|
SIST EN 1168:2005/oprA1:2007
01-oktober-2007
0RQWDåQLEHWRQVNLL]GHONL9RWOHSORãþH
Precast concrete products - Hollow core slabs
Betonfertigteile - Hohlplatten
Produits préfabriqués en béton - Dalles alvéolées
Ta slovenski standard je istoveten z: EN 1168:2005/prA1
ICS:
91.100.30 Beton in betonski izdelki Concrete and concrete
products
SIST EN 1168:2005/oprA1:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
EUROPEAN STANDARD
FINAL DRAFT
EN 1168:2005
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
July 2007
ICS 91.060.30; 91.100.30
English Version
Precast concrete products - Hollow core slabs
Produits préfabriqués en béton - Dalles alvéolées Betonfertigteile - Hohlplatten
This draft amendment is submitted to CEN members for unique acceptance procedure. It has been drawn up by the Technical Committee
CEN/TC 229.
This draft amendment A1, if approved, will modify the European Standard EN 1168:2005. If this draft becomes an amendment, CEN
members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of this amendment
into the relevant national standard without any alteration.
This draft amendment was established by CEN in three official versions (English, French, German). A version in any other language made
by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1168:2005/prA1:2007: E
worldwide for CEN national Members.
---------------------- Page: 2 ----------------------
EN 1168:2005/prA1:2007 (E)
Foreword
This document (EN 1168:2005/prA1:2007) has been prepared by Technical Committee CEN/TC 229 “Precast
concrete products”, the secretariat of which is held by AFNOR.
This document is currently submitted to the Unique Acceptance Procedure.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document.
2
---------------------- Page: 3 ----------------------
EN 1168:2005/prA1:2007 (E)
1 Modification to Clause 1 Scope
st th
In the 1 sentence of the 6 paragraph change “450” into “500”.
2 Modification to 4.3.1.1 Production tolerances
Change the numbering of the second subclause numbered “4.3.1.1.1” into “4.3.1.1.2” and the numbering of
subclause “4.3.1.1.2” into “4.3.1.1.3”.
3 Modification to 4.3.1.1.2 Tolerances for concrete cover
In point 4.3.1.1.2 (now 4.3.1.1.3) introduce the sentence “The maximum deviation for concrete cover shall be
∆c=-10 mm. A more stringent tolerance can be declared by the manufacturer”.
4 Modification to 4.3.1.2.2 Minimum concrete cover and axis distances of
prestressing steel
Replace ” - when the nominal centre to centre distance of the strands ≥ 3 Ø : cmin = 1,5 Ø ;
- when the nominal centre to centre distance of the strands < 2,5 Ø : cmin = 2,5 Ø ;
- cmin may be derived by linear interpolation between the values calculated in a) and b);
Where
Ø is the strand or wire diameter, in millimetres (in the case of different diameters in a strand, the average
value shall be used for Ø).
For ribbed wires, the concrete cover shall be increased with 1 Ø.”
with:
a) “when the nominal centre to centre distance of the strands is ≥ 3 φ: c = 1,5 φ;
min
b) when the nominal centre to centre distance of the strands is < 2,5 φ: c = 2,5 φ;
min
where φ is the strand or wire diameter, in millimetres (in the case of different diameters, the average value
shall be used for φ).
For intermediate centre to centre distance, c may be derived by linear interpolation between the values
min
defined in a) and b).
For ribbed wires, the concrete cover shall be increased by 1 φ.”
5 Modification to 4.3.3.2.1 Resistance to splitting for prestressed hollow core slabs
In the title of 4.3.3.2.1 and in the rest of the text of 4.3.3.2.1, replace five times “splitting” with “spalling”.
3
---------------------- Page: 4 ----------------------
EN 1168:2005/prA1:2007 (E)
6 Modification to 4.3.3.2.2.1 General
Change the title "General" into "Shear capacity"
Add the following text after the title (before the existing statement):
“For hollow-core slabs without shear reinforcement, the shear resistance of the regions cracked by bending
shall be calculated using expressions (6.2a) and (6.2b) of EN 1992-1-1:2004.
