In order to test the laser-scanning device presented by Stanić, Lepot, Catieau, Langeveld and Clemens [1], laboratory experiments have been performed. Various objects, covering a wide range of sizes, shapes, materials, colours and reflectiveness, have been installed in a concrete pipe and scanned by the prototype in order to identify potential object characteristics that may affect measurement uncertainty and/or create bias. By taking into account both uncertainties (on scanned and measured sizes), scanned dimensions have been compared to measurements performed with a calliper or a ruler: overall the values are mutually consistent. The proposed prototype is suitable for sewer inspections: displaced joints, cracks, deposits can be accurately measured without any bias by comparison to CCTV. Uncertainty in the measurement appears to be unaffected by humidity or fat deposits.

Drill core samples are taken in practice for an analysis of the material characteristics of concrete pipes in order to improve the quality of the decision-making on rehabilitation actions. Earlier research has demonstrated that core sampling is associated with a significant uncertainty. In this paper, the results of core samples are compared with the results of full-scale pipe cracking lab experiments. It is shown that the concrete of deteriorated sewer pipes shows a significant variability in material characteristics. Further it is shown that the formation of ettringite due to biochemical sulphuric corrosion is not necessarily limited to the crown of the pipe and also degradation of pipe material, measured by the carbonation depth, is occurring at the inside and outside of the pipe. It is concluded that tensile splitting strength and the carbonation depth are the two material property parameters of core sampling with a sufficiently high correlation (R² > .90) with the structural strength of the pipe. The thickness of the remaining ‘healthy’ concrete material is the optimal parameter, as this requires the smallest sampling size.