4.1 S TEEL -C ONCRETE C OMPOSITES
4.1.3 Slabs
Composite floor slabs are widely used in multi-storey buildings all over the world. Examples of different composite slabs are shown in Fig. 4. This construction consists of a thin steel sheet which serves as shuttering in the production phase and tension reinforcement in the final structure.
This way of producing slabs is time efficient due to no need of temporary shuttering in the construction phase. It also makes it possible to build thin structures compared to the obtained capacity. However, a numerous number of supports are needed in the building phase due to the poor flexural tensile capacity of the steel plates alone before the cured concrete can take
4. Hybrid Concrete Structures
10
compressive
system must be supported on every 1500
Being able to reduce or eliminate the need for such supports could reduce the In order to
embossed with projections repeated indefinitely or corrugated in such a way that connection corrosion. This is the main reason why pure concrete structures often can compete with steel concrete composites when
must be supported on every 1500
Being able to reduce or eliminate the need for such supports could reduce the In order to obtain full shear connection
embossed with projections repeated indefinitely or corrugated in such a way that connection is obtained corrosion. This is the main reason why pure concrete structures often can compete with steel
rete composites when
thin steel-concrete composite slabs are more construction phase, concrete hybrid product infrastructure applications
thin steel plate - concrete slabs described in S replaced by an FRP structure.
4. Hybrid Concrete Structures
. According to the must be supported on every 1500
Being able to reduce or eliminate the need for such supports could reduce the full shear connection
embossed with projections repeated indefinitely or corrugated in such a way that is obtained [8]. This is shown in
steel plate-concrete composites can be found in Eu corrosion. This is the main reason why pure concrete structures often can compete with steel
rete composites when such
concrete composite slabs are more
, compared to a hollow core deck or a combination of structural precast concrete formwork and in-situ concr
corrugated plate which in many cases s where a visual steel plate
Polymer-Concrete Composites
olymer (FRP
product on the market. It infrastructure applications in North America
concrete slabs described in S
replaced by an FRP structure. Example of FRP ribbed planks are shown in According to the thin
must be supported on every 1500 mm
Being able to reduce or eliminate the need for such supports could reduce the full shear connection between the steel and concrete, the sheets embossed with projections repeated indefinitely or corrugated in such a way that
This is shown in corrosion. This is the main reason why pure concrete structures often can compete with steel
such serviceability concrete composite slabs are more
compared to a hollow core deck or a combination of structural precast situ concrete. Anothe
corrugated plate which in many cases will be visible in the ceiling. A lowered ceiling will be a visual steel plate is not acceptable
Concrete Composites
(FRP) ribbed planks on the market. It in North America concrete slabs described in S
Example of FRP ribbed planks are shown in thin steel sheet
mm in the buildi
Being able to reduce or eliminate the need for such supports could reduce the between the steel and concrete, the sheets embossed with projections repeated indefinitely or corrugated in such a way that
This is shown in Fig. 4, in the top and bottom respectively.
concrete composites can be found in Eu
l sheet - concrete composites
Challenges Connected To Steel-Concrete Composites
concrete composites is the unprote
tension side. Steel is well known for its severe shortage when it comes to fire resistance and corrosion. This is the main reason why pure concrete structures often can compete with steel
serviceability aspects are taken into account.
concrete composite slabs are more dependent of temporary supports in concrete slabs described in Section 4.1.3
Example of FRP ribbed planks are shown in steel sheet producer Plannja
in the building phase for a 240 Being able to reduce or eliminate the need for such supports could reduce the
between the steel and concrete, the sheets embossed with projections repeated indefinitely or corrugated in such a way that
in the top and bottom respectively.
concrete composites can be found in Eu
concrete composites [3]
Concrete Composites
concrete composites is the unprote
tension side. Steel is well known for its severe shortage when it comes to fire resistance and corrosion. This is the main reason why pure concrete structures often can compete with steel
aspects are taken into account.
