Author(s)

Viet Ha Nguyen¹, Jean Mahowald¹, Sebastian Schommer¹, Stefan Maas¹, Arno Zuerbes²

¹Faculty of Science, Technology and Communication, University of Luxembourg, Luxembourg City, Luxembourg.
²Technische Hochschule, Bingen, Germany.

This paper discusses the influence of environmental factors and of normal material aging on the eigenfrequencies of concrete bridges based on monitoring data registered during 4 years of a specific bridge. It is a new composite steel-concrete bridge built in 2006 in Luxembourg. The measurements are analyzed and compared to literature data. The final objective is the use of real monitored eigenfrequencies for structural health monitoring and damage detection based on identification of stiffness losses in practical applications. Therefore, it is very important to identify and compensate for outdoor influences namely temperature, excitation force level and normal aging effects, like creep and shrinkage of concrete and their impact on material properties. The present paper aims at describing these effects in order to separate them from damage effects. It is shown that temperature change rates and temperature gradients within the bridge have an influence on the eigenfrequencies. Hence the key idea for assessment from the full database is to select only measurements with small temperature differences and slow temperature change rates.

Damage Detection, Long-Term Monitoring, Eigenfrequency, Aging, Temperature

Nguyen, V. , Mahowald, J. , Schommer, S. , Maas, S. and Zuerbes, A. (2017) A Study of Temperature and Aging Effects on Eigenfrequencies of Concrete Bridges for Health Monitoring. Engineering, 9, 396-411. doi: 10.4236/eng.2017.95023.