Smart RFID Sensors Embedded in Building Structures for Early Damage Detection and Long-Term Monitoring.

Christoph Strangfeld,Matthias Bartholmai,Sergej Johann

doi:10.3390/s19245514

Christoph Strangfeld, Matthias Bartholmai + Show 1 more

Open Access

https://doi.org/10.3390/s19245514

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Abstract

In civil engineering, many structures are made of reinforced concrete. Most degradation processes relevant to this material, e.g., corrosion, are related to an increased level of material moisture. Therefore, moisture monitoring in reinforced concrete is regarded as a crucial method for structural health monitoring. In this study, passive radio frequency identification (RFID)-based sensors are embedded into the concrete. They are well suited for long-term operation over decades and are well protected against harsh environmental conditions. The energy supply and the data transfer of the humidity sensors are provided by RFID. The sensor casing materials are optimised to withstand the high alkaline environment in concrete, having pH values of more than 12. Membrane materials are also investigated to identify materials capable of enabling water vapour transport from the porous cement matrix to the embedded humidity sensor. By measuring the corresponding relative humidity with embedded passive RFID-based sensors, the cement hydration is monitored for 170 days. Moreover, long-term moisture monitoring is performed for more than 1000 days. The experiments show that embedded passive RFID-based sensors are highly suitable for long-term structural health monitoring in civil engineering.

Highlights

A safe and reliable infrastructure is the fundamental base for social coexistence and economic growth in our modern society
The experiments show that embedded passive radio frequency identification (RFID)-based sensors are highly suitable for long-term structural health monitoring in civil engineering
Systems will have a chance in the market. Structures such as bridges or tunnels have a service life of several decades. To cover this long time period and to enable the required robustness against the rough environment, passive RFID-based sensors are embedded into concrete

Summary

Introduction

A safe and reliable infrastructure is the fundamental base for social coexistence and economic growth in our modern society. The cumulative yearly investment in maintenance in the transport infrastructure amounts to ca. 13 billion euro in Germany [1]. Approximately 71% of all infrastructure degradation is caused by chloride-induced corrosion or by carbonation-induced corrosion [2]. Road freight transport will increase by approximately 40% in Germany between 2010 and 2030 [3]. This will lead to significantly increased loads, which will accelerate the degradation of existing infrastructure. In the United States of America the annual costs due to corrosion of highway bridges, as estimated in 2002, amounted to more than 8 billion [4]

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