Smart Aggregates and Wave Interferometry in Short-Term Static Load Tests on Zeeland Bridge

Abstract

The Zeeland Bridge (Zeelandbrug) is a 5 km multi-span prestressed-concrete bridge in the Province of Zeeland, the Netherlands, completed in 1964. To reduce the uncertainties inherent in structural re-assessment, a dedicated two-year field lab has been established, focusing on long-term monitoring and targeted load testing. Within this field lab, four cross-sections across two typical spans have been instrumented with Smart Aggregates (SA) (embedded piezoelectric transducers), Fiber Bragg Grating (FBG) strain sensors, and numerous temperature and humidity sensors. The latter enables compensation for environmental effects. Static load tests were conducted using a 50-tonnes truck at different positions across the spans. Wave Interferometry (WI) was applied to the SA signals to extract wave velocity changes; these changes are potential indicators of microstructural changes or stress redistribution. The preliminary results obtained during the static load tests at different loading conditions revealed changes in wave velocity in the concrete. These findings are compared with local strain measurements from co-located FBG sensors. This enables combined analysis of both wave velocity changes and strains under static loads. The outcomes of this research will not only improve the understanding of the structural behaviour of typical spans of the Zeeland Bridge under static load conditions, but also assess the feasibility of using SAs and WI technology for long-term structural health monitoring of concrete bridges.