Cone Calorimeter Tests of Cross Laminated Timber (CLT)

Cone calorimeter test of Cross Laminated Timber (CLT) at DBI on the 16th May 2025. The samples originally had a thickness of 100 mm, but this was reduced to 40 mm before the test in order for the samples to fit under the cone. The samples are made of a mix of spruce and pine with an average density of 393 ±11.6  kg/m³. The specimens were tested with a heat flux directed parallel to the glued layers. 

The results from the six cone calorimeter test for CLT are presented in the following for three heat flux levels of 70 kW/m², 50 kW/m² and 35 kW/m², respectively. Two tests were performed at each heat flux level, and each test had a duration of 1500 s except one, which was 2500 s (the first test at 70 kW/m²).

Sample
Heat flux [kW/m²]
Test duration [s]
Ignition time [s]
Charring depth [mm]

CLT70-I
70
2500
11
40

CLT70-II
70
1500
12
25-30

CLT50-I
50
1500
19
20

CLT50-II
50
1500
18
20

CLT35-I
35
1500
44
15

CLT35-II
35
1500
39
15