SETTLING OF A BITUMINOUS COAT ON AN ORTHOTROPIC PLATE

The bituminous surfacings of orthogonally anisotropic steel deck structures (orthotropic plate) undergo repeated deformations characterized by the alternation of positive and negative moments. These stresses are particularly severe and can cause a longitudinal cracking "by the top", or a separation of layers of bituminous mix from its support. The laboratory studies preceding the construction of the viaduct of Millau (France) provide the opportunity of new progress in the settling of these coatings and to compare the performances of modified binders. Through this example, the article presents the specific testing equipment developed for this work, and a summary of the results. For the covering abstract see ITRD E121480.