Proceedings e report - Firenze University Press

AGEING OF WOOD – DESCRIBED BY THE ANALYSES OF OLD BEAMS
The x-ray densitometric analyses of the 10 beams showed not consistent trends (from pith to bark).
Some samples confirmed the trends of the wood density determined at the “macro-samples”, showing
decreasing density trends (at the outer part of the radius – see Fig. 4.). Other samples seemed to be
unaffected (Fig. 5.) by ageing effects. They show increasing wood density (mean latewood density,
mean earlywood density and mean ring density).
Comparing the profiles of mean ring density and latewood percentage (Fig. 6) the loss of density due
to “ageing effects” can be seen clearly (starting at cambial ring 96). The trend of the mean ring density
started to decrease while the trend of the latewood percentage is almost stable.
Wood density (kg/m³)
1100
900
700
500
300
100
1 26 51 76 101 126
Cambial rings (Nr.)
Fig. 4: Density profile from pith to bark. Mean latewood density (top); mean ring density (middle); mean
earlywood density (bottom); sample N1
Wood density (kg/m³)
1100
900
700
500
300
100
1 26 51
Cambial rings (Nr.)
Fig. 5: Density profile from pith to bark. Mean latewood density (top); mean ring density (middle); mean
earlywood density (bottom); sample W3
Wood density (kg/m³)
900
800
700
600
500
400
300
200
1 26 51 76 101 126
Cambial rings (Nr.)
44
100
80
60
40
20
0
Latewood percentage
(%)
Fig. 6: Mean ring-density (bold line) and Latewood percentage (thin line) profile from pith to bark. (sample N1)