The influence of rivet corrosion on the durability of riveted connections

From the beginning of structural steel construction until the 1950s, steel bridges were riveted structures. Rivets have not only been used for joining members as bolts are today used for but also for forming cross sections by joining the section elements e.g. web and flanges.
From this kind of bridges thousands - among many famous bridges - still fulfil the function that they have been erected for.
Rivets are often particular locations of accelerated corrosion in riveted bridges. In particular the heads of the rivets are subject of rust and corrosion. Therefore the question is whether and how much the pre-stressing effect of the rivet will be affected by the material degradation of the rivet's head, such that the load deformation and the fatigue behaviour will be reduced. The pre-stress of a rivet reduces the stress-peak that is caused by the hole in the connection and is thus of big importance for the fatigue resistance.
The following paper presents latest investigations on the effect of rivet head corrosion on the pre-stressing of the rivet by means of milling the rivet's head and numerical simulations. Fatigue tests are presented that give first results for the assessment of the residual lifetime of riveted connection with reduced rivet stress.
The paper also shows how the results of the investigations have been considered in an existing riveted bridge from 1920 of 2,3 km length.