Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 188

Tests [2.54] show that when placed below the heads of the studs, the mesh
can increase the shear resistance of the studs. In practice, the control of its
level is poor and its detailing is not related to that of the shear connection.
Johnson and Yuan [ 3.7-3.9 ] considered the results of 269 push-off tests in a
study of existing design rules for the static shear resistance of stud connectors
in profiled steel sheeting. It was found [ 3.9 ] that test data were scarce for the
influence of the thickness of the profiled sheeting ( t ) and of lightweight
aggregate and for the influence of the position of the studs in each trough,
values of ( b o ) less than (2 h p ) and parallel sheeting. Therefore, the authors
reported the results for 34 push-off tests and identified seven distinct modes
of failure. The design rules for the static shear resistance of stud connectors in
profiled sheeting were studied, and it is found that they are limited in the case
of studs placed off-center in the steel troughs. Developed equations based on
theoretical models were obtained for the observed modes of failure. The
modes are shown to give good performance when compared with reported
test results.
(c) Composite beams with prestressed hollow core concrete slabs
Design equations developed for determining the capacity of the connec-
tors in a composite beam consisting of prestressed hollow-cored concrete
slabs were detailed in Lam et al. [2.61]. Twelve full-scale push-off tests were
carried out to study the effects of the size of the gap between the ends of the
precast slabs, the amount of tie steel placed transversely across the joint, and
the strength of concrete in-fill on the capacity of the shear stud. The follow-
ing design equation, modified from EC4 [2.37], “Equation (

) ,” was
given and there was no modification in Equation ( 3.77 ) as the strength of
the shear stud is thought not to be influenced by the precast construction:

3.78

p

of cp E cp 29 abed 2 0 :

P Rd ¼ ð 3 : 84 Þ

g v

where b is a factor that takes into account the gap width ( g ) in millimeters
(see Figure 2.17) and is given as 0.5( g /70+1) 1.0 and g 30 mm, e is a

factor that takes into account the diameter ( f ) of transverse high tensile steel
(grade 460) and is given by 0.5( f /20+1) 1.0 and f 8 mm, o is the
transverse joint factor ¼ 0.5( o /600+1), o is the width of hollow core con-
crete units, f cp is the average concrete cylinder strength ¼ 0.8 average cube
strength of the in situ and prestressed concrete, and E cp is the average value of
elastic modulus of the in situ and precast concrete. All other terms are as for
Equation (3.78) .

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