ETA120354 BeA screws core r1 - ETA-Danmark

Page 8 of 17 of European Technical Approval no. ETA-12/0354
0,8
⎧ fax,k ⋅d ⋅l ef ⋅k1 ⋅ k2
⎛ ρk
⎞ ⎫
⎪ ⋅
2 2 ⎜
350
⎟ ⎪
⎪ 1,2 ⋅cos α + sin α ⎝ ⎠ ⎪
F = min
ax , α ,Rk ⎨ 0,8 ⎬
⎪ ⎧ 2 fax,k ⋅d ⋅l ef ,B ⋅ k1 ⋅k
2 ⎫ ⎛ ρk
⎞ ⎪
⎪max ⎨fhead,k ⋅d h ;
⋅
2 2 ⎬ ⎜
1,2 cos sin 350
⎟
⋅ α + α
⎪
⎩ ⎩ ⎭ ⎝ ⎠ ⎭
Where
Fax,α,RK Characteristic axial capacity of the screw at
an angle α to the grain [N]
d Outer thread diameter [mm]
Point side penetration length of the threaded
lef
part according to EN 1995-1-1:2008 [mm]
lef,B Length of the threaded part in the batten
[mm]
α Angle between grain and screw axis (α > 30°)
k1 min {1; 220/tHI}
min {1; σ10%/0,12}
k2
tHI
σ10%
fhead,k
dh
ρk
Thickness of the thermal insulation [mm]
Compressive stress of the thermal insulation
under 10 % deformation [N/mm²]
σ10% ≥ 0,05 N/mm²
Characteristic head pull-through parameter
[N/mm²]
Outer diameter of the screw head [mm]
Characteristic density of the batten or rafter,
respectively [kg/m³]
Fixing of battens with alternatively inclined screws
The analysis of the fixing of the insulation and battens,
respectively, may be carried out using the static model in
Annex B. The battens must have sufficient strength and
stiffness.
The characteristic axial tensile capacity of the BeFIX TKD
screws for rafter or facade insulation shall be calculated
from:
F = min
ax , α ,Rk
0,8
⎧ fax,k ⋅d ⋅l ⎫
ef ,b ⎛ ρb,k
⎞
⎪ ⋅⎜ ⎪
2 2 ⎟
⎪1, 2⋅ cos α + sin α ⎝ 350 ⎠ ⎪
⎪ 0,8 ⎪
⎨ fax,k ⋅d ⋅l ef ,r ⎛ ρr,k
⎞ ⎬
⎪ ⋅
2 2 ⎜ ⎟ ⎪
⎪1,2 ⋅cos α + sin α ⎝ 350 ⎠ ⎪
⎪f ⎪
⎩ tens,k
⎭
The characteristic axial compressive capacity of the BeFIX
TKD screws for rafter or facade insulation shall be
calculated from:
F = min
ax , α ,Rk
Where:
0,8
⎧ fax,k ⋅d ⋅l ⎫
ef ,b ⎛ ρb,k
⎞
⎪ ⋅⎜ ⎪
2 2 ⎟
⎪1, 2⋅ cos α + sin α ⎝ 350 ⎠ ⎪
⎪ 0,8 ⎪
⎨ fax,k ⋅d ⋅l ef ,r ⎛ ρr,k
⎞ ⎬
⎪ ⋅
2 2 ⎜ ⎟ ⎪
⎪1,2 ⋅cos α + sin α ⎝ 350 ⎠ ⎪
⎪F ⎪
⎩ ki,Rk
⎭
Free screw length
[mm]
BeFIX TKD
8,0 mm
Fki,Rk [kN]
≤ 120 5,97
140 4,59
160 3,62
180 2,93
200 2,42
220 2,03
240 1,72
260 1,48
280 1,29
300 1,13
320 1,00
340 0,89
360 0,80
380 0,72
400 0,65
420 0,59
2.7 Related aspects of serviceability
2.7.1 Corrosion protection in service class 1 and 2.
The BeFIX screws are produced from carbon wire. Screws
made from carbon steel are electrogalvanised and yellow or
blue chromate. The mean thickness of the zinc coating is
5µm.