INTRODUCTION AND COMPARISON OF VARIOUS FLOORING SYSTEMS · Introduction to various flooring systems...
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STRUCTURAL FLOORING SYSTEMS INTRODUCTION AND COMPARISON OF VARIOUS FLOORING SYSTEMS
Transcript of INTRODUCTION AND COMPARISON OF VARIOUS FLOORING SYSTEMS · Introduction to various flooring systems...
STRUCTURAL FLOORING SYSTEMS INTRODUCTION AND COMPARISON OF VARIOUS
FLOORING SYSTEMS
STRUCTURAL FLOORING SYSTEMS
Introduction to various flooring systems
Advantages and Disadvantages
Structural depth
Cost comparison
OBJECTIVES
STRUCTURAL FLOORING SYSTEMS
Conventional RC slab and beam.
Post-tensioned slab.
Pre-cast slab.
Composite steel deck slab.
CLASSIFICATION
DROP BEAM AND SLAB
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
4 - 10 400 - 650 175 - 300 197 - 345
SECTION THROUGH BEAM
Advantages
Large openings can be accommodated in the slab elements.
Simpler reinforcement arrangement.
Inherent corrosion protection and fire resistance.
Traditional method of construction.
Simple method of construction.
Robust construction
BAND BEAM AND SLAB
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
4 - 10 300 - 550 175 - 300 197 - 345
SECTION THROUGH BEAM
Large openings can be accommodated in the slab
elements.
Shallow depth of beams provides flexibility in horizontal
service distribution.
Simpler reinforcement arrangement.
Inherent corrosion protection and fire resistance.
Traditional method of construction.
Simple method of construction.
Robust construction
Advantages
Disadvantages
Large openings cannot be accommodated easily on the beam
lines.
More complex formwork compared to flat slab systems.
FLAT SLAB
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
4 - 6 180 - 250 180 - 250 228 - 298
SECTION THROUGH SLAB
Advantages
Flat soffit.
Shallow depth.
False ceiling area can be minimised.
Flexibility in horizontal service distribution.
Minimal site coordination
Very simple formwork.
Inherent corrosion protection and fire resistance.
Simple method of construction.
Robust construction.
Disadvantages
Vertical risers need to be pre-planned.
Large openings near columns difficult to accommodate.
Heavier construction than slab and beam system.
Large amounts of reinforcements.
FLAT SLAB WITH DROP PANELS
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
6 - 8 350 - 490 200 - 280 239 - 309
SECTION THROUGH SLAB
Advantages
Shallow depth.
Minimal site coordination
Flexibility in horizontal service distribution.
Inherent corrosion protection and fire resistance.
Simple method of construction.
Robust construction.
Lighter construction compared to flat slab..
Disadvantages
Drop panel makes formwork more complex.
Vertical risers need to be pre-planned.
Large openings near columns difficult to accommodate.
Heavier construction than slab and beam system.
Large amounts of reinforcements.
RIB SLAB
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
6 - 12 400 - 500 275 - 500 248 - 357
L-SECTION THROUGH
RIB SLAB X-SECTION THROUGH
RIB SLAB
Advantages
Profile may be expressed architecturally.
Level rib and beam soffits.
Flexibility in horizontal service distribution.
Flexibility in vertical service distribution as large
openings can be accommodated in the slab elements
between ribs.
Lightweight construction.
Inherent corrosion protection and fire resistance.
Robust construction.
Traditional method of construction
Disadvantages
Higher formwork cost.
Large openings cannot be accommodated easily on the beam
lines.
Slower construction due to increased formwork.
Additional efforts to place reinforcements.
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
7 - 13 400 - 550 300 - 550 336 - 440
RIB SLAB WITH HOURDI BLOCKS
X-SECTION THROUGH
HOURDI SLAB L-SECTION THROUGH
HOURDI SLAB
Level rib and beam soffits.
Flexibility in horizontal service distribution.
Flexibility in vertical service distribution as large
openings can be accommodated in the slab elements
between ribs.
Lightweight construction.
Simplified formwork compared to rib slab.
Inherent corrosion protection and fire resistance.
Robust construction.
Traditional method of construction
Advantages
Large openings cannot be accommodated easily on the beam
lines.
Heavier compared to rib slab.
Additional efforts to place reinforcements.
Additional effort to place void formers.
