Foto des Belastungsfahrzeugs für Brückenprüfungen

Load testing can be used to reliably determine the bearing capacity of bridges, usually identifying significant reserves compared to calculations. Decisions for or against demolition/replacement or repair/reinforcement can be made quickly and objectively, based on verifiable criteria.

The BELFA load testing vehicle was developed to perform on-site load tests more quickly and cost-efficiently. Using the load testing vehicle helps to reduce blocking times that are undesirable for economic reasons, and a perforation of the sealing layer can usually be avoided, too.

Contact person

Prof. Dr.-Ing.
Elke Reuschel

T +49 (0)341 6582-143
F +49 (0)341 6582-181

e.reuschel@mfpa-leipzig.de

Further information
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Longer operating life

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Higher load capacity

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Objective and risk-free testing

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Short blocking periods

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Quick result

Driving statusl = 22,5 m
Testing statusl = 22,5 bis l = 35,8 m
Support (brackets)a = 6,0 to a = 18,00 m
Vehicle mass (without ballast)G = 73 t
Steel ballastP = 7,8 t
Water ballastP = 20 t

Since its first use in 2001, about 60 bridges made of reinforced concrete, prestressed concrete, compressed concrete and masonry have been examined using the BELFA. Project partners from the Bremen City University of Applied Sciences, TU Dresden, Bauhaus University Weimar and HTWK Leipzig/MFPA Leipzig were involved in these tests.

Compared to pre-calculations, the load capacity verified was 30 to 50% higher, and in individual cases up to 150% higher, without reducing the level of safety.

The BELFA was comprehensively modernised and converted in 2015, and has since been operated by MFPA Leipzig GmbH. It was first used on the Gustav Esche Bridge in Leipzig in August 2015.

Illustrierte Übersichtskarte Deutschland und Niederlande mit Standorten zum BELFA Einsatz
FAQ

Structures are usually calculated statically. However, calculation models for structures rely on simplifications regarding the geometry, construction material behaviour, load transfer, and so on. This is justified, as a useful life of around 100 years is assumed when planning new structures, and the model assumptions also provide for higher loads and busier traffic in the future, as well as taking ageing effects of materials into account.

The goal of load testing on existing structures with a past usage history, is to make statements about their current load-bearing capacity with a perspective for continued use for up to 20 years.

Load testing on a newly built structure made of new construction materials or of innovative design allows for the model assumptions made to be verified or improved

Load testing is therefore not an alternative to statical calculations, but a useful supplement if model assumptions are unclear or if the following conditions apply:

  • Poor structural condition and weakened bearing cross-sections due to corrosion, crack formation, concrete spallation, moisture penetration, etc.
  • Damage to the structure following unusual events (fire, explosion, flooding, impact, changes to the subsoil)
  • Incomplete or missing planning documentation that cannot be fully restored (reinforcement structure, prestress, special components)
  • Innovative construction materials, composite material solutions, lack of experience with particular designs
  • Admissible traffic load or load capacity
  • Possibly necessary traffic restrictions or refurbishment measures
  • Confirmation of successful refurbishment measures (e.g. for unclear compound structures)
  • System identification
  • Remaining useful life if combined with monitoring

 

This means that load testing provides for an objective, verifiable basis for decision-making for public authorities at short notice, concerning demolition/refurbishment/continued use for a limited or unlimited time. Decisions regarding the efficient use of existing resources can be made at a high level of planning security. If needed, building monitoring can take place after load testing, to observe the progress of any damage or overloading by vehicles (possibly in cooperation with the police).

  • Support spans of the bridge spans up to 18 m (for larger support spans special solutions for load investigations can be individually configured – please inquire!)
  • Verification of bridge classes 12 to 60 according to DIN 1072 (recalculation guideline) or load models according to Eurocode or DIN technical report (maximum load in one lane up to 1500 kN, secondary lane and remaining areas via stepwise ballasting(recalculat or load moculngle-block-padding">
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