Issue 40

M. Mentzini, Frattura ed Integrità Strutturale, 40 (2017) 95-107; DOI: 10.3221/IGF-ESIS.40.09 102 Drum 8.8 The ancient member is characterized by two losses of material sited in opposite areas all over its height. To restore the drum’s volume two supplements of new marble are created. Their join to the ancient remain core was accomplished by in- serting titanium bars which were parallel to the member’s upper side from the fractured area (Figs.12a,b). This reinforce- ment is the proper one to avoid overturning of the supplements, before the overturning of the drum as a whole. (a) (b) Figure 12 : (a) Joining the first supplement. (b) Joining the second supplement. On the left the first –raw- supplement is already joined. Drum 9.5 Although the drum seems intact, a fracture plane runs across its upper side and through its mass –allover its height- reaching the center of the lower side. Both upper and lower sides were carved during N. Balanos’ restoration and three iron clamps -of double “T” shape- were inserted (two clamps on the upper side and one on the lower one). Nowadays the restoration of the drum requires more reinforcement, therefore the iron clamps were substituted by new ones made of titanium and some extra reinforcement was also added. The additional reinforcement (titanium bars) was inserted in certain areas through both sides of the drum and their direction was 30 o with respect to the horizontal level in order to succeed the proper combination of bars’ strength and forces lever arm (Figs.13a,b,c). The required moment was calculated so as to avoid the separation of the drum in two fragments i.e. to succeed the stability of each one. (a) (b) (c) Figure 13 : (a) Inserting reinforcement on the upper side. (b) Inserting reinforcement on the lower side. (c) Inserting reinforcement bar to repair a small crack on the upper side through the Balanos’ mortise, before replacing the clamp. Drum 10.9 Although the drum maintains its shape, a fracture plane runs across its upper side and through its mass - all over its height - reaching the lower side of the drum all over its width (Fig.14a). Three iron clamps - of double “T” shape - were placed in mortises carved on the surface of the drum, during N. Balanos’ restoration, to repair the crack only on the upper side. Nowadays the restoration of the specific drum requires more reinforcement. The iron clamps were replaced by new titanium ones and the additional reinforcement (titanium bars) was inserted normal to the fracture plane, from areas of the drum’s view which exhibit marks of decay and having lost their original ancient surface (Fig.14b, Fig.15), so as to achieve the