Field measurements at a composite bridge with composite dowels as shear connectors - Economical Bridge Solutions based on Innovative Composite Dowels and Integrated Abutments - page 60

Field measurements at a composite bridge with
composite dowels as shear connectors

Markus Feldmann 1 , Daniel Pak 1 , Maik Kopp 1 & Nicole Schillo 1

Keywords: composite bridge, composite dowel, external reinforcement, hot-spot stress, in-
situ measurement, railway bridge, rail support

Abstract: Within the demonstration project ECOBRIDGE, funded by the Research Fund
for Coal and Steel (RFCS), a monitoring program has been developed and applied to survey
a composite railway bridge. The stress distribution between concrete and specially designed
composite dowels, which have a better fatigue resistance compared to conventional headed
studs, has been investigated as well as the forces in several rail support points. The German
railway operator DB Netz AG requested the survey to prove the applicability of state of the
art calculation methods, which were not part of compulsory codes.

1. Pilot bridge Simmerbach

In the course of railway track 3511 between Bingen and Saarbrücken (Germany), two exist-
ing steel troughs with ballast bed, which had reached their life-span, have been replaced by
two VFT-Rail ® girders with a span of 17.75 m each (“Fig. 2”). The composite VFT-Rail ®
system is characterized by two characteristics: first, composite action between concrete and
steel girders (which act as external reinforcement) is ensured by means of composite dowels.
These are cut out of an I profile (“Fig. 1”, right). Second, the rail support points are directly
fastened to the composite girder (“Fig. 1”, left).

Figure 1: Transverse cross section (left) VFT-Rail ® with rail support points directly fas-

tened to the superstructure and composite dowel and longitudinal cross section
(right, depicting the clothoidal shape of the dowels).