The by high density polyethylene hollow 8 Conclusion

The result identified that 1m3 of concrete replaced
by high density polyethylene hollow

8    Conclusion

Life span of buildings is

Changes are much less

Buildings are more

Subsequent work
(installations) are simplified

Transportation costs are
heavily reduced

Manual mounting of
reinforcement meshes on the building site is avoided

Savings in materials
(slabs, pillars, fundaments) are substantial (up to 50%)

7.6 Economic

Transportation of materials
is reduced considerably – lower costs and environmental improvement

7.5 Transportation

•   Less emission –
exhaust gases from production and transport, especially CO2.

•   Less energy
consumption – both in production, transport and carrying out.

•   Savings in
materials – up to 50 % – 1 kg of plastic replaces more   than 100 kg of concrete.

7.4 Environmental Improvement

•   Moisture –
Condensation-safe construction.

•   Earthquake –
Safety will benefit significantly alone from the weight reduction.

•   Fire – Fireproof

7.3 Safety

•   Less storage

•   Easier and more
simple erection

•   Less work in situ
; employment of unskilled labour

•   Higher quality
through automated production of prefabricated units

7.2 Production & Carrying Out

•  No beams or ribs under the ceiling.

•  Fewer columns

•  Larger span

•  Increased strength

•  Reduced weight

7.1 Superior

7    Advantages

Table 3: Comparison
Between Bubbledeck And Conventional Concrete Slab




% of concrete
replaced  = 27%                         

                                      =26.9% ? 27%

Quantity of
concrete saved in model slab is     
8.0748 -5.90=2.1698m3                                                     % of concrete replaced           = (2.1698/8.0748)*100

Concrete saving is
calculated by comparing the equation = (2)-(1)

6.3 Comparison                                 

Amount of concrete
in convectional slab is 
2.340+1.944+3.7908=8.0748m3…. (2)

Slab portion is
2(3.9*2.7*0.18) =3.7908m3

Beam in
y-direction is 4(2.7*03*0.45)   =1.944m3

Beam in
x-direction is 3(4.5*0.3*0.450) =2.430m3

6.2 Convectional slab

Amount of concrete
in bubble deck slab is       8.505-2.6
=5.905 m³…. (1)

Amount of concrete
replaced by bubbles is  (?*4*0.270^3) /24*250        =2.6m³

Size of model slab
= 6.3*4.5*0.3=8.505 m³

6.1 Bubble
Deck Slab

6    Cost

Figure 20: Bubble Deck Model

Fig 20 shows the model of recycled high
density polyethylene hollow sphere bubble deck slab 

Figure 19: Provision of Top Reinforcement Meshes

The placing of top reinforcement on the
structure and is shown in fig 19


Figure 18: Arrangements of Recycled HDPE Hollow Sphere



The recycled balls are placed on the top of
the bottom reinforcement with clear cover and is shown in fig 18

Figure 17: Column Reinforcement

The column reinforcements are provided in the
structure and is shown in the fig 17

Figure 16: Slab Model Bottom Reinforcement


The model is done by using scaled dimensions
as shown above and bottom reinforcement also shown in fig 16





Model Dimension


Lx =4500
LY  =6300







Table 2: Model Dimensions

initial step is making column and slabs using acrylic sheets with 3mm
thickness. The dimensions of column and slab are shown in Table 2.

5   Model Making


Figure 15: Section BB of Model

Fig 15 of section BB passes
through the slab and column portion. It represents the sectional view of slab
including column reinforcement details


Figure 14: Section AA of Model

          Fig 14 of section
AA passes through the slab portion only. It represents the sectional view of
the slab including diagonal girder and bubbles.

4.2 Cross
Section of Bubble Deck Model

Figure 13: Plan View of Model

The fig 13 of
plan view shows the arrangement of bottom reinforcement meshes with bubbles,
column reinforcements and diagonal girder edge positioning 

4.1 Plan of Bubble Deck Model

4    Drawings

Figure 12: Concrete Slab Surface Finishing

Finally concrete surface finished with finishing tools. There is no
further work required, the slab is complete unless requirement for exposed
soffit. The surface finishing is shown in fig 12

Figure 11:  Concrete Vibration


After concreting, vibration is provided for bottom and top concrete
setting. Removing air content from the slab. Because of the little space
between spheres, it is used a thin vibrator. The surface of the poured concrete
in leveled with a metallic profile. The vibration process is shown in fig 11

Figure 10: Slab Concreting

Concrete provided over the
slab by pumping. Concrete is poured in between the ball gaps. Immediately after
pouring, the surface of the concrete is cleaned with under pressure water to
remove the dust and to moister the surface. Especially in times of high
temperatures the surface of the precast element is kept wet to ensure the
needed adherence. When the geometry of the connections of the partially
prefabricated elements are not rigorously followed according to the design the
concreting is adjusted with fluid mortar or with a thin layer of silicon pumped
at the bottom part of the connection. In order to adjust the connections one
should never use expanded foams that may lead to reducing the thickness of the
concrete layer and therefore to reducing the durability of the reinforcement
and the fire resistance. Self-compacting concrete can be poured into forms,
flow around congested areas of reinforcement and into tight sections, allow air
to escape and resist segregation, without the standard consolidation efforts.
The concreting process is shown in fig 10.

3.6 Concreting

Figure 9: Fixing Partially Manufactured
Bubble Deck Slab

is the process of positioning and joining the semi manufactured slab.  After fixing, concrete is provided over the
slab. The following fig 9 shows fixing partially manufactured bubble deck slab.

3.5 Fixing of slab components

Figure 8: Transportation of Precast Bubble Deck Slab

Partial precast concrete
elements. They have the bottom part made of precast concrete and the
connections between elements and the over concreting are cast in place. The
figure 7 and 8 shows that transportation of partially manufactured deck slabs.

3.4.2 Version B

Figure 7: Transportation of Precast Bubble Deck Slab

           Reinforcement modules in which the
spheres are placed to produce the gaps and if the case, tubes for HVAC
(electrical, heating, etc.), modules that are to be placed in formworks. The
plates are cast in place.

3.4.1Version A

Semi manufactured slab
transported through truck or crane. The BubbleDeck slab gaps elements can be
delivered in the following versions:

3.4 Transportation


Figure 6: Provision of Top Reinforcement

•       Placing of the
polystyrene spheres between the meshes according to plans. The fig 6 shows the
provision of top reinforcement as below

•       Fixing small
boxes or pieces of polystyrene on reinforcement meshes for marking the position
of the walls or the   columns and

•       Placing the
pipelines, cables and element of electric fittings if the case

•       Making the
reinforcement meshes.

After placing the balls, top reinforcement meshes are provided on the
top of the sphere. It positioning the ball and also act as a cover for the
balls. The
two mashes are connected after placing the spheres into places in order to
forma rigid shell. In order to achieve the reinforcement modules for BubbleDeck
slabs with gaps. The following operations must take place:

3.4 Provision of
Top Reinforcement

 Figure 5: Location of Hollow

The hollow sphere is placed
in between the reinforcement instead of concrete. Bottom reinforcement and
diagonal girders keep the bubbles in position. Diagonal girders fixed between
the top and bottom reinforcement. During the final positioning of the slab elements
it is checked if the displaying of the spheres is according to the plans. Also
it is checked the reinforcement in the over concreting areas. The transversal
reinforcement bars must be embedded in the adjacent slab elements. Partially
precast made elements are designed and realized so that the building
configuration is maintained. They are delivered with pieces of polystyrene
included that mark the position of the walls or the columns. The location of
sphere is shown in fig 5

Location of Hollow