Azores seminar on stone housing - costs calculation

1. CALCULATION OF COSTSCALCULATION OF COSTS
FOR SEISMIC RETROFITFOR SEISMIC RETROFIT
OF STONE MASONRYOF STONE MASONRY
BUILDINGS IN GREECEBUILDINGS IN GREECE
Maria BOSTENARU DANMaria BOSTENARU DAN
Gregor BOURLOTOSGregor BOURLOTOS

2. OverviewOverview
►IntroductionIntroduction
►Description of the stone masonrDescription of the stone masonry built stocky built stock
in Greecein Greece
►Description of the retrofit measuresDescription of the retrofit measures
►Determination of costsDetermination of costs
►Discussion and conclusionsDiscussion and conclusions

3. IntroductionIntroduction
►The majority of population lives in existingThe majority of population lives in existing
buildings and will further live in thesebuildings and will further live in these
►BBuildinguilding retrofitretrofit is important for theiris important for their
assurance in earthquake prone regionsassurance in earthquake prone regions
►Ressources are limited, therefore economicRessources are limited, therefore economic
efficiencefficiency is importanty is important
►Stone masonry spread in GreeceStone masonry spread in Greece
►Building element method from Germany, aBuilding element method from Germany, a
method which doesn’t require databasesmethod which doesn’t require databases

4. Description of the stone masonryDescription of the stone masonry
built stock in Greecebuilt stock in Greece
►Tassios and Syrmakezis (2004) WHETassios and Syrmakezis (2004) WHE
►Historic centres of Greek citiesHistoric centres of Greek cities
►Seismic performance is poorSeismic performance is poor
►Load bearing structure: unreinforced stoneLoad bearing structure: unreinforced stone
masonry walls out of rubble stone with limemasonry walls out of rubble stone with lime
mortarmortar
►floor and roof structures: timber structuresfloor and roof structures: timber structures

5. Description of the stone masonryDescription of the stone masonry
built stock in Greecebuilt stock in Greece
►Damaged in the Athens 1999 earthquake:Damaged in the Athens 1999 earthquake:
 partial collapse of walls,partial collapse of walls,
 collapse of corners,collapse of corners,
 separation of the two walls converging at aseparation of the two walls converging at a
cornercorner
 extensive crackingextensive cracking
►Vertical and horizontal reinforced concreteVertical and horizontal reinforced concrete
confining elements improve the behaviourconfining elements improve the behaviour

6. Description of the stone masonryDescription of the stone masonry
built stock in Greece (source: WHE)built stock in Greece (source: WHE)

7. Description of the retrofit measuresDescription of the retrofit measures
►Retrofit measures in case of pre-damagedRetrofit measures in case of pre-damaged
buildingsbuildings
►Strengthening of a non-damaged buildingStrengthening of a non-damaged building

8. Retrofit measures in case of pre-Retrofit measures in case of pre-
damaged buildingsdamaged buildings
►Extensive crackingExtensive cracking
►Buckling of masonry wallsBuckling of masonry walls

9. Retrofit measures in case ofRetrofit measures in case of
extensive crackingextensive cracking
►the plaster is largely removed,the plaster is largely removed,
►the rift is enlarged to several centimetresthe rift is enlarged to several centimetres
with hammer and chipper,with hammer and chipper,
►the rift is cleaned with air under pressure,the rift is cleaned with air under pressure,
►the rubble rests are removed,the rubble rests are removed,
►the rift is filled with cement or reparationthe rift is filled with cement or reparation
mortar,mortar,
►the plaster is re-established.the plaster is re-established.

10. Retrofit measures in case ofRetrofit measures in case of
extensive crackingextensive cracking

11. Retrofit measures in case of bucklingRetrofit measures in case of buckling
of masonry wallsof masonry walls
►the loads are catched with a support andthe loads are catched with a support and
lead into the load bearing foundation,lead into the load bearing foundation,
►the old wall is demolished,the old wall is demolished,
►a new wall is built,a new wall is built,
►the wall is loaded again (the support isthe wall is loaded again (the support is
unmounted).unmounted).

