European technical approval
ETA-09/0295
English translation prepared by DIBt
Page 7 of 32 | 9 May
2013
Z38892.13
8.06.01-155/13
-
use of a guide device (drilling aid) for drilling holes close to edges (if necessary),
-
kind of preparation of the joint between building component being connected including the
diameter and thickness of concrete layer that has to be removed.
4.3
Design
4.3.1
General
-
The actual position of the reinforcement in the existing structure shall be determined on
the basis of the construction documentation and taken into account when designing.
The design of post-installed rebar connections according to Annex 2 and determination of the
internal section forces to be transferred in the construction joint shall be verified in accordance
with EN
1992-1-1:2004. When ascertaining the tensile force in the rebar, allowance shall be
made for the statically effective height of the bonded-in reinforcement.
Hilti tension anchor HZA-R according to Annexes 6 and 7 shall be designed for the welded-on
reinforcement steel B500B. The length of the bonded-in smooth shaft made of stainless steel
may not be accounted as anchorage.
The verification of the immediate local force transfer to the concrete has been provided.
The verification of the transfer of the loads to be anchored to the building component shall be
provided.
The spacing between post-installed rebars respectively Hilti tension anchor HZA-R shall be
greater than the minimum of 5 d
s
and 50 mm (according to Annex 5 respectively Annex 7).
4.3.2
Determination of the basic anchorage length
The required basic anchorage length
™
b,rqd
shall be determined in accordance with EN 1992-1-1,
Section 8.4.3:
™
b,rqd
= (d
s
/ 4) (σ
sd
/
f
bd
)
with:
d
s
= diameter of the rebar
σ
sd
= calculated design stress of the rebar
f
bd
= design value of bond strength according to Annex 9, Table 5 or 6
in consideration of the coefficient related to the quality of bond conditions and of
the coefficient related to the bar diameter and of the drilling technique
4.3.3
Determination of the design anchorage length
The required design anchorage length
™
bd
shall be determined in accordance with EN 1992-1-1,
Section 8.4.4:
™
bd
= α
1
·
α
2
·
α
3
·
α
4
·
α
5
™
b,rqd
™
b,min
with:
™
b,rqd
= according to section 4.3.2
α
1
= 1.0 for straight bars
α
2
= 0.7…1.0 calculated acc.
to EN 1992-1-1, Table 8.2
α
3
= 1.0 because of no transverse reinforcement
α
4
= 1.0 because of no welded transverse reinforcement
α
5
= 0.7…1.0 for influence of transverse pressure acc.
to EN 1992-1-1, Table 8.2
™
b,min
= minimum anchorage length acc.
to EN 1992-1-1
= max {0.3
™
b,rqd
; 10d
s
; 100 mm} under tension
= max {0.6
™
b,rqd
; 10d
s
; 100 mm} under compression
In case of diamond wet drilling multiply the values by 1.5.
The maximum permissible anchorage depth is given in Annex
18 in relation to the dispenser to
be used.
