Ultimate strength and fatigue resistance of grouted tubular joints

Several authors have pointed out the interest of combining steel with a cement or concrete grout for designing efficient tubular connections, both for static strength and fatigue resistance. However, the designers are faced with a lack of published data to be able to assess and implement this technique. Applications are thus relatively rare and limited principally to repairing or strengthening existing structures. A 4-year research project has been recently completed to improve the understanding of the behavior of grouted connections. Principal achievements include the testing of 14 large scale grouted prototype joints, finite element analyses and an improvement of the grouting material. This paper presents an overview of the main results of the project, with special attention to the validation of numerical models. Numerical modeling of composite joints can complement experiments but analyses are complex and lengthy. Simplified design method or design formulae are still useful.