12. Retrofit measures in case of bucklingRetrofit measures in case of buckling
of masonry wallsof masonry walls

13. Retrofit measures as preventiveRetrofit measures as preventive
measuresmeasures
►Retrofit measures in case of lack ofRetrofit measures in case of lack of
confinement of the cornerconfinement of the corner
►Retrofit measures in case of nonRetrofit measures in case of non
corresponding confinement of the openingscorresponding confinement of the openings
►Shotcreting of the wallShotcreting of the wall
►Creation of a ring beamCreation of a ring beam

14. Retrofit measures in case of lack ofRetrofit measures in case of lack of
confinement of the cornerconfinement of the corner
► the roof and floor loads are caught with a scaffoldthe roof and floor loads are caught with a scaffold
construction,construction,
► it is bolted in two directions on the inner side of theit is bolted in two directions on the inner side of the
wall,wall,
► the masonry is demolished and disposed,the masonry is demolished and disposed,
► the corner column is reinforced,the corner column is reinforced,
► forming – concreting – stripping of the cornerforming – concreting – stripping of the corner
column,column,
► creating reinforced masonry in the zone of thecreating reinforced masonry in the zone of the
corner column.corner column.

15. Retrofit measures in case of lack ofRetrofit measures in case of lack of
confinement of the cornerconfinement of the corner
Unloading of the wall in order to add confinement

16. Retrofit measures in case of lack ofRetrofit measures in case of lack of
confinement of the cornerconfinement of the corner

17. Retrofit measures in case of nonRetrofit measures in case of non
corresponding confinement of thecorresponding confinement of the
openingsopenings
► the old door and door frame are demolished andthe old door and door frame are demolished and
disposed,disposed,
► the eventually existing lintel is also demolishedthe eventually existing lintel is also demolished
and disposed,and disposed,
► the masonry adjacent to the door opening isthe masonry adjacent to the door opening is
demolished and disposed,demolished and disposed,
► the reinforcement of the reinforced concrete framethe reinforcement of the reinforced concrete frame
is anchored in the floor slab,is anchored in the floor slab,
► the other reinforcement works are done,the other reinforcement works are done,
► it is formed – concreted – stripped,it is formed – concreted – stripped,
► the new door is introduced.the new door is introduced.

18. Retrofit measures in case of nonRetrofit measures in case of non
corresponding confinement of thecorresponding confinement of the
openingsopenings

19. Retrofit measures in case of nonRetrofit measures in case of non
corresponding confinement of thecorresponding confinement of the
openingsopenings

20. Shotcreting of the wallShotcreting of the wall
► removal of the plaster,removal of the plaster,
► removal of the mortar up to 1 cm deep with a steelremoval of the mortar up to 1 cm deep with a steel
brush,brush,
► cleaning the wall with water,cleaning the wall with water,
► shotcreting in a thickness of 4-8 cm. Alternativelyshotcreting in a thickness of 4-8 cm. Alternatively
a cast in place concrete jacketing of 10 cma cast in place concrete jacketing of 10 cm
thickness can be done. The reinforcement has athickness can be done. The reinforcement has a
diameter of 8/25. The new wall has to be anchoreddiameter of 8/25. The new wall has to be anchored
in the existing masonry wall.in the existing masonry wall.

21. Shotcreting of the wallShotcreting of the wall

22. Determination of costsDetermination of costs
►Overview of German costs estimationOverview of German costs estimation
methodsmethods
►Approach to costs calculation of retrofitApproach to costs calculation of retrofit
methodsmethods
►Examples of costs calculationExamples of costs calculation

23. Overview of German costsOverview of German costs
calculation methodscalculation methods
 Costs estimation:Costs estimation:
►building divided in spaces with different functionsbuilding divided in spaces with different functions
►database necessarydatabase necessary
►suitable in incipient stages of planningsuitable in incipient stages of planning
 Costs calculationCosts calculation
►Building elements divided according to theirBuilding elements divided according to their
execution typeexecution type
►Later stages of planning, more preciseLater stages of planning, more precise
►Different levels of deepnessDifferent levels of deepness
►Neddermann: old building elementsNeddermann: old building elements

