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Structural and health assessment of historic timber roofs from the Convent of Christ in Tomar

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Abstract

Before coming up with any important decision of intervention in the restoration process of existing buildings, the assessment of the conservation state is required as regards heritage timber structures and especially for those that suffered a lack of maintenance in their service life. In that context, three timber roof structures from the Convent of Christ in Tomar, Portugal, were selected and investigated. To this end, a research methodology was introduced and applied to these case studies into four main steps: (1) visual inspection; (2) non-destructive wood diagnosis; (3) structural safety evaluation; (4) prevention and intervention measures. For the visual inspection, every element and joint constituting the roof structures received scrutiny through assessing the wood species, the different construction stages and, last but not least, their respective geometry. As regards the encountered pathologies, structural disorders (e.g. accidental failure, serviceability defects…) and wood deteriorations due to biological agents (e.g. wood-destroying fungi or insects), which ineluctably leads to a likely decrease of the mechanical performances of the roof structure, were reported. To estimate the residual element cross section and elastic modulus, wood diagnosis was carried out using three relevant non-destructive tests: (1) ultrasonic pulse velocity; (2) drilling resistance; (3) impact penetration. From the collected data, the three timber roof structures were modelled on a commercial software to check their safety and integrity. Based on those outcomes, some prevention and intervention measures haves been lastly proposed case by case.

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Source: A Terceira Dimensão, http://portugalfotografiaaerea.blogspot.com

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Adapted from interventions on the decayed timber beam end [36]

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References

  1. Verbist M, Nunes L, Jones D, Branco JM (2018) Chapter 11: service life design of timber structures. In: Ghiassi B, Lourenço PB (eds) Long-term performance and durability of masonry structures—degradation mechanisms, health monitoring and service life design—part III: long-term performance and service life design, 1st edn., pp 311–336. https://doi.org/10.1016/B978-0-08-102110-1.00011-X

    Chapter  Google Scholar 

  2. Freas A (1982) Evaluation, maintenance and upgrading of wood structures—a guide and commentary. American Society of Civil Engineers (ASCE), New York

    Google Scholar 

  3. Teles CDM, Do Valle A (2001) Wood structures: acting before deterioration. In: Lourenço PB, Roca P (eds) Historical constructions. University of Minho, Guimarães, pp 857–866

    Google Scholar 

  4. Sousa HS, Branco JM, Lourenço PB (2014) Da inspeção de segurança na reabilitação de estruturas de madeira. In: Sousa HS, Branco JM, Lourenço PB (eds) Intervir em construções existentes de madeira—Livro de Atas. Escola de Engenharia, Guimarães, pp 57–70

    Google Scholar 

  5. Cruz H, Yeomans D, Tsakanika E, Macchioni N, Jorissen A, Touza M, Mannucci N, Lourenço PB (2015) Guidelines for on-site assessment of historic timber structures. Int J Archit Herit 9(3):277–289. https://doi.org/10.1080/15583058.2013.774070

    Article  Google Scholar 

  6. Riggio M, Tannert T (2016) Structural assessment: diagnosis, before intervention! In J. Eberhardsteiner WW, Fadai A, Pöll M (eds) World conference on timber engineering—WCTE 2016. Vienna, Austria. August 22–25, 2016. ISBN: 978-3-903039-00-1

  7. ICOMOS Charter (1999) Principles for the preservation of historic timber structures. In: International council on monuments and sites—ICOMOS. 12th General Assembly. Mexico, October 1999

  8. ICOMOS Charter (2003) Principles for the analysis, conservation and structural restoration of architectural heritage. In: International council on monuments and sites—ICOMOS, 14th general assembly. Victoria Falls, Zimbabwe

