CEMENT 091030stirnimann.ppt

Construction techniques –
present situation and trends
Course for Cement Applications 2008
Daniel Stirnimann
HGRS/CS

2
04.09.2022
Holcim Group Support Course for Cement Applications
Objectives
 Understand the importance of cost, time and quality
issues for the construction process
 Identify the key success factors for contractors as an
end user of cement and concrete
 Understand the influence parameters to optimize
construction processes by cement and concrete
performance

3
04.09.2022
Content
 Market typology
 Project key success factors
 Conventional construction methods
 Advanced construction methods

4
04.09.2022
Source: OECD; HVC Fact Bases; HGRS-CSS
100
1'000
10'000
100'000
0% 20% 40% 60% 80% 100% Current Holcim
bulk ratio [%]
Degree of cement market industrialization (efficiency potential)
Level of wealth
(potential for
growth)
GDP / capita
2004 [US$]
CH
FBNL
Australia
CAN
GER
Italy
Spain Singapore
Venezuela
Bulgaria
Slovakia
Croatia
Hungary
Thailand
Chile
Romania
Bangladesh
Morocco
Malaysia
Vietnam
Indonesia
Mexico
Panama
Libanon
Brazil
Argentina
Colombia
Ecuador
Costa Rica
Philippines
Sri Lanka
Nicaragua
Austria
Czech
Serbia
New Zeal.
South Africa
USA
India
La Reunion
Emerging markets
Developing markets
Transition markets
Mature markets
Market typology: Four market types identified
Focus on working processes and future trends in mature markets

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04.09.2022
Content
 Market typology

6
04.09.2022
E.g. building construction: Project cost break down
Estate Con-
struction
Fees Total
20
65
15
12
53
100
Con-
creting
Cement
0.5
Investment 100 Mio
Area 36’000 m2
Concrete 13’000 m3
Cement 4’000 t
Com. area 29’000 m2
Rent 300 CHF/m2 y
Impact of load bearing system cost on total building cost is limited
[Mio. CHF]
Cost of load
bearing
system only
~10 –15%
of total
investment

7
04.09.2022
1. year 2. year 3. year
Planning
Excavation
Construction
Facade
Installation
Interior system
Finish
10 months
Time for load bearing system
 On the critical path
 Rarely parallel processes possible
Significant potential to minimize total construction
time by accelerating building of load bearing system
E.g. building construction: Project schedule

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04.09.2022
E.g. building construction:
Value accelerated construction process for owner
Reduce cost:
2 months shorter
building credit
Increase revenue:
2 months earlier /
increase rent
0.6
1.4
2.0
[Mio CHF]
Total value
for owner
2% of total investment
16% of load bearing
system cost
400% of cement cost
Factors for reducing cycle time
 Formwork, reinforcement process
 Strength development concrete
 Demolding formwork
 Acceleration construction processes
may lead to significant customer value
 Time as key factor for cost savings
8 months

9
04.09.2022
E.g. building construction:
Project organization and specification
Specifications in contracts:
Performance oriented to take advantage of contractor’s know-how,
free choice of working process
Opportunity for RMX and contractors for differentiation
Cement producers needs know-how to support
contractors in different applications and processes
Developer
General
Contractor
Investor
Specifiers
Architect
Civil Eng.
…
Excavation
Contractor
Site manager
…

10
04.09.2022
Content
 Market typology
 Foundation applications
 Vertical elements: Walls and columns
 Horizontal elements: Slabs and beams
 Summary

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04.09.2022
Foundation application types
Mass foundation
 Mass concrete, low heat required
 High density of reinforcement
 Big pours, up to 800 m3 per day by
different RMC suppliers
 Sometimes durability required
(sulfates – aggressive soils)
 Complicated and high density of
reinforcement  concrete workability
 Homogeneity (concrete -
reinforcement) to ensure force
transition
 Surface quality less important
 Final strength important
Ground beam
High quality requirements, but limited time saving potential

12
04.09.2022
Content
 Market typology
 Summary

13
04.09.2022
Walls and columns:
Work flow concreting for load bearing elements
Reinforcement
Placing
Setting
Curing
Final
strength
Early
strength
Formwork
Critical job cycle:
Reuse of formwork for the
following element
Concrete strength:
~4 MPa required for demolding
the next day (~16h)
Cycle time for vertical elements can be significantly influenced
by concrete performance, therefore early strength is decisive

14
04.09.2022
Walls and columns:
Formwork for conventional and fast track projects
Conventional Fast track
 Manually lifted panels, slow
 Old, often reused wooden
panels
 Leaking, impacts surface
quality
Economical unit cost
Wooden or aluminum panels
lifted by crane, fast
 Limited life cycle per panel
Good surface quality to save
work for rework
 High unit costs

