Modelling of mineral construction and demolition waste dynamics through a combination of geospatial and image analysis

As the construction sector is shifting towards circular economy models, the role of
mineral construction materials as main waste fraction in terms of volumes is crucial. A
characterization of this mineral stock, as well as the waste derived from it is decisive in
ensuring the application of the best practices of circular economy. This paper
describes a methodology for assessing the mineral building stock through a
combination of geospatial and image analysis. By analysing old topographic maps,
buildings are grouped according to their building age into different typologies and
based on these maps the construction and demolition activity is evaluated. The mineral
stock is assessed and estimations of the mineral construction and demolition waste
(CDW) is generated for different stochastic scenarios. This methodology is applied
exemplarily on the country of Luxembourg. It was found that the total mineral
construction stock for Luxembourg is 276.75 Mt and has been growing at a rate of
20.81% to 24.39% in the last 30 years. Furthermore, the study identified a mean age of
the urban building stock of about 60 years and a typical maximum building lifetime of
122 years. Based on the stochastic projections the mineral CDW generated from the
existing building stock is expected to be up to 226.9 Mt by 2100, while if future building
scenarios are considered, it can be as high as 885.3 Mt. The annual CDW production
is expected to be sufficient for a viable concrete recycling activity if regulations on the
waste volume flows are made available.