  9. Yeomans D (2003) The repair of historic timber structures. Thomas Telford Ltd, London

    Book  Google Scholar 

  10. Bertolini C, Touliatos P, Miltiadou N, Delinikolas N, Crivellaro A, Marzi T, Tsakanika E, Pignatelli O, Biglione G (2007) The timber roof of Hagia Paraskevi Basilica in Halkida, Greece: multi-disciplinary methodological approaches for the understanding of the structural behaviour. Analysis and diagnosis. In: ICOMOS IWC—XVI international symposium. From material to structure—mechanical behaviour and failures of the timber structures. Florence, Venice and Vicenza, Italy. November 11–16, 2007

  11. Branco JM, Piazza M, Cruz PJS (2010) Structural analysis of two King-post timber trusses: non-destructive evaluation and load-carrying tests. Constr Build Mater 24:371–383

    Article  Google Scholar 

  12. Croatto G, Turrini U (2014) Restoration of historical timber structures—criteria, innovative solutions and case studies. In: Sousa HS, Branco JM, Lourenço PB (eds) Intervir em construções existentes de madeira—livro de Atas. Escola de Engenharia, Guimarães, pp 119–136

    Google Scholar 

  13. Tampone G, Ruggieri N (2016) State-of-the-art technology on conservation of ancient roofs with timber structure. J Cult Herit 22:1019–1027

    Article  Google Scholar 

  14. Morandotti M, Zamperini E, Lucenti S, Adrea D’M (2016) Expeditious survey of historic timber roofs. An applied research for Palazzo San Felice in Pavia, Italy. In: Eberhardsteiner J, Winter W, Fadai A, Pöll M (eds) Proceedings of the world conference on timber engineering—WCTE 2016. Vienna, Austria. August 22–25, 2016

  15. Candelas-Gutiérrez A, Borrallo-Jimenez M (2018) Methodology of restoration of historical timber roof frames Application to traditional Spanish structural carpentry. Int J Archit Herit. https://doi.org/10.1080/15583058.2018.1506833

    Article  Google Scholar 

  16. Macchioni N, Mannucci M (2018) The assessment of Italian trusses: survey methodology and typical pathologies. Int J Archit Herit 12(4):533–544. https://doi.org/10.1080/15583058.2018.1442516 (Special Issue on “Existing Timber Structures)

    Article  Google Scholar 

  17. Barbosa A (2009) Habitar o Património: o Caso do Convento de Cristo. Máthesis 18(177–193):2009

    Google Scholar 

  18. da Silva JRM (2014) Convent of Christ in Tomar: insight into 20th century interventions. Master thesis in Architecture. Lusíada University, May 7, 2014, Lisbon, Portugal

  19. Mendonça I, Marques L, Branco R, Matias C (2006) Convento de Cristo/Mosteiro de Cristo (IPA.00004718/PT031418120002). SIPA—Sistema de Informação para o Património Arquitectónico, Lisbon Archived on September 15, 2015

    Google Scholar 

  20. Cuartero J, Cabaleiro M, Sousa HS, Branco JM (2019) Tridimensional parametric model for prediction of structural safety of existing timber roofs using laser scanner and drilling resistance tests. Eng Struct 185:58–67. https://doi.org/10.1016/j.engstruct.2019.01.096

    Article  Google Scholar 

  21. Jasienko J, Nowak T, Hamrol K (2013) Selected methods of diagnosis of historic timber structures. Principles and possibilities of assessment. Adv Mater Res 778:225–232. https://doi.org/10.4028/www.scientific.net/AMR.778.225

    Article  Google Scholar 

  22. EN 350 (2016) Durability of wood and wood-based products. Testing and classification of the durability to biological agents of wood and wood-based materials. CEN, European Standardisation Institute. Brussels, Belgium

  23. EN 1912 (2012) Structural timber—strength classes—assignment of visual grades and species. CEN, European Standardisation Institute. Brussels, Belgium

  24. EN 338 (2016) Structural timber—strength classes. CEN, European Standardisation Institute. Brussels, Belgium

  25. UNI 11035-2 (2003) Structural timber—visual strength grading rules and characteristics values for Italian structural timber population. Ente Nazionale Italiano di Unificazione, Milano