24. Approach to costs calculation ofApproach to costs calculation of
retrofit measuresretrofit measures
►Retrofit elementsRetrofit elements
 recognition characteristics,recognition characteristics,
 construction works with duration/neededconstruction works with duration/needed
resources,resources,
 implied works for retrofit/reparation,implied works for retrofit/reparation,
 earthquake resilient features, seismicearthquake resilient features, seismic
deficiencies and earthquake damage patternsdeficiencies and earthquake damage patterns

25. Examples of costs calculationExamples of costs calculation
►Reparation of cracking in the wallsReparation of cracking in the walls
►Reparation of buckled wallsReparation of buckled walls
►Retrofit of cornersRetrofit of corners
►Retrofit of door framesRetrofit of door frames

26. Reparation of cracking in the walls:Reparation of cracking in the walls:
small rifts in non-bearing wallssmall rifts in non-bearing walls
No. Operation Unit Working
time/un
it
Price/unit
(€)
Number of
units
Price /
time
(€)
Whole
price
(€)
1 Removal of the plaster
on big surface
m 0.3 h 1 36 10.8
2 Enlarging the rift with
hammer and chisel
m 0.2 h 1 36 7.2
3 Cleaning the rift m 0.1 h 1 36 3.6
4 Filling the rift with
mortar
m 0.1 h 1 36 3.6
Reparation mortar m 5 1 5
5 Transport of the
removed plaster to
container
m 0.07 h 1 36 2.52
6 Disposal of the removed
plaster
m³ 13+18.40 0 0.05
7 New plaster m 0.14 h 36 5.04
Plaster mortar m 2.5 1 2.5
Price m rift 40.31

27. Reparation of cracking in the walls:Reparation of cracking in the walls:
rifts in load bearing wallsrifts in load bearing walls
No. Operation Unit Work
time/unit
Price/unit
(€)
Number
units
Price/ time
(€)
Whole
price (€)
1 Large removal of the plaster m 0.3 1 36 10.8
2 Preparation of the base m 0.2 1 36 7.2
3 Drilling m 0.2 1 36 7.2
4 Cleaning of the drill holes m 0.2 1 36 7.2
5 Battering the packer m 0.2 1 36 7.2
6 Isolating m 0.2 1 36 7.2
7 Verifying the patency m 0.2 1 36 7.2
8 Turning in the nipples m 0.2 1 36 7.2
9 Injection m 0.2 1 36 7.2
Injection means m 5 1 5
10 Postinjection m 0.2 1 36 7.2
11 Removing the isolation m 0.2 1 36 7.2
12 Chipping out the packer m 0.2 1 36 7.2
13 Closing the drill hole m 0.2 1 36 7.2
14 Disposal of the removed plaster m³ 13+18.4 0 0.05
15 New plaster m 0.14 1 36 7.2
Plaster mortar m 2.5 1 2.5
Price m rift 111.95

28. Reparation of buckled wallsReparation of buckled walls
No. Operation Unit Work
time/
unit
Price/unit
(€)
Number
of
units
Price
/time
(€)
Whole
price
(€)
1 Bolts to support the floor piece 2 h 1 36 72
2 Demolition of masonry m³ 5,6 h 1 36 201.6
3 Disposal of demolished
masonry
m³ 13+6 1 19
4 Stonewalling of the
demolished walls
m³ 5.48 h 1 36 197.3
Stones piece 0.25 275 68.75
Mortar litre 3.125/27 233 26.96
Price m³
wall
585.61

