Reinforced concrete beam subjected to bending
Source: BAM
The freight volume transported by trucks in Germany has been increased in recent years and poses a substantial problem to the transport infrastructure. It is assumed that the freight volume increases further in the coming years. Especially old bridges are affected by the increasing traffic loads. The further use of these pre-damaged bridges needs substantial repair, or if this is not possible, a reconstruction of the old bridges. Detailed and reliable information on the remaining load bearing capacity is the basis for the decision-making process considering repair or reconstruction of the damaged structures. In this context, Structural Health Monitoring (SHM) is a useful tool for evaluating the condition of engineering structures and to ensure safe operation until repair or reconstruction is finished and which eventually helps to reduce costs due to unscheduled closings of the damaged structures. Furthermore, SHM can be used for condition monitoring after repair.
Within the BAM internal project „BLEIB - Assessment, lifetime prediction and reconstruction of bridges” new methods and innovative techniques for condition analysis and condition monitoring of bridges have been developed and validated on a reference structure. For experimental validation, a bridge demonstrator with a span of 2 x 12 m was built on the BAM Test Site for Technical Safety (BAM TTS). Preliminary test on reinforced concrete beams have been conducted to investigate the application, handling, and synchronization of various non-destructive measuring systems. For this purpose, the deformation behaviour of a reinforced concrete beam was investigated in a four-point-bending test on laboratory scale. The focus was on the characterization of the main failure modes and the resulting crack formation using different optical measuring techniques. In this article, the results of fibre optical and photogrammetric measurements obtained on a reinforced concrete beam in bending are presented and compared with classical measuring techniques (e.g. deformation measurements using linear variable differential transformer).
The load-bearing behaviour of a reinforced concrete beam investigated by optical measuring techniques
Götz Hüsken, Stephan Pirskawetz, Detlef Hofmann, Frank Basedau, Klaus-Peter Gründer, Daniel Kadoke
published in Materials and Structures, Vol. 54, issue 3, article 102, 2021
BAM division Building Materials, division Technology of Construction Materials, division Sensors, Measurement and Testing Methods, division Fibre Optic Sensors