dependent of temporary supports in compared to a hollow core deck or a combination of structural precast
r esthetic issue with this kind of slabs is the will be visible in the ceiling. A lowered ceiling will be
is not acceptable.
the most common commercial is widely used in
The concept is in many ways
4.1.3, except that the thin steel plate is Example of FRP ribbed planks are shown in
producer Plannja, their
g phase for a 240 mm thick slab Being able to reduce or eliminate the need for such supports could reduce the production costs.
between the steel and concrete, the sheets embossed with projections repeated indefinitely or corrugated in such a way that
in the top and bottom respectively.
concrete composites can be found in Eurocode 4, part 1
[3].
Concrete Composites
concrete composites is the unprotected steel part on the tension side. Steel is well known for its severe shortage when it comes to fire resistance and corrosion. This is the main reason why pure concrete structures often can compete with steel
aspects are taken into account.
dependent of temporary supports in compared to a hollow core deck or a combination of structural precast
r esthetic issue with this kind of slabs is the will be visible in the ceiling. A lowered ceiling will be
the most common commercial in bridge decks The concept is in many ways
except that the thin steel plate is Example of FRP ribbed planks are shown in Fig. 5.
their standard slab mm thick slab
roduction costs.
between the steel and concrete, the sheets are usually embossed with projections repeated indefinitely or corrugated in such a way that shear in the top and bottom respectively. Design
, part 1-1 [6]
cted steel part on the tension side. Steel is well known for its severe shortage when it comes to fire resistance and corrosion. This is the main reason why pure concrete structures often can compete with steel
dependent of temporary supports in compared to a hollow core deck or a combination of structural precast
r esthetic issue with this kind of slabs is the will be visible in the ceiling. A lowered ceiling will be
the most common commercial polymer bridge decks and other corrosion. This is the main reason why pure concrete structures often can compete with
steel-dependent of temporary supports in the
11 Fig. 5: Typical FRP ribbed planks [10].
Advantages with the ribbed FRB are the relatively high flexural stiffness of the plank with the ribs and the low weight compared to its strength. In the construction phase, this system requires less supports compared to the thin steel plate system due to its relatively high flexural stiffness. The planks can be delivered in any color and are versatile since they easily can be produced in arbitrary shapes and with different surface structure. Shear connection is here obtained by the shape of the polymer ribs connecting to the concrete. Fig. 6 shows a FRP plank with a concrete slab.
Fig. 6: FRP ribbed plank with concrete slab [11].
4.3 Concrete-Concrete Composites
Concrete-concrete composites can be subdivided into structures with different concrete over the structure cross section, combination of precast and in-situ concrete and combinations of the two.
4.3.1 Precast Concrete Formwork with In-situ Concrete Top Cast
A very common slab solution is a combination of precast concrete formwork and in-situ concrete. In Norway this kind of system is delivered by Con-Form and Unicon among others.
This system is based on precast slabs with lattice girder reinforcement which acts like formwork in the construction phase. A typical example of precast concrete formwork is shown in Fig. 7.
4. Hybrid Concrete Structures
12
The main tension
lattice girder reinforcement The girder
of the girder the structural reinfo layer is
cast has cured.
Since the top steel reinforcement only can take small pressure forces due to its dimension and slenderness, the concrete formwork requires
phase, unless the s during construction.
floor props
4. Hybrid Concrete Structures
The main tension and minimum transversal lattice girder reinforcement
The girder also stabilizes the slab during the construction phase and the top steel reinforcement of the girder takes the
the structural reinfo
layer is cast over the whole concrete formwork, turning it to a monolithic slab after the final cast has cured.
Fig.