29. Retrofit of cornersRetrofit of corners
No. Operation Unit Work
time/u
nit
Price/unit
(€)
Number of
units
Price/time
(€)
Whole price
1 Bolten in two directions piece 2 h 1 36 72
2 Demolition of masonry m³ 5.6 h 4.38 36 883.01
3 Disposal of the demolished masonry m³ 13+(46/2.5) 4.38 137.53
4 Reinforcement of the corner column piece 0.5 h 1 36 18
Steel (100kg/m³ concrete) t 500 0.05 25
5 Forming the corner column piece 20 min 1 36 13.5
Formwork m² - 8.5 10 - 85/4
Formwork support m - 0.55 25 - 13.75/4
6 Concreting the corner column piece 1 h 1 36 36
Concrete m³ 140 0.48 67.2
7 Striking the corner column piece 20 min 1 36 13.5
8 Stonewalling the demolished walls
(20% more height for the
anchoring of the reinforcement)
m² 2 h 9.6 36 691.2
Masonry stones stone 250/1000
pieces
960 240
Mortar litre 3.125/27 l 816 94.44
Price corner 2448.69

30. Confinement of door framesConfinement of door frames
No. Operation Unit Work time/
unit
Price/unit (€) Number of
units
Price/ time (€) Whole price
1 Demolition of the door and the door frame
including the transport to the building
site rubble container
door 0.5 h 1 36 18
2 Disposal of the doorframe and the door t 225 0.04 9
container 46 0.25 11.5
3 Demolition of the masonry including the
transport to the building site rubble
container
door 0.5 h 1 36 18
4 Disposal of the demolished masonry m³ 13+46/2.5 0.3 9.42
5 Cleaning of the demolished masonry rests
with steel brush in order to remove
rubble rests
door 0.5 h 1 36 18
6 Reinforcement steel of the door frame out of
reinforced concrete anchored in the
floor
hole 0.5 h/ 8 holes 8 36 18
7 Reinforcement door 45 min. 1 36 27
Steel t 500 0.02 7.5
8 Forming (the door frame has the function of
framework for concreting)
door 20 min 1 36 13.5
9 Concreting door 1 h 1 36 36
Concrete m³ 140 0.3 42
10 Stripping the forms door 20 min 1 36 13.5
11 Acquisition of the door and assembly piece 368 1 368
Price door
frame
609.42

31. Discussion and conclusionsDiscussion and conclusions
►The employment of the method doesn’tThe employment of the method doesn’t
improve the whole buildingimprove the whole building
►Employed in the past years more and moreEmployed in the past years more and more
in Greecein Greece
►In Greece stone buildings experience atIn Greece stone buildings experience at
least an earthquake during their lifetimeleast an earthquake during their lifetime
►Targeted measures are task of theTargeted measures are task of the
engineersengineers

32. Discussion and conclusionsDiscussion and conclusions
N
o
.
Measure Costs
1 Small rifts in non-bearing masonry walls 40.31 € / m rift
2 Rifts in load bearing masonry walls 111.95 €/ m rift
3 Rehabilitation of buckled masonry walls 585.61 € / m³
4 Confinement of masonry corners 2448.69 €
/corner
5 Confinement of door frames 609.42 € /door
frame

33. Discussion and conclusionsDiscussion and conclusions
►Stone masonry houses spread throughoutStone masonry houses spread throughout
the world:the world:
 Algeria, India, Iran, Italy, Nepal, Pakistan,Algeria, India, Iran, Italy, Nepal, Pakistan,
Portugal, Slovenia, and Switzerland (WHE)Portugal, Slovenia, and Switzerland (WHE)
 historic, heritage buildingshistoric, heritage buildings
 no databases of previous performed worksno databases of previous performed works
►The method is useful, all needed are pricesThe method is useful, all needed are prices
of materials and of the hour of workof materials and of the hour of work
►No affirmation about certaintyNo affirmation about certainty

34. Discussion and conclusionsDiscussion and conclusions
►Research into the structural behaviour ofResearch into the structural behaviour of
seismic retrofit measures is much moreseismic retrofit measures is much more
spread than in the side of application andspread than in the side of application and
economic efficiency.economic efficiency.
►The work presented here builds a begin.The work presented here builds a begin.

35. Thank you!Thank you!