LIBS
LIBS-RFID quality monitoring system
To fully realize a circular economy for concrete waste, we must retain material value and guarantee its quality. The industry hesitates to substitute virgin with recycled materials due to perceived variability in quality and the cost of assessing recycled product usability for concrete production. Therefore, for effective circularity, we must ensure product quality meets industry standards and transparently display this quality for recycled aggregates.
To remove this bottleneck, C2CA Technology designed a patented system through which the aggregate quality can be assessed and then traced throughout the value chain.
The system is made of an in-line Laser-Induced Breakdown Spectroscopy (LIBS)[1] -based online sensor system that can continuously measure and control the quality and homogeneity of the aggregates produced by the ADR (5000-10000 chemometric analyses per ton) (see Figure 5).
[1] LIBS is a plasma emission spectroscopic technique where the spectrum is representative of the elemental composition of the material and also highly characteristic for the material type in case of fingerprinting.
The LIBS-based device works in tandem with an RFID tracking system and a vast cloud database. The RFID tags record quality data from the LIBS system and synchronize it with the cloud databases. Each product fraction has a unique info carrier assessed by the LIBS system, solving the quality assurance issue as the labels match their respective materials. This improves the transparency and reliability of the recycled product information, also simplifying access. The data includes quality, properties of the demolished concrete, demolition method, original use and location, transportation method, original building owner, demolition firm, etc. This data aids users in designing an optimal new concrete mix, considering the recycled product quality and intended application. The RFID carriers are easily detected by affordable RFID readers, even when not visible or embedded in the recycled or final product (see Figure 6).
Figure 6. The RFID reader and writer system (left). RFID embedded in concrete (right).
Figure 5. The LIBS-based quality assessment system.