Since the top steel reinforcement only can take small pressure forces due to its dimension and slenderness, the concrete formwork requires
phase, unless the s during construction.
floor props placed on the underlying deck. The 4. Hybrid Concrete Structures
Fig. 7: Typical
and minimum transversal lattice girder reinforcement acts like shear connect
also stabilizes the slab during the construction phase and the top steel reinforcement takes the compression
the structural reinforcement is put in place after the
over the whole concrete formwork, turning it to a monolithic slab after the final
Fig. 8: Installation of
Since the top steel reinforcement only can take small pressure forces due to its dimension and slenderness, the concrete formwork requires
phase, unless the spans are short. A typical 7m Con during construction. This is illustrated in
placed on the underlying deck. The : Typical precast
and minimum transversal acts like shear connect
also stabilizes the slab during the construction phase and the top steel reinforcement compression forces alone through the construction phase.
rcement is put in place after the
over the whole concrete formwork, turning it to a monolithic slab after the final
: Installation of precast
Since the top steel reinforcement only can take small pressure forces due to its dimension and slenderness, the concrete formwork requires
pans are short. A typical 7m Con This is illustrated in Fig.
placed on the underlying deck. The
precast concrete formwork
and minimum transversal reinforcement is located in the acts like shear connectors between the
also stabilizes the slab during the construction phase and the top steel reinforcement forces alone through the construction phase.
rcement is put in place after the precast
over the whole concrete formwork, turning it to a monolithic slab after the final
precast concrete formwork in Sweden
Since the top steel reinforcement only can take small pressure forces due to its dimension and slenderness, the concrete formwork requires temporary
pans are short. A typical 7m
also stabilizes the slab during the construction phase and the top steel reinforcement forces alone through the construction phase.
precast slabs are mounted. Finally the top over the whole concrete formwork, turning it to a monolithic slab after the final
formwork in Sweden
Since the top steel reinforcement only can take small pressure forces due to its dimension and temporary supports t
-form precast
. The support beams are usually supported by work with the temporary supports is a time
[12].
reinforcement is located in the precast ors between the precast and in
also stabilizes the slab during the construction phase and the top steel reinforcement forces alone through the construction phase.
slabs are mounted. Finally the top over the whole concrete formwork, turning it to a monolithic slab after the final
formwork in Sweden [13].
Since the top steel reinforcement only can take small pressure forces due to its dimension and supports through the construction cast slab requires 3 supports . The support beams are usually supported by work with the temporary supports is a time precast slab. The and in-situ layer.
also stabilizes the slab during the construction phase and the top steel reinforcement forces alone through the construction phase. The rest of
slabs are mounted. Finally the top over the whole concrete formwork, turning it to a monolithic slab after the final
Since the top steel reinforcement only can take small pressure forces due to its dimension and hrough the construction slab requires 3 supports . The support beams are usually supported by work with the temporary supports is a time slab. The situ layer.
also stabilizes the slab during the construction phase and the top steel reinforcement The rest of slabs are mounted. Finally the top over the whole concrete formwork, turning it to a monolithic slab after the final
Since the top steel reinforcement only can take small pressure forces due to its dimension and hrough the construction slab requires 3 supports . The support beams are usually supported by work with the temporary supports is a time
demanding job and solutions where the completely would save a lot of money.
Precast completely would save a lot of money.
Precast concrete formwork
up to 8.1m. The elements are purely o extra structural cast
a level cast on the very top behavior of the structure.
as shown in Fig.
Limitation in this system is the relatively low load capacit height of 250 mm
core slab, with height of 220 mm and 6 m span, which demanding job and solutions where the
completely would save a lot of money.
concrete formwork o extra structural cast is needed on the a level cast on the very top
behavior of the structure. Steel reinforcement is used both Fig. 9.
Fig. 9
in this system is the relatively low load capacit height of 250 mm can only
, with height of 220 mm and 6 m span, which demanding job and solutions where the
completely would save a lot of money.
concrete formwork is usually delivered in widths up to 2.4m and spans up to 7.2 pans up to 12m
s of slabs can be desi usually related to serviceability aspects
ECA Byggeplank
k is delivered as construction elements The elements are purely precast
is needed on the
a level cast on the very top which will increase the capacity somewhat, due to monolithic Steel reinforcement is used both
9: Principles of
in this system is the relatively low load capacit can only carry a little over 5 kN/m , with height of 220 mm and 6 m span, which
demanding job and solutions where the amount of supports could be reduce
y delivered in widths up to 2.4m and spans up to 7.2 pans up to 12m can be delivered
be designed to r
of crack width and maximum displacement.
