PSI - Issue 59

Victor Datsiuk et al. / Procedia Structural Integrity 59 (2024) 583–587 Victor Datsiuk et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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One of the main tasks in construction is the erection of new buildings and structures, as well as extending the service life of existing ones (Bosak et al. (2021)). These constructions are composed of various materials, each with its specific physical and mechanical properties (Dvorkin et al. (2021); Gayda and Kiyko (2020); Green and Kretschmann (1992), Imbirovych et al (2023)). Many buildings incorporate products, load-bearing elements, and structures made of wood (Da Silva and Kyriakides (2007); Sobczak-Piastka et al. (2020), Gomon et al. (2023)). These can include windows, doors, flooring, beams, trusses, columns, arches, rafters, and others (Nsouami, et al. (2022), Gomon et al. (2022), De Mets and Tilmans (2020), Anshari et al. (2014)). They may be subjected to different thermal and moisture conditions (Homon et al. (2023), Janiak et al. (2023)).

Nomenclature Е

w ood elasticity modulus

ultimate compressive strength of wood along the fibers

f c,0,d

service life of wood

Т

Throughout the world, many buildings and structures were built decades, if not centuries, ago. Scientists and engineers are keenly interested in the condition of products, elements, and constructions after prolonged use. Some remain in satisfactory condition, while others require repair or reconstruction. Many of them are made of wood (Zhou et al. (2018), Homon et al. (2023), Sobczak-Piastka et al. (2023), Gomon et al. (2022)). Some scientists strive to determine the level of physical wear of such products, elements, and constructions over an extended period of use, while others investigate changes in mechanical properties using destructive and non-destructive methods. The aim of this work is to conduct experimental studies on wood samples after prolonged use and to identify changes in strength parameters. 2. Methods of experimental research The samples of pine wood with dimensions of 30x30x120mm were cut from solid elements and structures that had been in use under different thermal and moisture conditions. The service life was approximately 25, 50, and 75 years. There were 5 groups of samples for each moisture level (12% and 15%), cut from different locations. Moisture content was monitored using a needle moisture meter MD-814. Each group consisted of 5 samples. Prisms were cut from load-bearing elements of residential and public buildings, agricultural and industrial facilities: rafters, beams, trusses, arches, and columns (Fig.1a, Fig.1b).

b

a

Fig.1. Condition of load-bearing wooden elements after prolonged use: (a) 75 years; (b) 50 years.