Proceedings e report - Firenze University Press

DISINFECTION AND CONSOLIDATION BY IRRADIATION OF WOODEN SAMPLES FROM THREE ROMANIAN CHURCHES
Fig. 3 shows the diagrams for penetration test applied at sets of consolidated and non-consolidated
samples. From all above diagrams it can be noticed that the consolidated samples have higher
resistance to penetration in comparison with the non-consolidated samples. This means that the wood
fiber impregnated with styrene resin is more resistant at penetration.
Stress in MPa
150
100
50
Stress in MPa
20
15
10
5
0
0,0 0,5 1,0
Strain in mm
1,5 2,0
Stress in MPa
14
12
10
8
6
4
2
0
0,0 0,5 1,0
Nominal strain in mm
1,5 2,0
0
0,0 0,5 1,0
Strain in mm
1,5 2,0
86
Consolidated A samples
Non-consolidated A samples
Consolidated B samples
Non-consolidated B samples
Consolidated C samples
Non-consolidated C samples
Fig. 4. Diagrams for application of bending test
Fig. shows 4 the diagrams for bending test applied at sets of consolidated and non-consolidated
samples. From all above diagrams it can be noticed that the consolidated samples have higher
resistance (about 2-3 times) to bending in comparison with the non-consolidated samples. It can be
also noticed that consolidated samples crush faster than non-consolidated samples after the appearance
of first small crushes in their structure. This means that the wood fiber impregnated with styrene resin
is more resistant at bending and after the appearance of first small crushes in structure the flow to total
crush is short.
The presence of any free radical in an object gives a potential risk of its damage. Objects containing
cellulose have natural free radicals. Irradiation treatment induces in any object free radicals and their
persistence could constitute a damage risk. Considering these facts, the intensity of ESR signal of
cellulose free radicals it has been used in order to evaluate the potential risk of damage for
consolidated and non-consolidated samples. In order to be able to compare them, the intensities were
brought at same gain. As can be seen in Table 3, the treated samples have shown three months after