Byggeplank
as construction elements
precast and are lifted into place at the construction site.
is needed on the LECA Byggeplank. However, it is not uncommon to do which will increase the capacity somewhat, due to monolithic Steel reinforcement is used both
: Principles of Weber's Leca Byggeplank 250T
in this system is the relatively low load capacit a little over 5 kN/m , with height of 220 mm and 6 m span, which
amount of supports could be reduce
y delivered in widths up to 2.4m and spans up to 7.2 delivered when
ed to resist very large loads, with of crack width and maximum displacement.
as construction elements with
and are lifted into place at the construction site.
Byggeplank. However, it is not uncommon to do which will increase the capacity somewhat, due to monolithic Steel reinforcement is used both in the tensi
's Leca Byggeplank 250T
in this system is the relatively low load capacity. As an example a little over 5 kN/m2 [15]. This can be , with height of 220 mm and 6 m span, which can carry up
amount of supports could be reduce
y delivered in widths up to 2.4m and spans up to 7.2 when pre stressed
esist very large loads, with of crack width and maximum displacement.
with widths of 0.6m
and are lifted into place at the construction site.
Byggeplank. However, it is not uncommon to do which will increase the capacity somewhat, due to monolithic
the tensile and
's Leca Byggeplank 250T [15].
. As an example the
. This can be compared to a hollow can carry up to 18kN/m
amount of supports could be reduced partly or
y delivered in widths up to 2.4m and spans up to 7.2
pre stressed reinforcement is esist very large loads, with limitations of crack width and maximum displacement.
widths of 0.6m and in lengths and are lifted into place at the construction site.
Byggeplank. However, it is not uncommon to do which will increase the capacity somewhat, due to monolithic
y delivered in widths up to 2.4m and spans up to 7.2m with reinforcement is imitations
and in lengths and are lifted into place at the construction site.
Byggeplank. However, it is not uncommon to do which will increase the capacity somewhat, due to monolithic compressive zone
6 m element with compared to a hollow
5
5.1
The Concrete Sandwich Slab (CSS)
new concept which is based on ideas from existing products like the
The cross sectional principles of the CSS concept are shown in
on the hybrid structure idea of different materials in high stress versus Confer the principles of the lattice girder in Section
If the load case would be such additional reinforcement in the
construction with monolithic behavior over supports.
5 Concrete Sandwich Slab
5.1 The Concept
The Concrete Sandwich Slab (CSS)
new concept which is based on ideas from existing products like the combinations of pre
solutions. The concept is developed purely by the authors of this report.
The CSS is meant to be a formwork. This produ
environments due to its surface
The cross sectional principles of the CSS concept are shown in
on the hybrid structure idea of different materials in high stress versus general load case in which the tensi
compressive to the top, norma
bottom and top respectively. In the low stress zone, typically in the cross sectional middle, a LWAC is used to reduce the structural weight. In o
different layers, shear connectors are placed through the three layers as shown in Confer the principles of the lattice girder in Section
f the load case would be such additional reinforcement in the
construction with monolithic behavior over supports.
Concrete Sandwich Slab
Concept
The Concrete Sandwich Slab (CSS)
new concept which is based on ideas from existing products like the combinations of precast concrete formwork and in
The concept is developed purely by the authors of this report.
The CSS is meant to be a
This product will be able to environments due to its surface
The cross sectional principles of the CSS concept are shown in
on the hybrid structure idea of different materials in high stress versus load case in which the tensi
to the top, norma
bottom and top respectively. In the low stress zone, typically in the cross sectional middle, a is used to reduce the structural weight. In o
different layers, shear connectors are placed through the three layers as shown in
different layers, shear connectors are placed through the three layers as shown in