In order to investigate the behaviour of the Acropolis walls, the Acropolis Restoration Service, an authority subordinate to the Greek Ministry of Culture, initiated an instrument-based monitoring project and had a network of so-called “fibre bragg grids” installed on the walls of the north, east and south walls. These are optical filters that allow certain areas of light waves to pass through but reflect others. The network’s highly sensitive sensors continuously provide a control centre with information about the degree of deformation of the walls and the condition of particularly vulnerable zones. In this way, structural assessments can be made and limit values set.
The FBN II is characterised by the expansion clip and the conical bolt. The anchor is characterised by easy handling and quick installation: Drill the hole, knock in the bolt with a few blows of a hammer and tighten. When the hex nut is tightened, the conical bolt is pulled into the expansion clip and tensions it against the drill hole wall. The bolt geometry enables optimal load distribution, which means that the anchors can also be safely processed close to the edge.
In addition to the standard version, there is a short version FBN IIK with short anchoring depth. The FBN II has the European Technical Assessment (ETA) for uncracked concrete (option 7).
