Product specifications

The Formwork Experts
28 999759002 - 06/2008 Ü
User information Doka heavy-duty supporting system SL-1
Pre-tensioning the tie-rods
using the Split nut SL-1 15.0
Elongation of the form-ties as a percentage of the
length of rod under load
Example:
● Anchor load Z
k
: 50 kN
● Tie-rod 15.0; Length: 6 m
➤ In the diagram, find out the tie-rod elongation for
a value of 50 kN with reference to Line (A) (Tie-
rod 15.0). In our example, this is approx. 0.13%.
➤ 0.13% of a form-tie length of 6 m (6000 mm) cor-
responds to a tensioning distance of approx.
8mm.
Pre-tensioning procedure:
➤ Screw the Split nut SL-1 together completely, by
hand.
Overall length a = 90 mm
➤ Screw the Split nut B onto the Tie-rod 15.0 by
hand.
➤ Set the distance b=calculated tensioning distance
+ the 20 mm of the Hexagon nut 15.0 (C) .
➤ Tighten the split nut with a n° 41 combination
wrench (A) so as to tension the tie-rod. When
doing this, hold the inside of the split nut with a
n° 30 combination wrench (B) to prevent it turn-
ing.
1 rotation = 1.5 mm
Tensioning distance max. 20 mm
➤ Tighten the Hexagon nut 15.0 (C) with the Combi-
nation wrench 30 (B) .
Caution!
with all pre-tensioning methods - risk of
fracture from one-sided loading and over-
loading!
➤ Pre-tensioning and loosening should
always be done alternately - approx.
1 turn per nut.
➤ The tensioning distances (required ten-
sioning force) will be decided by the Doka
statics departments alone.
☞
In the statical calculation, allow for the pre-
tensioning condition as a separate loading
case!
Anchor load Z
k
[kN]
Elongation of the length of rod under load [%]
A Tie-rod 15.0
B Tie-rod 20.0
9736-103
0
0
5050
100
140
0.05
0.10
0.15
0.13
0.20
0.25
0.30
0.35
A
B
9759-258-02
a
9759-258-01
b
41
30
C
9759-259-01
B
A
9759-262-01
C
B