15
04.09.2022
Content
 Market typology
 Summary

16
04.09.2022
Slab and beams:
Work flow concreting for load bearing elements
Reinforcement
Placing
Setting
Curing
Demolding:
3d up to 7d
Final
strength
Early / mid
strength
Formwork
Job cycle:
Access on horizontal element for
ongoing working process
Concrete setting time and strength development has significant
influence on job cycle time and working processes
4 - 6h
Construction material:
Optimization of demolding material

17
04.09.2022
Content
 Market typology
 Summary

18
04.09.2022
Conventional construction methods
Foundation Slab / beam
Wall / column
 Strength
development
 Early strength
 Final strength
Key workflow
requirement
 Final strength
 Durability
 No cracking
 Final strength  Final strength
 Limited deflection
 No cracking
Owners long term benefit oppositional to short
cycle time interest of concrete end users
Working
practice
 Quality aspects
Benefit
owner
 Dem. @ 16h  Dem. @ 3 - 7d

19
04.09.2022
Content
 Market typology
 Vertical elements: Jump and slip forms
 Pre-cast products for vertical and horizontal elements
 SCC applications
 Summary

20
04.09.2022
Jump form application process
 Working process
 Plumb inside formwork
 Place the reinforcements
 Close outside formwork
 Concreting
a) Lifting by crane
 Lift external climbing unit
Only 5 to 10 min crane time per lift
 Lift the inside shaft formwork
b) Self climbing formwork
 Hydraulic compactors lift the formwork
 Suitable for lift shafts
 No changes of the shape nor wall inclinations
 Size limitations

21
04.09.2022
Jump form application benefits
 Acceleration of process
 Large shiftable units
 Quick suspension system
 Cost reduction
 Large surface area on the
platforms
 Work to be carried out safely
and easily behind and in front of
the formwork
 Reuse of formwork
 No vertical scaffolding
Job cycle time strongly limited
by early strength performance

22
04.09.2022
Slip form application process
 Hydraulic jacks elevate the formwork
of the complete structure in a
continuous vertical sliding motion as
concrete placing progresses
 Suitable for monolithic structures as
silos, tanks, chimneys, towers, water
towers, lift-shaft cores, tanks
 No changes of the shape
 Platform size limitations

23
04.09.2022
Slip form application benefits
 Acceleration of process
 Accelerated, permanent
construction time, no “job
cycles”
 Cost reduction
 Minimal form and space
requirements
 Low personnel expenses
 Quality
 Monolithically cast
structure free from ties and
cold joints
Time to completion strongly
limited by early strength
performance

24
04.09.2022
Content
 Market typology
 Summary

25
04.09.2022
Advantages of pre-cast elements
Smooth and even surface
Early strength concrete on job site not critical
Easy to handle by crane (weight)
~50% faster than conventional wall
construction
 Higher unit costs than conventional walls
‘Sandwich’ walls
Pre-cast slabs
Lower cycle time and high surface quality are main advantages
Smooth and even surface
Concrete strength on job site not critical
Easy to handle by crane (weight)
Faster than conventional slab construction
No formworks required
 Higher unit costs than conventional slabs

26
04.09.2022
ICF applications
 Insulated Concrete Forms (ICF) are
molds that have built-in insulation
 The hollow blocks are stacked and
filled with reinforcing bar and concrete
 The wall is structurally sound,
insulated, has a vapor barrier and is
ready to accept final exterior and
interior finishes
 Suitable for exterior wall systems
(residential and non-residential)
 Saves wall formwork and is easy
to handle (home builders)
 Need for high slump concrete
>160mm

27
04.09.2022
Content
 Market typology
 Summary

28
04.09.2022
CPM: Advantages of SCC applications
 Labor intensive placing
 To reduce failure rate, often significant
cost for rework
 High density of reinforcement and inlays
Fast and simple placement of concrete
Excellent surface quality
 Increased material cost
SCC
Standard concrete
Excellent off-form finish is main advantage of SCC for CPM

29
04.09.2022
Jobsite applications
Advantages of SCC applications
SCC placing
 Placing wall concrete by only one
worker (reduction labor force)
 High surface quality and less
concrete finish and rework
 Possibility to pour up to
15 meters in one go

30
04.09.2022
Content
 Market typology
 Summary

31
04.09.2022
Benefits of advanced construction methods
SCC Pre-cast
Jump / slip form
 CPM: Early strength
 Concrete: High
slump and flowability
 Concrete slump and
flowability
 High early strength
Require-
ment
Trend to shorter process cycles leads usually to higher installation
and material cost and allows in return to reduce labor cost
Benefits  Faster construction
process
 Surface quality
 Labor cost
saving
 Surface quality
 Faster construction
progress

CEMENT 091030stirnimann.ppt

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