Hyperspectral imaging applied to demolition waste recycling: Innovative approach for product quality control

Hyperspectral imaging (HSI) based sensing devices were utilized to develop non-destructive, rapid and low cost analytical strategies finalized to detect and characterize materials constituting demolition waste. More in details, HSI was applied for quality control of high-grade recycled aggregates obtained from end-of-life (EOL) concrete. The described HSI quality control approach is based on the utilization of a platform working in the near infrared range (1000-1700 nm). The acquired hyperspectral images were analyzed applying different chemometric methods: principal component analysis (PCA) for data exploration and partial least square-discriminant analysis (PLS-DA) to build classification models. Results showed that it is possible to recognize the recycled aggregates from different contaminants (e.g.: brick, gypsum, plastic, wood, foam, etc.), allowing the quality control of the recycled flow stream.