Disadvantages
WAFFLE SLAB
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
7 - 13 400 - 650 275 - 500 300 - 456
X-SECTION THROUGH
WAFFLE SLAB
Advantages
Profile may be expressed architecturally.
Level rib and beam soffits.
Flexibility in horizontal service distribution.
Flexibility in vertical service distribution as large
openings can be accommodated in the slab elements
between ribs.
Lightweight construction.
Inherent corrosion protection and fire resistance.
Robust construction.
Traditional method of construction.
Disadvantages
Complex formwork required.
Higher formwork cost than rib slab.
Large openings cannot be accommodated easily on the beam
lines.
Slower construction due to increased formwork.
Difficult to prefabricate reinforcements.
POST-TENSIONED SLAB
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
6 - 12 180 - 360 180 - 360 216 - 410
SECTION THROUGH SLAB
Advantages
Shallow structural depth compared to solid slab.
False ceiling area can be minimised.
Flexibility for services.
Fastest in-situ concrete option.
Very simple formwork.
Lightly reinforced with simple reinforcement
arrangement.
Inherent corrosion protection and fire resistance.
Robust construction.
Disadvantages
Less flexible for future modifications.
Will require coordination with a specialist sub-contractor on
site.
Vertical risers need to be pre-planned.
Large openings near columns difficult to accommodate.
Possible hindrance to the advanced construction of shear
walls.
POST-TENSIONED SLAB WITH BAND BEAMS
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
7 - 12 315 - 525 180 - 300 217 - 333
SECTION THROUGH BAND BEAM
Advantages
Shallower slab thickness.
Lightly reinforced with simple reinforcement
arrangement.
Inherent corrosion protection and fire resistance.
Robust construction.
Disadvantages
Less flexibility for services due to the presence of band beams.
Less flexible for future modifications.
Vertical risers need to be pre-planned.
Large openings cannot be accommodated easily on the beam
lines.
Will require coordination with a specialist sub-contractor on site.
Possible hindrance to the advanced construction of shear walls.
POST-TENSIONED SLAB WITH DROP PANELS
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
7 - 13 350 - 650 180 - 340 222 - 398
SECTION THROUGH SLAB
Advantages
Shallower slab thickness.
Lightly reinforced with simple reinforcement
arrangement.
Inherent corrosion protection and fire resistance.
Robust construction.
Disadvantages
Drop panel makes formwork more complex.
Less flexibility for services due to the presence of drop panels.
Less flexible for future modifications.
Will require coordination with a specialist sub-contractor on site.
Possible hindrance to the advanced construction of shear walls.
Vertical risers need to be pre-planned.
Large openings near columns difficult to accommodate.
HOLLOW CORE SLAB
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
4 - 15 500 - 900 220 - 270 215 - 330
SECTION THROUGH HCS SECTION THROUGH BEAM
Advantages Reduced structural depth.
Flexibility for horizontal services in one direction.
Speed of construction as much of floor system is pre-
cast in factory.
No slab formwork.
No slab propping.
Lighter floor than the conventional construction.
Disadvantages Less suitable for irregular architectural plan forms.
A grid of beams deeper than slab is required.
Large openings more difficult to accommodate into the
slabs.
Horizontal service distribution more difficult in two directions.
Suspension of heavier service equipment requires co-
ordination.
As the pre-cast slab comes with a camber, levelling of the
slab needs attention.
Complications of placing the nibs on shear walls.
Limited number of pre-cast suppliers resulting in possible
cost fluctuations.
Requires more craneage.
EP SLAB
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
4 - 12 500 - 850 270 - 470 245 - 347
X-SECTION THROUGH EP SLAB L-SECTION THROUGH EP SLAB
Advantages
More suitable for irregular architectural plan forms than
hollow core slabs.
Reduced structural depth.
False ceiling area can be minimised.
Larger openings can be accommodated into the slabs.
Services can be run through void former in one direction.
Flexibility for horizontal services in one direction.
Speed of construction as much of floor system is pre-
cast in factory.
No slab formwork.
No slab propping.
Lighter floor than the conventional construction or hollow
core.
Disadvantages
Horizontal service distribution more difficult in two directions.
A grid of beams deeper than slab is required.
Suspension of heavier service equipments requires co-
ordination.
As the pre-cast slab comes with a camber, levelling of the
slab needs attention.
Complications of placing the nibs on shear walls.
Limited number of pre-cast suppliers resulting in possible cost
fluctuations.
Requires more craneage.
