Page 8 of European technical approval ETA–11/0390, issued on 27.08.2012
English translation prepared by CSTB
4.3.2.4
Calculation of the design anchorage length l
bd
Anchoring rebar
In the case of anchoring rebar, the design anchorage length l
bd
must be determined as follow:
l
bd
=
1
2
3
4
5
l
b,rqd
≥ l
b,min
where
1
,
2
,
3
,
4
,
5
determined according to EN 1992-1-1.Table 8.2.
Overlap joint
In the case of overlap joint, the design anchorage length l
bd
must be determined as follow:
l
0
=
1
2
3
4
5
6
l
b,rqd
≥ l
0,min
Where
1
,
2
,
3
,
4
,
5,
6
determined according to, EN 1992-1-1.Table 8.2 and 8.3
1
Influence of the shape of the rebar
1
= 1
for straight rebar
2
Influence of the concrete cover
0.7 ≤
2
≤ 1.0 calculated according to
EN 1992-1-1 Table 8.2
3
Influence of the confinement by transverse
reinforcement not welded to main reinforcement
3
= 1 because no transverse
reinforcement
4
Influence of the confinement by welded
transverse reinforcement
4
= 1 because no transverse
reinforcement
5
Influence of the confinement by transverse
pressure
0.7 ≤
5
≤ 1.0
6
Influence of the overlapping length
1.0 ≤
6
≤ 1.5
Nota: Examples of calculations are published in annexes 18 and 19 for concrete C20/25. Other values
can be calculated by using the above formulas.
4.3.2.5
Embedment depth for overlap joints with Hilti tension anchor HZA-R
The effective embedment depth is the same as the lap length l
v
= l
0
(see Annex 7, Figure 12).
The total embedment depth l
e.ges
shall be determined as follows (see Annex 7, Figure 12):
l
e.
ges
≥ l
0
+ l
e
with: l
0
= required lap length acc.
to Section 4.3.2 and to EN 1992-1-1
l
e
= length of the smooth shaft see also Annex 7, l
e
> c
1
If the clear distance between overlapping rods exceeds 4
d
s
, the overlap length shall be increased by
the difference between the actual clear distance and 4
d
s
.
4.3.2.6
Transverse reinforcement
The
transverse
reinforcement
required
in
the
zone
of
the
rebar
or
of
the
tension
anchor
HZA-R
connection must fulfil the requirement of EN 1992-1-1, section 8.7.4.
4.3.2.7
Connection joint
In
case
of
a
connection
being
made
between
new
and
existing
concrete
where
the
surface layer
of
the
existing
concrete
is
carbonated,
the
layer
should
be
removed
in
the area
of the
new
reinforcing
bar (with a diameter ds + 60mm) prior to the installation of the new bar.
The foregoing may be neglected if building components are new and not carbonated.
4.3.2.8
Additional provisions
The
concrete
cover
required
for
bonded-in
rebars
or
tension
anchor
HZA-R
is
shown
in
Table
3
of
Annex 8 in relation to the drilling method and the hole tolerance.
Furthermore the minimum concrete cover given in EN 1992-1-1, Section 4.4.1.2 shall be observed.
