Colonnades, Rome
Objects: 284 columns around St. Peter's Square (Vatican)
Building Material: Travertin
Typ of Soiling: Environmental pollution (acid rain, vehicle emissions)
Cleaning Equipment: Blasting gun with compressed air, environment-friendly abrasive (calcium cabonate) and reduced water flow (HDS 1195)
Period of Cleaning: July - October 1998
Building Material: Travertin
Typ of Soiling: Environmental pollution (acid rain, vehicle emissions)
Cleaning Equipment: Blasting gun with compressed air, environment-friendly abrasive (calcium cabonate) and reduced water flow (HDS 1195)
Period of Cleaning: July - October 1998