non destructive concrete strength tests 24 concrete reinforcement detection 24 core drilling 20 concrete strenght 20 reinforcement 15 grouting 14 steel reinforcement 14 buildings 13 gunite 12 houses 12 fiber reinfoced polymers 10 photographic documentation 9 restoration of corroded concrete 9 concrete repairs 9 industrial builidngs 8 undisturbed cutting 7 reinforcement, restoration of buildings 7 mass homogenization 7 mortar protection 6 resin injections 6 hydroblast 5 anchors 5 carbonation depth 5 Schmidt Hammer tests 5 pull-off test 4 shotcrete 4 composite materials 4 hotels 4 corrosion inhibitor 4 sealing 4 bolts 4 landmark buildings 4 cement injections 4 Ultra Sound Velocity Tests 4 metal beams 3 bridges 3 coating 3 metal sheets and coats 3 fireproofing 2 carbon fiber 2