    Google Scholar 

  26. Sandoz JL, Benoit Y, Demay L (2000) Wood testing using Acousto-ultrasonic. In: Proceedings of the world conference on timber engineering—WCTE 2000. Whistler Resort, British Columbia, Canada. July 31–August 3, 2000

  27. Drdácký MF, Kloiber M (2006) Non-destructive survey of historic timber. In: Binda L, Drdácký M, Kasal B (eds) In-situ evaluation and non-destructive testing of historic wood and masonry structures. RILEM workshop, Czech Republic, Prague, pp 8–23. ISBN: 978-80-86246-36-9

    Google Scholar 

  28. Feio AO, Lourenço PB, Machado JS (2007) Non-destructive evaluation of the mechanical behavior of chestnut wood in tension and compression parallel to grain. Int J Archit Herit 1(3):272–292. https://doi.org/10.1080/15583050701300475

    Article  Google Scholar 

  29. Drdácký MF, Kloiber M, Kotlínová M (2006) Low invasive diagnostics of historic timber. In: Binda L, Drdácký M, Kasal B (eds) In-situ evaluation and non-destructive testing of historic wood and masonry structures. RILEM workshop, Czech Republic, Prague, pp 24–41. ISBN: 978-80-86246-36-9

    Google Scholar 

  30. Tannert T, Anthony RW, Kasal B, Kloiber M, Piazza M, Riggio M, Rinn F, Widmann R, Yamaguchi N (2014) In situ assessment of structural timber using semi-destructive techniques. Mater Struct 47(5):767–785. https://doi.org/10.1617/s11527-013-0094-5

    Article  Google Scholar 

  31. Nowak T, Jasieńko J, Hamrol-Bielecka K (2016) In situ assessment of structural timber using the resistance drilling method—evaluation of usefulness. Constr Build Mater 102(Part 1):403–415. https://doi.org/10.1016/j.conbuildmat.2015.11.004

    Article  Google Scholar 

  32. Dlubal software GmbH®(2019) Structural engineering software for analysis and design. RFEM, Version 5.19.01. Germany

  33. EN 1995-1-1 (2004) Eurocode 5—design of timber structures—part 1.1: general—common rules and rules for buildings. CEN, European Standardisation Institute. Brussels, Belgium

  34. UNI 11119 (2004) Cultural heritage—wooden artefacts—load-bearing structures—on site inspections for the diagnosis of timber members. Ente Nazionale Italiano di Unificazione, Milano

    Google Scholar 

  35. Lourenço PB, Sousa HS, Brites RD, Neves LC (2013) In situ measured cross section geometry of old timber structures and its influence on structural safety. Mater Struct 46(7):1193–1208. https://doi.org/10.1617/s11527-012-9964-5

    Article  Google Scholar 

  36. Arriaga F, Peraza F, Esteban M, Bobadilla I, Garcia F (2002) Intervención en estructuras de madera. AITIM ltd, Madrid

    Google Scholar 

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Acknowledgements

This work was financed by FEDER funds through the Competitively Factors Operational Programme—COMPETE and by national funds through FCT—Foundation for Science and Technology within the scope of the research project INVISIBLE WOODS PTDC/EPH-PAT/2401/2014, and the PhD Scholarships SFRH/BD/128580/2017. Besides, we would also like to acknowledge Prof. Cristina Nabais, from the University of Coimbra, for her collaboration dealing with the dendrochronological part and, last but not least, the DGPC for opening the doors to the wonderful Convent of Christ in Tomar and for the permission to investigate the timber roof structures in the dormitory Room 68 and Knights’ Hall.

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Verbist, M., Matos, F.T. & Branco, J.M. Structural and health assessment of historic timber roofs from the Convent of Christ in Tomar. J Civil Struct Health Monit 9, 491–511 (2019). https://doi.org/10.1007/s13349-019-00347-6

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