Performance Over Time and Durability Assessment …
279
2 Experimental Layout Definition
The evaluation of the decay in thermal performance was conducted by means of
relative comparison of the temperatures profiles and flowmeter measurements performed at time zero and after two accelerated ageing cycles. The test sample was
placed at the “door configuration” of the climatic chamber: thanks to this configuration, it was possible to simulate the actual behaviour of the sample as the enclosure
element between an internal environment (that of the same laboratory) and an external environment (the one imposed inside the climatic chamber). With this in mind,
it was decided to perform a sampling that would be appropriately placed in front of
the compartment of the climatic chamber, constituting the closing element (hence
the “door configuration” designation).
To achieve so, according to the stratigraphy for monitoring the test sample, the
size of the sample together with the correct positioning of the temperature sensors
and the flowmeter was organised; in the sample, some probes were also positioned
in the internal layers in order to verify the thermo-hygrometric profiles of the entire
stratigraphy.
The accelerated ageing was programmed in such a way to be able to monitor the
thermal properties of two tested coating types over time:
– natural stone (“NAT” type);
– artificial stone (“ART” type).
The accelerated ageing cycle is structured, as shown in Table 2, in two sub-cycles:
winter and summer. This cycle was designed based on years of research on thermal
insulation systems in the climate context of northern Italy, considering the average
frequency of critical events of winter freezing–thawing and summer heat shock on a
statistical basis (Daniotti et al. 2008).
Table 2 Specifications of the adopted accelerated ageing cycle
Subcycle
Phase
Air temperature
(°C)
RH (%) Phase
duration
(min)
Included
transitory
duration
(h)
Repetition Total
duration
(h)
Winter
Rain
5 ± 1 100
60
6
10
60
Freeze
−20 ± 1 –
90
Winter
heat
30 ± 1 50 ± 1
60
Summer
(thermal
shock)
Dry heat
80 ± 1 15 ± 1
60
3
25
75
Rain
20 ± 1 100
60
279
2 Experimental Layout Definition
The evaluation of the decay in thermal performance was conducted by means of
relative comparison of the temperatures profiles and flowmeter measurements performed at time zero and after two accelerated ageing cycles. The test sample was
placed at the “door configuration” of the climatic chamber: thanks to this configuration, it was possible to simulate the actual behaviour of the sample as the enclosure
element between an internal environment (that of the same laboratory) and an external environment (the one imposed inside the climatic chamber). With this in mind,
it was decided to perform a sampling that would be appropriately placed in front of
the compartment of the climatic chamber, constituting the closing element (hence
the “door configuration” designation).
To achieve so, according to the stratigraphy for monitoring the test sample, the
size of the sample together with the correct positioning of the temperature sensors
and the flowmeter was organised; in the sample, some probes were also positioned
in the internal layers in order to verify the thermo-hygrometric profiles of the entire
stratigraphy.
The accelerated ageing was programmed in such a way to be able to monitor the
thermal properties of two tested coating types over time:
– natural stone (“NAT” type);
– artificial stone (“ART” type).
The accelerated ageing cycle is structured, as shown in Table 2, in two sub-cycles:
winter and summer. This cycle was designed based on years of research on thermal
insulation systems in the climate context of northern Italy, considering the average
frequency of critical events of winter freezing–thawing and summer heat shock on a
statistical basis (Daniotti et al. 2008).
Table 2 Specifications of the adopted accelerated ageing cycle
Subcycle
Phase
Air temperature
(°C)
RH (%) Phase
duration
(min)
Included
transitory
duration
(h)
Repetition Total
duration
(h)
Winter
Rain
5 ± 1 100
60
6
10
60
Freeze
−20 ± 1 –
90
Winter
heat
30 ± 1 50 ± 1
60
Summer
(thermal
shock)
Dry heat
80 ± 1 15 ± 1
60
3
25
75
Rain
20 ± 1 100
60