T – SECTION SLAB
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
9 - 16 750 - 900 535 - 785 344 - 420
X-SECTION THROUGH SLAB L-SECTION THROUGH SLAB
Advantages
Reduced structural depth.
Flexibility for horizontal services in both directions as
concealed nibs can be used to support the pre-cast slabs.
Flexibility in vertical service distribution as large openings
can be accommodated in the slab elements between ribs.
Smaller horizontal penetrations can be pre-cast in the ribs.
Speed of construction as much of floor system is pre-cast
in factory.
No slab formwork.
No slab propping.
Lighter floor than the conventional construction.
Disadvantages
Less suitable for irregular architectural plan forms.
Large openings more difficult to accommodate into the slabs.
Suspension of heavier service equipments requires co-
ordination.
As the pre-cast slab comes with a camber, levelling of the
slab needs attention.
Complications of placing the nibs on shear walls.
Limited number of pre-cast suppliers resulting in possible cost
fluctuations.
Requires more craneage.
COMPOSITE DECK SLAB ON STEEL BEAMS
Range of Span
(m)
Range of structural depth
(mm)
Range of slab
thickness (mm)
Range of cost
(Dhs./m2)
4 - 10 376 - 737 323 - 587 461 - 1093
SECTION THROUGH
SECONDARY BEAM
SECTION THROUGH
MAIN BEAM
Advantages
Flexibility in vertical service distribution as large openings can
be accommodated between the secondary steel beams.
Compatible with possible large span steel transfer structures.
Rapid construction.
No slab formwork.
No slab propping.
This is the lightest option resulting in smaller columns and
foundations
Disadvantages
Horizontal service distribution more difficult.
Greater floor depth compared to other systems.
Could require longer lead-time depending on availability of
steel sections locally.
The steel beams will require additional corrosion resistance
and fire protection.
Greater cost
Comparison of Slab systems
Spans of 4.0 m to 16.0 m are considered for analysis.
Beam spans are limited to 9.0 m.
A typical office floor loading of 3.5 kN/m2 super imposed dead
load and 4.0 kN/m2 live load is considered.
Cost of structural elements and fire proofing only are included
in the total cost.
Indirect costs are not included in the total cost.
Assumptions
COMPARISON OF SLAB TYPE Vs SPAN
A CHART OF SLAB TYPE Vs SPAN
4 5 6 7 8 9 10 11 12 13 14 15 16
T-Slab
Waffle
PT+BB
PT+DP
Rib+Hourdy
Rib
PT
Flat +DP
Hollow Core
EP Poly
Steel Deck
2w ay
1w ay
Flat Slab
SL
AB
TY
PE
SPAN (m)
COMPARISON OF SLAB THICKNESS Vs SPAN
THICKNESS OF THE SLAB Vs SPAN OF THE SLAB
Hollow Core
EP Poly
T SLAB
Steel Deck
2-Way
1-Way
Ribbed
WaffleRib+Hourdy
Flat Slab Flat+DP
PTPT+DP
PT+BB
100
200
300
400
500
600
700
800
4 5 6 7 8 9 10 11 12 13 14 15 16
SPAN OF THE SLAB (m)
TH
ICK
NE
SS
OF
TH
E S
LA
B (
mm
)
Hollow Core EP Poly T SLAB Steel Deck 2-Way 1-Way Ribbed
Waffle Rib+Hourdy Flat Slab Flat+DP PT PT+DP PT+BB
COMPARISON OF BEAM DEPTH Vs SPAN
DEPTH OF BEAMS Vs SPAN
Hollow Core
EP Poly
T SLAB
Steel Deck
2-Way
1-Way
Ribbed
Waffl
e
Rib+Hourdy
Flat Slab
PT
PT+BB
150
250
350
450
550
650
750
850
950
4 5 6 7 8 9 10 11 12 13 14 15 16
SPAN OF THE SLAB (m)
TH
ICK
NE
SS
OF
TH
E B
EA
M (
mm
)
Hollow Core EP Poly T SLAB Steel Deck 2-Way 1-Way Ribbed
