fib congress 2006 Naples, Italy

1. Regression Based Criteria
Determining for Preservation
Strategies of Early RC Buildings
Maria BOSTENARU DAN
ROSE School / IUSS di Pavia

2. 2nd fib Congress, Napoli, 5-8 June 2006
Overview
 Introduction
 Historic concrete
 Problem statement
 Concrete today
 Innovative uses of concrete
 Lessons learned
 Decision considerations
 Conclusions

3. 2nd fib Congress, Napoli, 5-8 June 2006
Introduction
 Story of construction technique
(ex. Ostia: roman concrete > the vault)
 Existing buildings: stories on construction
concepts, materials, techniques
testimonials of innovation and spread
 Requirements and decay > intervention need
„The stones of Athens would not tell us the story of the urban life in the city,
wouldn‘t have all the written heritage remained.“
Lewis Mumford

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5. 2nd fib Congress, Napoli, 5-8 June 2006
Historic concrete

6. 2nd fib Congress, Napoli, 5-8 June 2006
Concrete today

7. 2nd fib Congress, Napoli, 5-8 June 2006
Concrete in time
 Gap between use in antique and today
 Natural stone for spatial structures in Gothic
 19th century: reinforcement
 RC in housing construction started to be
employed during the Avantgarde
 Some European capitals (RO, GR, PT):
high-rise in central areas – luxury flats
 Advanced construction technology was
employed but not all possibilities researched

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9. 2nd fib Congress, Napoli, 5-8 June 2006
Problem statement
 Condominium buildings
 Higher amount
 Less experiment on material use
 1930s
 Across Europe
 Romania, Italy, Greece, Portugal
 Compared to Germany and France

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11. 2nd fib Congress, Napoli, 5-8 June 2006
Innovative uses of concrete
 Architecture office Kramm εt Strigl, Darmstadt,
Germany
 Housing construction since 1975
 International recognition since 1983
 Potential for lessons learned:
housing construction with qualities above
common buildings – like Modern Movement

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Innovative use of concrete
 Texture-modenature
 Morphology and surface of glass and concrete:
Pallaswiesen street, Darmstadt, DE
 Role of concrete in the structure
 Various materials, employment in concordance with
the spatial feeling
Technology park and future centre, Herten, DE
 Technology
 Spatial cells
housing, Sauerland estate, Wiesbaden-Dotzheim, DE

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14. 2nd fib Congress, Napoli, 5-8 June 2006

15. 2nd fib Congress, Napoli, 5-8 June 2006
Innovative use of concrete
 Existing built substance
 Bürgerparkviertel, Darmstadt, DE
 Recycling procedure (TU Darmstadt)
 Technical and economic value

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17. 2nd fib Congress, Napoli, 5-8 June 2006
Lessons learned
 Recycling: testimony of the composition of the
material (demolition and rebuild)
 Spatial cells: frame serving as a shelf
 Ottokar Uhl, Hollabrunn, Austria
Individual measures for units in condominium

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Decision considerations
 Decision – element in a management process
 Decision – control options in operations
 Management dimensions
 Processural > decision
 Structural: organisational and operational structures
 Personal: system
 System: object | process
 Finding an optimal system for each group of actors
 Regression technique > instruments for systematic
decision

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2 Project objectives
 Development of a decentralised decision model
 Methodologic approach
modularisation of a collaborative decision model
 Non-measurable criteria, pairwise comparison
 Decision making on two levels: actors and actors‘ criteria
 Ways of solving contradictions between
objectives of single actors in the retrofit
implementation strategy
 Methodologic approach
development of a basis system to administrate
modules on different levels of detail included in the
urban strategical planning

20. 2nd fib Congress, Napoli, 5-8 June 2006
Actors and
groups of interests
 Organisational – architect
historical, building, element, material
 Social – inhabitant
execution, acceptability, use, residential val.
 Technical – engineer
vulnerability, structural performance,
retrofit, strategy
 Economic – investor
management, availability (of technology,
materials, funds), indicators

