Duration : 01.02.2017 – 31.01.2021
Supervisor : Professor Eugen Brühwiler
Doctoral Student : Imane Bayane
Crêt de l’Anneau Viaduct, object of the study
Over the last 70 years, new road-bridge decks were generally build of reinforced concrete. Repetitive loading due to rail and road traffic as well as material deterioration due to environmental conditions make bridge inspection and rehabilitation a necessity. Before any intervention is taken, it is important to perform bridge examination with non-destructive-testing (NDT) techniques for fatigue safety investigation.
Fatigue loading applied to reinforced-concrete decks may lead to damage of concrete or steel reinforcement. There are not clear cases where reinforced concrete decks of a bridge failed because of fatigue; nevertheless, fatigue is a determinant design criterion in current codes. When applying current code provisions to calculate the fatigue safety of existing structures, reinforced-concrete decks are generally found to have failed due to fatigue damage. Codes are very often based on over-conservative approaches. Therefore, it is required to set real examination of reinforced-concrete decks using a structural monitoring system before any intervention.
The first part of this research is about an evaluation of NDT techniques that can quantify fatigue damage evolution quantitatively for long-term monitoring. The second part is about applying AE technique and strain gauges for fatigue safety investigation of the reinforced-concrete deck of a composite concrete-steel viaduct. The last part of this work will present a monitoring method to inspect reinforced-concrete slabs after strengthening using a layer of UHPFRC. As such, the objectives of the current study can be summarized as the following :
- Define a monitoring strategy to evaluate fatigue safety of reinforced-concrete decks;
- Investigate fatigue safety of reinforced-concrete deck in a composite concrete-steel viaduct using the monitoring strategy;
- Inspect reinforced-concrete slabs after strengthening with a layer of UHPFRC.