PSI - Issue 11

Roberto Scotta et al. / Procedia Structural Integrity 11 (2018) 282–289 R. Scotta et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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6. Repetition of phases 1 to 4 in the next removed portions; 7. Laying of concrete to realize the new curb along the entire base of the wall. 7. Conclusions

The analysis of details of timber constructive elements in critical building zones, such as flat roofs, balconies, wet rooms and base of walls near concrete foundation, is of critical importance to ensure the durability of the structure. In this work, this last detail has been critically investigated and discussed. Traditional techniques, as RC curb or larch base beam, are suitable ways to ensure wood preservation, provided that a suitable waterproofing is realized, to permit a correct drying of timber when a moisture source increases over the limit condition of 20%. However, they present some disadvantages as excessive geometric inaccuracies of the RC curb and consequent incorrect alignment of the walls, or reduced load-bearing capacity of the larch base beam loaded in compression perpendicular to grain. A new aluminium bottom rail has been presented in this work. Experimental tests proved that the ultimate load bearing capacity of the aluminium profile is suitable for mid-rise timber buildings. This element was conceived for assuring the durability in new timber buildings, improving precision and speed of installation of walls, with respect to traditional techniques. The application of the aluminium system presented in this work demonstrates the excellent performance and potentiality for the construction of safe and durable wooden buildings. Finally, a proposal of application for restoring damages in existing timber buildings has also been hypothesized, discussing main phases for the removal of damaged parts, replacing them with the aluminium beam interposed between the healthy wall and a new RC curb. Acknowledgements The authors would like to thank Eng. Giulio Dalla Verde and Eng. Miriam Comunian for technical support in selecting and realizing figures and drawings. References Ceccotti, A., 2008. New technologies for construction of medium-rise buildings in seismic regions: the XLAM case. Struct. Eng. Int. 18(2), 156 165 Ceccotti, A., Sandhaas, C., Okabe, M., Yasumura, M., Minowa, C., Kawai, N., 2013. SOFIE project – 3D shaking table test on a seven-storey full-scale cross-laminated timber building. Earthquake Engng. Struct. Dyn. 42(13), 2003-2021 European Committee for Standardization, 2016. EN 755-2 - Aluminium and aluminium alloys. Extruded rod/bar, tube and profiles. Mechanical properties German Institute for Standardization, 2012. DIN 68800-2:2012-02 - Wood preservation - Part 2: Preventive constructional measures in buildings McClung, R., Ge, H., Straube, J., Wang, J., 2014. Hygrothermal performance of cross-laminated timber wall assemblies with built-in moisture: field measurements and simulations. Building and Environment 71, 95 – 110. DOI: 10.1016/j.buildenv.2013.09.008 Merotto, A., 2017. Danni e difetti delle costruzioni in legno. Diagnosi, punti critici, soluzioni. Maggioli Editore. (In Italian) Monfore, G.E., Ost, B., 1965. Corrosion of Aluminum Conduit in Concrete. Journal of Portland Cement Ass. 7, 10-22 ÖNORM B 2320:2017 08 01. Wooden residential houses - Technical requirements Ridout, B., 2000. Timber decay in buildings: the conservation approach to treatment. APT Bulletin: The Journal of Preservation Technology 32, 58-60 Ringhofer, A., Schickhofer, G., 2014. Multi-storey residential buildings in CLT – interdisciplinary principles of design and construction. In Proceedings of World Conference on Timber Engineering (WCTE), 10-14 August 2014, Quebec City, Canada Scotta, R., Marchi, L., Trutalli, D., Pozza, L., 2017. Engineered aluminium beams for anchoring timber buildings to foundation. Structural Engineering International 27,158-164. DOI: 10.2749/101686617X14881932435736 Silva, C., Branco, J., Lourenço, P., 2016. Strategies to avoid humidity causing damages in tall timber buildings. 41 IAHS world congress, 13-16 September 2016, Albufeira, Algarve, Portugal Tariku, F., Kwok, H., Simpson, Y., 2016. Experimental Investigation of Moisture Transfer between Concrete Foundation and Sill Plate. Journal of Architectural Engineering 22, B4016003 Teibinger, M., Matzinger, I., 2013. Construction with Cross-Laminated Timber in multi-storey buildings. Focus on building physics. Holzforschung Austria Toyoumi, A., Horisawa, S., Yoshimura, T., Doi, S., Imamura, Y., 2010. The effect of different foundation systems on the fungal flora in the crawl space of a new wooden Japanese house. Building and Environment 45, 1054-1060