Civil Engineering Reference
In-Depth Information
structural steel: yield strength
f
y
=
f
yd
=
355 N/mm
2
(
γ
A
=
1.0)
profiled steel sheeting: yield strength
f
yp
=
f
yp,d
=
350 N/mm
2
(
γ
A
=
1.0)
reinforcement: yield strength
f
sk
=
500 N/mm
2
,
f
sd
=
435 N/mm
2
(
γ
S
=
1.15)
welded fabric: yield strength
f
sk
=
500 N/mm
2
,
f
sd
=
435 N/mm
2
(
γ
S
=
1.15)
shear connectors; 19-mm headed studs 100 mm high;
ultimate strength
f
u
=
500 N/mm
2
,
f
ud
=
400 N/mm
2
(
γ
V
=
1.25)
210 kN/mm
2
. In design
of beams and slabs, the value for
reinforcement is assumed, for simplicity,
also to be 210 kN/mm
2
; but the more accurate value,
E
s
The elastic modulus for structural steel is
E
a
=
=
200 kN/mm
2
is
used in column design.
Resistance of the shear connectors
The design shear resistance is given by Equation 2.15 and is
P
Rd
=
0.29
×
19
2
(25
×
20 700)
0.5
/(1.25
×
1000)
=
60.2 kN
(3.1)
Equation 2.14 gives the higher value 91 kN, and so does not apply.
Permanent actions
From Table 1.4, the unit weights of the concretes, including reinforcement,
are:
for LC25/28, 19.5 kN/m
3
;
for C25/30, 25.0 kN/m
3
For design of formwork, each value is increased by 1 kN/m
3
(from EN
1991-1-1) to allow for the higher moisture content of fresh concrete.
The unit weight of structural steel is taken as 77 kN/m
3
.
The characteristic weight of floor and ceiling finishes is taken as 1.3 kN/m
2
.
Variable actions
The floors to be designed are assumed to be in category C3 of EN 1991-
1-1: [13] 'Areas where people may congregate, without obstacles for moving
people' (e.g., exhibition rooms, etc.). The characteristic loadings are:
q
k
=
5.0 kN/m
2
on the whole floor area or any part of it
(3.2)
or
Q
k
=
4.0 kN on any area 50 mm square
(3.3)
The load
q
k
is high for a building not intended for storage or industrial
use. Its use here enables many aspects of design to be illustrated. For
