Pilot study on inventory and condition of stock of materials at risk at UNESCO cultural heritage sites Report 73 Prepared by the sub centre of cultural heritage and mapping Stefan Doytchinov, Pasquale Spezzano, Augusto Screpanti, Giovanni Leggeri 30 th ICP Materials Meeting, Swerea KIMAB, Kista, Stockholm, April, 2014

Pilot study on inventory and condition of stock of materials at risk at UNESCO cultural heritage sites Part I - Methodology. Report 68 (November 2011). Part II - Determination of stock of materials at risk for individual monuments. Report 70 (September 2012). Part III - Economic evaluation. Report 73 (November 2013).

Tolerable corrosion rate based on background corrosion rates and the target for 2050 y. (n=2.5) and the target for 2020 y.(n=2.0) Material Background corrosion depth (BCD) Factor for acceptable corrosion Tolerable corrosion rate per year Limestone3.2 µm 2020 target (2.5 times BCD) 8.0 µm year -1 Limestone3.2 µm 2050 target (2.0 times BCD) 6.4 µm year -1 The average tolerable rate for corrosion and maintenance intervals for limestone/marble are(2): TABLE 2Type of surfaceCorr. depth before Tolerable time between action (µm)maintenance (years)Ornament – aged 10012Ornament – corroded 506The average tolerable rate for corrosion and maintenance intervals for limestone/marble are(2): TABLE 2Type of surfaceCorr. depth before Tolerable time between action (µm)maintenance (years)Ornament – aged 10012Ornament – corroded 506

The average tolerable rate for corrosion and maintenance intervals for limestone/marble are

Assume The cost of the intervent for limestone (marble) is: 440 € m -2 The tolerable corrosion for monuments “aged” is : 100 µm The tolerable corrosion for monuments “corroded ” is : 50 µm

Effect of corrosion rate on corrosion cost for sensitive ornament in a corroded state.

Effect of corrosion rate on corrosion cost for sensitive ornament naturally aged

Greece, Athens – The Parthenon Total surface : 3798 m 2 Corrosion depth after one year of expossure : 5,7 µm Calculated life time of the monument between two intervents of reparation/maintenance is: Life time aged = 17,6 years Life time corroded = 8,8 years Estimate of the costs of the intervents due to the corrosion: K aged = 41 k€ year -1 K corroded = 82 k€ year -1

France, Paris – Le facades in the centre of the city Total surface : m 2 (100% limestone). Corrosion depth after one year of expossure : 5,8 µm Calculated life time of the monument between two intervents of reparation/maintenance is: Life time aged = 17,3 years Life time corroded = 8,7 years Estimate of the costs of the intervents due of the corrosion : K aged = 823 k€ year -1 K corroded = 1646 k€ year -1

Czech Republic, Prague – The Klementinum (The National Library) Total surface : 8644 m % (windows&doors) = m 2 Corrosion depth after one year of expossure : 6,2 µm Calculated life time of the monument between two intervents of reparation/maintenance is: Life time aged = 16,2 years Life time corroded = 8,1 years Estimate of the costs of the intervents due to the corrosion : K aged = 57 k€ year -1 K corroded = 114 k€ year -1

Germany, Berlin - Neues Museum Total surface : 5400 m % (windows&doors) = 2700 m 2 Corrosion depth after one year of expossure: 8,2 µm Calculated life time of the monument between two intervents of reparation/maintenance is: Life time aged = 12,2 years Life time corroded = 6,1 years Estimate of the costs of the intervents due to the corrosion : K aged = 59 k€ year -1 K corroded = 118 k€ year -1

UK, Bath - Royal Crescent Total surface : 8293 m % (windows&doors) = 4147 m 2 Corrosion depth after one year of expossure : 4,8 µm Calculated life time of the monument between two intervents of reparation/maintenance is: Life time aged = 20,6 years Life time corroded = 10,3 years Estimate of the costs of the intervents due to the corrosion : K aged = 30 k€ year -1 K corroded = 60 k€ year -1

Strategies of the reduction of the costs of conservation reducing the air pollutants SO 2 PM 10 HNO 3 pH Greece, Athens – The Partenon ٧ France, Parice – Facades of centre of the city ٧٧ Czec Republic, Praghe - Klementinum (National Library) ٧ Germany, Berlin - Neues Museum ٧ UK, city of Bath - Royal Crescent ٧

Conclusions Calculation of the Direct Cost for Maintence and Repair Evaluation of conservation and renovation cost for limestone Evaluation of tolerable time between maintenance (years) Model for Calculating Costs due to Air Pollution Estimation of Air pollutant Dose-Exposure Cost for selected Stock at Risk of Cultural Heritage

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