21. 2nd fib Congress, Napoli, 5-8 June 2006
[Nr.] Criterion [from] [to][unit] [weight]Observations (on the units)
1 Reversibility 0 100% 37,5reversibility of the measure
2 Guidelines 1 5points 37,5for the complinance with maintenance guidelines
5 Facade 1 4style points 9,0for the architectural value of the façade
6 Interiors 1 4spatiality points 9,0for the architectural value of the space
7 Structural system 1 4technology points 3,0for the architectural value of the structure
8 Demolition 0 100rebuild possibility 9,0of the building following the original plans
9 Size change 0 50cm 9,0size change of a building element
10 Looks change 1 5points 4,5look change of a building element
11 Material change 1 2000age (years) 9,0of the construction material
13 Compatibility 0 100% 4,5collaboration with the existing construction material
14 Conservation 0 100% 11,3maintenance of the existing building material
15 Sustainability 1 500years 2,3lifetime of the building
16
ARCHITECT
Maintenance 1 50years 4,5lifetime of the new construction material
17 Duration 1 100weeks 4,5of the measure
18 Noise 1 45dB 1,5noise during the measure
19 Move 1 100weeks 12,0duration of the relocation
20 Participation 0 15decision steps 12,0with possible participation of the inhabitants
21 Property form 1 5points 7,2lastingness of the inhabitance
22 Assurance 0 100% coverage 33,6earthquake damage through assurance
23 Own costs share 1 100% 4,8own costs/measure costs
24 Other advantages 1 5points 14,4for inhabitant advantages of the measure
25 During measures 0 200spaces 9,0usable during the measure
26 After measure 0 200spaces 15,0usable after the measure
27 After earthquake 0 200spaces 6,0usable after damaging in earthquake
29
USER
Value 1 20points 30,0for housing quality
33 Earthquake 1 12EMS intensity 27,5of the earthquake
34 Shape 8 10.10scores 5,0for seismic suitability of the conformation
35 Structure 0 8scores 15,0for seismic suitability of the structure
36 Material 1 6scores 2,5for seismic suitability of the construction material
37 Forces 0 1000kN base shear 35,0during the design earthquake
38 Remaining displacement 0 200mm 105,0at roof level after the earthquake
39 Maximal displacement 0 200mm 105,0at roof level during the earthquake
40 Strains -6 60‰ 105,0in building elements during earthquake
41 Element replacement 0 300number 25,0replaced elements
42 New elements 0 300number 7,5new elements
43 Nonstruct>struct 0 300number 10,0nonstructural elements which become structural
ENGINEER

22. 2nd fib Congress, Napoli, 5-8 June 2006
21 Property form 1 5points 7,2lastingness of the inhabitance
22 Assurance 0 100% coverage 33,6earthquake damage through assurance
23 Own costs share 1 100% 4,8own costs/measure costs
24 Other advantages 1 5points 14,4for inhabitant advantages of the measure
25 During measures 0 200spaces 9,0usable during the measure
26 After measure 0 200spaces 15,0usable after the measure
27 After earthquake 0 200spaces 6,0usable after damaging in earthquake
29
USER
Value 1 20points 30,0for housing quality
33 Earthquake 1 12EMS intensity 27,5of the earthquake
34 Shape 8 10.10scores 5,0for seismic suitability of the conformation
35 Structure 0 8scores 15,0for seismic suitability of the structure
36 Material 1 6scores 2,5for seismic suitability of the construction material
37 Forces 0 1000kN base shear 35,0during the design earthquake
38 Remaining displacement 0 200mm 105,0at roof level after the earthquake
39 Maximal displacement 0 200mm 105,0at roof level during the earthquake
40 Strains -6 60‰ 105,0in building elements during earthquake
41 Element replacement 0 300number 25,0replaced elements
42 New elements 0 300number 7,5new elements
43 Nonstruct>struct 0 300number 10,0nonstructural elements which become structural
44 Partial demolition 0 300number 7,5demolished elements
45 System completion 0 200needed anchors 5,0for a system completion measure
46 Strengthening/Stiffening 1 6Sa_new/Sa_old 15,0spectral acceleration new/old
47 Enhanced ductility 1 4Sd_new/Sd_old 20,0spectral displacement new/old
48
ENGINEER
Reduced demand 1 6damping actor 10,0of the soil movement
49 Aggregate 1 44nr. owners 8,0of the building
50 Building site 0 24hours available 12,0for the work
51 Phases 1 44simultaneous 12,0conducted
52 Repeatability 1 200nr. identical 8,0retrofit measures
53 Material versus 10 40price T€/app. 8,0construction material price for measure at one housing unit
54 Technology v. 0 10number 8,0available technologies
55 Funding money 0 10nr. programs 4,0which could grant funding money
56 Replace space 0 5eq. buildings 20,0available for the relocation
57 Reparation/Rebuild 0 2€/€ 5,0costs/costs
58 Retrofit/Rebuild 0 0.5€/€ 5,0costs/costs
59 Reparation-save/Retrofit -5 5€/€ 5,0costs/costs
60
INVESTOR
Total costs/Rebuild-30% -0.3 2.2€/€ 5,0costs/costs

23. 2nd fib Congress, Napoli, 5-8 June 2006
Building characteristics

24. 2nd fib Congress, Napoli, 5-8 June 2006
Regression:
goals of the architect
 Induction
 Data set:
preservation, configuration, survey characteristics
 Hypotheses:
minimal intervention in the original structure
 Deduction
 Hypothesis: retaining the character
 Hypotheses: element aspect
 Statements: size, looks, material change

25. 2nd fib Congress, Napoli, 5-8 June 2006
Regression:
goals of the investor
 Induction
 Data set: four economic efficiency alternatives
 Hypotheses:
taking into account non-measurable criteria
 Deduction
 Hypothesis: benefit-cost investigation
 Hypotheses: methods
(transformation curves, ranking algorithms etc)
 Statements: procedure to analyse the efficiency of
pre- versus post-damage reparation

