Meeting of the experts responsible for bridge load assessment (FvBel) of the German Railways (DB) from 25/01/2017-26/01/2017 in Fulda

To this year's meeting of the experts responsible for bridge load assessments KREBS+KIEFER was invited by DB (German Railways) Network AG to deliver a lecture on the experience in the testing of existing bridges.

The subject of the lecture was the DB concept for railway bridges with stress-prone pre-stressed steel, which are awaiting trial implementation.

The re-calculations are necessary for older pre-stressed concrete bridges, the tensioning elements which are made of pre-stressed steel with high sensitivity against hydrogen-induced stress corrosion cracking (Sigma Oval, Neptune, Hennigsdorfer pre-stressed steel). The aim is to demonstrate sufficient pre-failure demonstration behaviour, i.e. the occurrence of cracks at detectable construction sites as a warning of the bridge load-bearing loss or the establishment of appropriate measures for achieving adequate safety.

In an approximately two-hour lecture on detection possibilities, the proofing principle and strengthening measures, the experiences of KREBS+KIEFER in the testing of road bridges with the instructions for stress corrosion cracking (roads) already in use for several years were presented by Mrs. Annett Mähl (test engineer for railway construction) and Mr. Steffen Böhm (test engineer).

The possibilities of the extended beam bending (ETB) by KREBS+KIEFER with verification proof as well as strengthening options for existing bridges, such as the inclusion of external tensioners and cross-section additions, were of great interest to the DB specialists in bridge loading.

As a result of the report, KREBS+KIEFER was recognised as a post-test calculation specialist for DB.