Waffle Rib+Hourdy Flat Slab Flat+DP PT PT+BB
COMPARISON OF COST OF FLOOR SYSTEM Vs. SPAN
SPAN OF THE SLAB Vs COST PER m2
Hollow Core
EP Poly
T SLAB
Steel D
eck
2-Way1-Way
Ribbed
Waffle
Rib+Hourdy
Flat SlabFlat+DP
PT
PT+DP
PT+BB
150
250
350
450
550
650
750
850
4 5 6 7 8 9 10 11 12 13 14 15 16
SPAN OF THE SLAB
CO
ST
PE
R m2
Hollow Core EP Poly T SLAB Steel Deck 2-Way 1-Way Ribbed
Waffle Rib+Hourdy Flat Slab Flat+DP PT PT+DP PT+BB
SUMMARY OF SLAB OPTIONS
Slab Type Range of Span
(m)
Range of structural
depth (mm)
Range of slab
thickness
(mm)
Range of cost
(Dhs./m2)
Conventional 1-way slab 4 - 10 400 - 650 175 - 300 197 - 345
Conventional 2-way slab 4 - 10 400 - 550 175 - 300 206 - 314
Flat slab 4 - 6 180 - 250 180 - 250 228 - 298
Flat slab with drop panel 6 - 8 350 - 490 200 - 280 239 - 309
Rib Slab 6 - 12 400 - 500 275 - 500 248 - 357
Rib slab with filler block 7 - 13 400 - 550 300 - 550 336 - 440
Two-way Rib Slab 7 - 13 400 - 650 275 - 500 300 - 456
Post-Tensioned Slab 6 - 12 180 - 360 180 - 360 216 - 410
Post-Tensioned slab and Drop panel 7 - 11 315 - 525 180 - 300 217 - 333
Post-Tensioned slab and band beam 7 - 13 350 - 650 180 - 340 222 - 398
Hollow core slab 4 - 15 500 - 900 220 - 570 215 - 330
Poly slab (EP) 4 - 12 500 - 850 270 - 470 245 - 347
T-Section slab 9 - 16 750 - 900 535 - 785 344 - 420
Composite Deck slabs on steel beams 4 - 10 376 - 737 323 - 587 461 - 1093
SLAB OPTION FOR MINIMUM COST
Span
(m) Slab Type
Beam/Drop
thickness
(mm)
Slab
thickness
(mm)
Total Cost
(Dhs./m2)
4 Conventional 1-way slab 400 175 197
5 Conventional 2-way slab 450 175 206
6 Post-Tensioned Slab 180 180 216
7 Post-Tensioned slab and Drop
panel 315 180 217
8 Post-Tensioned slab and band
beam 400 210 247
9 Hollow core slab 850 335 258
10 Hollow core slab 850 390 271
11 Hollow core slab 850 390 271
12 Hollow core slab 850 470 310
13 Hollow core slab 850 470 308
14 Hollow core slab 850 570 329
15 Hollow core slab 900 570 330
16 T-Section slab 900 785 420
SLAB OPTION FOR MINIMUM SLAB THICKNESS
Span
(m) Slab Type
Beam/Drop
thickness (mm)
Slab thickness
(mm)
Total Cost
(Dhs./m2)
4 Conventional 2-way slab 400 175 206
5 Conventional 2-way slab 450 175 206
6 Post-Tensioned Slab 180 180 216
7 Post-Tensioned slab and Drop panel 315 180 217
8 Post-Tensioned slab and band beam 400 210 247
9 Post-Tensioned slab and Drop panel 420 240 266
10 Post-Tensioned slab and Drop panel 470 270 295
11 Post-Tensioned slab and Drop panel 525 300 333
12 Post-Tensioned slab and band beam 600 320 368
13 Post-Tensioned slab and band beam 650 340 398
14 Hollow core slab 850 570 329
15 Hollow core slab 900 570 330
16 T-Section slab 900 785 420
SLAB OPTION FOR MINIMUM STRUCTURAL DEPTH
Span
(m) Slab Type
Beam/Drop
thickness
(mm)
Slab
thickness
(mm)
Total Cost
(Dhs./m2)
4 Flat slab 180 180 228
5 Flat slab 220 220 268
6 Post-Tensioned Slab 180 180 216
7 Post-Tensioned Slab 210 210 242
8 Post-Tensioned Slab 240 240 270
9 Post-Tensioned Slab 270 270 299
10 Post-Tensioned Slab 300 300 327
11 Post-Tensioned Slab 330 330 355
12 Post-Tensioned Slab 360 360 410
13 Rib slab with filler block 550 550 440
14 Hollow core slab 850 570 329
15 Hollow core slab 900 570 330
16 T-Section slab 900 785 420
