Assessment of Deteriorated Concrete Cover by Combined While-Drilling Techniques

The assessment of concrete cover deterioration generally involves the analysis of cores taken from the structure. Nonetheless, monitoring the drilling operation is itself a way to scan the material condition at increasing depth, which comes at no extra cost once the acquisition of samples has been planned. As an example, the feed rate of the cutting tool proved to be a sensitive indicator of the local damage undergone by the structure. On the other hand, hammer drilling small holes is definitely a faster and less invasive alternative for determining the variability of the mechanical properties within the concrete cover. Although this method does not provide an undisturbed material sample, the visual inspection of the remaining hole (voids, delamination cracks, and color changes) and the analysis of the ground-concrete powder (chemo-physical analyses) proved to be a viable alternative to the traditional examination of cores.