassen und Verkehrsfachleute (VSS)2013