For prestressed single span hollow-core slabs without shear reinforcement, the shear resistance of the
regions uncracked by bending (where the flexural tensile stress is smaller than f /γ ), the shear
ctk0,05 c
resistance should be calculated with the following expression:
Ib (y)
2
w
V = ()f + σ (y)f −τ (y)
Rdc ctd cp ctd cp
S (y)
c
where
n
1 (Y − y) M
c Ed
σ (y) = + ⋅P (l ) + ⋅()Y − y
cp ∑ t x c
A I I
t =1
n
1 A (y) S (y) ⋅(Y −Yp ) dP (l )
c c c t t x
τ (y) = ⋅ − +Cp (y) ⋅
cp ∑ t
b (y) A I d
w x
t =1
This expression shall be applied with reference to the critical points of a straight line of failure rising from the
edge of the support with an angle β = 35° with respect to the horizontal axis. The critical point is the point on
the quoted line where the result of the expression of V is the lowest.
Rd,c
The definition of symbols is given here below:
I is the second moment of area of the cross section
b (γ) web width at the critical point
w
γ is the height of the centroidal axis
c
S (γ) is the first moment of the area above height y and about the centroidal axis
c
γ is the height of the critical point on the line of failure
l is the distance of the considered point on the line of failure from the starting point of the transmission
x
length (= x)
σ (γ) is the concrete compressive stress at the height y and distance l
cp x
n is the number of tendon layers
A is the area of the cross-section
P (l ) is the prestressing force in the considered tendon at distance l . The transfer of prestress shall be
t x x
taken into account according to 8.10.2.2 of EN 1992-1-1:2004
M is the bending moment due to the vertical load, for this expression the bending moment may be
Ed
ignored
4
---------------------- Page: 5 ----------------------
EN 1168:2005/prA1:2007 (E)
M = 0
Ed
τ (γ) is the concrete shear stress due to transmission of prestress at height y and distance l
cp x
A (γ) is the area above height γ
c
Cp (γ) is a factor taking into account the position of the considered tendon layer
t
Cp = -1 when γ ≤ γ p
t t
Cp = 0 when γ > γ p
t t
γp is the height of the position of considered tendon layer
t
As an alternative to the above expression, the following simplified expression may be applied:
Ib
w 2
V = ϕ ()f + βα σ f
Rdc ctd l cp ctd
S
where
I/S is the second over first moment of area (= z lever arm);
α = l / l is the degree of prestressing transmission (α ≤ 1,0);
ℓ
x pt2 I
l is the distance of the considered section from the starting point of transmission length;
x
l upper value of transmission length (see eq. (8.18) of EN 1992-1-1:2004);
pt2
σ = N /A is the full concrete compressive stress at the centroidal axis;
cp Ed
f = f /γ is the design value of tensile strength of concrete;
ctd ctk0,05 c
ϕ = 0,8 reducing factor;
β = 0,9 reducing factor referred to transmission length.
For hollow-core slabs deeper than 450 mm the shear strength, both for regions cracked or uncracked by
bending, shall be reduced by 0,9 with respect to the equations quoted above.”
7 Modification to 4.3.3.2.2.2 Shear capacity – Torsion capacity
Change the title into "Shear with torsion capacity".
8 Modification to 4.3.3.2.3 Shear capacity of the longitudinal joints
After “∑h is the sum of the smallest thicknesses of the upper and lower flange and the scaled thickness of the
f
topping (see Figure 4)”, add the following sentence: “where this scaled thickness is the nominal thickness of the
topping multiplied by the ratio between the tensile strength of the topping and the tensile strength of the
slabs”.
5
---------------------- Page: 6 ----------------------
EN 1168:2005/prA1:2007 (E)
9 Modification to 4.3.6 Thermal properties
In the explanation of R change “contact” into “surface”.
c
10 Modification to 5.2.1.1 Procedure
In indent d) change “4.3.1.1.2a)” into “4.3.1.1.1a)” and in indent e) change “4.3.1.1.2b)” into “4.3.1.1.1b)”.
11 Modification to Annex A - Table A.3
th
In item 1, 4 column (Purpose) change “shear resistance” into “failure”.
12 Modification to Annex B - Figure B.1
Change the lower dimension of Figure B.1a) as follows:
Dimensions in millimetres
a) Joint with a tie bar b) Trapezial groove c) Semicircular groove
Key
d = Largest nominal maximum aggregate size of the mortar of the joint
g
Figure B.1 — Typical shapes of longitudinal joints
6
---------------------- Page: 7 ----------------------
EN 1168:2005/prA1:2007 (E)
13 Modification to Annex C - Figure C.4
In Figure C.4c) and d) show the position of the load as follows:
a) Point load in centre b) Point load between c) Linear load in ce
...