Shear capacity of historical reinforced concrete beams

Reinforced concrete works, from the origins until the release of the first technical standards, were built by applying patented systems (e.g., Monnier's, Hennebique's) that were often the result of individual intuitions more than scientific and technical knowledge. This is one of the reasons that many of structures built in those years, and still surviving, could not be considered reliable with regard to the structural safety, as it is presently intended. In this scenario, the evaluation of R.C. beam shear capacity becomes crucial. In this article, analysing the tests carried out in Stuttgart in the early 20th century, a preliminary study on the shear capacity assessment of historical R.C. beams is presented. The aim is to verify the applicability to these kinds of beams of the relations given for new constructions in the present Eurocodes. Moreover, a novel formulation for the transversal shear capacity for historical R.C. beams with U-shaped plates is proposed.