PSI - Issue 44

Giacomo Iovane et al. / Procedia Structural Integrity 44 (2023) 1870–1876 Giacomo Iovane et al. / Structural Integrity Procedia 00 (2022) 000 – 000

1875

Re-construction/repair of timber members / joints Strenghtening of timber cross-section Reinforcement of timber floors with CLT panels

Fig. 3. Schematic representation of possible types of local interventions on RC and masonry buildings with timber-based elements.

3.4. Structural-plus-energy retrofitting solutions Timber-based materials are already by themselves interesting solutions for providing both structural and energetic retrofitting. In addition, the combination of timber-based elements with thermal insulating materials can make the systems even more sustainable and economically feasible. Further to most common natural materials, like for example the rock wool, it is worth noticing that Arundo Donax, it being the common cane, can be also used (Sessa et al., 2020, Amarone et al., 2021 ) . AD is easily available in many Mediterranean countries and commonly used as structural component in constructions of vernacular architecture. It is renewable, recyclable, the constructive process is non polluting and the Life cycle is sustainable. In the context of the seismic retrofitting, 2D// and 3D// endo- and exo-skeleton systems, as well as CLT panels used both as reinforcement or for the new realization of timber floors, if properly combined with thermally insulating materials, can regulate the internal thermal environment, increasing the thermal insulation of the building and reducing the energy consumption. In Figure 4 possible concepts to achieve simultaneous structural and energetic retrofitting in a building envelope with 2D// exo-skeleton systems with CLT or light frame structures, as examples, are presented for the case of RC framed and masonry structures. The solutions simply uses the CLT panels or timber light frames, together with additional insulation materials (Fufa et al, 2018; Ingrao et al, 2016; Dodoo et al, 2014), obtaining a prefabricated integrated system, realized directly in the production workshop and transported in the construction site for assembly only. This allows to achieve with only one intervention both the required structural safety and energy performance, while keeping low the overall cost thanks to the dramatic reduction of the labour cost for the prefabrication, featuring fast assembly.

Masonry buildings

RC buildings CLT - 2D// exo,RC,Wall

CLT - 2D// exo,M,Wall

Ligth frame - 2D// exo,M,Wall

Ligth frame - 2D// exo,RC,Wall

1: Masonry structure; 2: RC structure; 3: Vapor control / airtightness membrane; 4: CLT panels; 5: Light frame structure or braced frame; 6: Flexible wood fibre insulation between timber-joints; 7: Insulating wood fibre sheathing; 8: Drained and ventilated cavity; 9: Horizontal weatherboarding fixed to battens.

Fig. 4. Examples of CLT and light frame 2D// exo,RC,Wall structural-plus-energy retrofitting solution for RC and masonry buildings.

4. Conclusive remarks From the examination of timber-based systems for the retrofit of existing masonry and RC buildings, global and local interventions have been collected, pointing the attention to the integration of structural and energetic functions. Mainly, global types include timber exo- and endo-skeletons (CLT, LVL, light timber frame panel or timber X, V