26. 2nd fib Congress, Napoli, 5-8 June 2006
Retrofit alternative
First
earthquake
Second
earthquake
Reparation(€)
Retrofit(€)
Total(€)
Rebuild(€)
Reparation/
Rebuild
Retrofit/
Rebuild
Total/Rebuild
Total/Rebuild-
0,30
Reparation/
Retrofit
Retrofit/
Reparation
Differenceto
unretrofitted
(€)
Reparattionsa-
ving/Retrofit
EQ A - 506950 0 506950 1561534 0,32 0,00 0,32 0,02 - 0 -
EQ A EQ A 526850 0 526850 1561534 0,33 0,00 0,33 0,04 - 0 -
EQ B - 422000 0 422000 1561534 0,27 0,00 0,27 -0,03 - 0 -
B0
EQ B EQ B 423050 0 423050 1561534 0,27 0,00 0,27 -0,03 - 0 -
EQ A - 544400 74785 619185 1561534 0,34 0,04 0,39 0,10 7 0,13 0 0
EQ A EQ A 595400 74785 670185 1561534 0,38 0,04 0,42 0,13 8 0,12 0 0
EQ B - 422000 74785 496785 1561534 0,27 0,04 0,31 0,02 6 0,17 0 0
B1
EQ B EQ B 479850 74785 554635 1561534 0,30 0,04 0,35 0,06 6 0,15 0 0
EQ A - 553050 67987 621037 1561534 0,35 0,04 0,39 0,10 8 0,12 46100 1
EQ A EQ A 605250 67987 673237 1561534 0,38 0,04 0,43 0,13 9 0,11 78400 1
EQ B - 477100 67987 545087 1561534 0,30 0,04 0,34 0,05 7 0,14 55100 -6
B2
EQ B EQ B 478800 67987 546787 1561534 0,30 0,04 0,35 0,05 7 0,14 55750 1
EQ A - 580950 67987 648937 1561534 0,37 0,04 0,41 0,12 9 0,11 74000 1
EQ A EQ A 606650 67987 674637 1561534 0,38 0,04 0,43 0,13 9 0,11 79800 1
EQ B - 473900 67987 541887 1561534 0,30 0,04 0,34 0,05 7 0,14 51900 1
B3
EQ B EQ B 476700 67987 544687 1561534 0,30 0,04 0,34 0,05 7 0,14 53650 1
EQ A - 455100 135973 591073 1561534 0,29 0,08 0,37 0,08 3 0,29 -51850 -0
EQ A EQ A 596400 135973 732373 1561534 0,38 0,08 0,46 0,17 4 0,22 69550 1
EQ B - 345850 135973 481823 1561534 0,22 0,08 0,30 0,01 3 0,39 -76150 -1
B4
EQ B EQ B 408900 135973 544873 1561534 0,26 0,08 0,34 0,05 3 0,33 -14150 -0
EQ A - 422950 176765 599715 1561534 0,27 0,11 0,38 0,08 2 0,41 -506950 -3
EQ A EQ A 586250 176765 763015 1561534 0,37 0,11 0,48 0,19 3 0,30 59400 0
EQ B - 442600 176765 619365 1561534 0,28 0,11 0,39 0,10 3 0,39 -422000 -2
B5
EQ B EQ B 476700 176765 653465 1561534 0,30 0,11 0,41 0,12 3 0,37 53650 0

27. 2nd fib Congress, Napoli, 5-8 June 2006
Regression:
goals of the engineer
 Induction
 Data set: report on building types
 Hypotheses: problems and opportunities, retrofit
provisions, damage patterns
 Deduction
 Hypothesis: retrofit elements
 Hypotheses:
technical and management preservation strategy
 Statements: damage patterns

28. 2nd fib Congress, Napoli, 5-8 June 2006
Regression:
goals of the inhabitant
 Induction
 Data set: case studies of success stories in
participative planning and construction
 Hypotheses: participative planning approaches
 Deduction
 Hypothesis: innovation through pilot projects which
will become better routine
 Hypotheses: communication and education strategy
 Statements:
participation and communication instruments

29. 2nd fib Congress, Napoli, 5-8 June 2006
Computer support
 Costs-efficiency method: MS Excell
 Decision tree, Criterion weighting, Measurement space
 Moderation between interests of actors
 Difficulties
 Limited number of actors > 1st level: categories of actors
 Criteria strengthening / agravating reciprocically
 Finding units of measure
 Pair-wise comparison
 Spread sheet
 Multimedia
 Typological choice: Hypertext and internet

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31. 2nd fib Congress, Napoli, 5-8 June 2006
Conclusions
 Criteria for the selection of multi-storey RC structures
of housing buildings from the 1st half of the XXth
century to be preserved were formulated > ongoing
research towards the development of a decision
model, encompassing actors involved in the
implementation of a retrofit measure.
 Methodology:
modularisation of a collaborative decision model
taking into account non-measurable criteria
 Pair-wise comparison more useful than decision tree

32. Thank you!
Acknowledgements:
Marie Curie Intra-European Fellowship
MEIF-CT-2005-009765 contract
of the European Commission
Insights from Dr. Rui Pinho, Prof. Rüdiger Kramm