Strength of aged wood in old constructions

Fedyukov, Vladimir; Chernov, V. Yu.; Chernovà, Maria

doi:10.5937/jaes18-23002

Cited by 5 publications

(3 citation statements)

References 6 publications

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“…Wood aged in old structures differs in its physical and mechanical properties from fresh wood [14]. Artificially accelerated aging tests can simulate the aging of wood and save time.…”

Section: Introductionmentioning

confidence: 99%

Influence of Wetting-Drying Cycles on Wood Behaviour of Coastal Pedestrian Walkways

Ferreira¹,

Delgado²,

Parauta³

et al. 2023

Recent Prog Mater

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In the context of inspection and maintenance actions for beach walkways in the North of Portugal, some samples of wood used in their construction were collected – the <em>Pinus</em> <em>sylvestris</em> wood, widely applied in the country. The sustainability of the beach walkways over natural coastal areas is very dependent on their material durability. One of the main problems of the timber used to build those structures is its behavior under wet-drying cycles. For that reason, this work aimed to simulate the effects of weathering on the long-term bending behavior of pinewood. Weathering slab samples with two decades of service life and new, unused slabs were subjected to wetting–drying cycles and tested between each wetting or drying phase. As the bending test characterizes one of the most representative efforts in pedestrian boardwalk slabs, the bending module of rupture was used as an indicator to characterize the resistance of timber. Thus, in this study, the samples' density, dimensional stability, and mechanical strength were determined at the end of each batch of cycle repetitions. The tests were carried out before and after a set of wetting-drying cycles caused by immersion in water and placement into an oven at 80°C to simulate environmental exposure. Thus, it was intended to simulate the use in service through the realization of successive wetting-drying cycles in a laboratory environment and to evaluate its influence on the density, dimensional stability, and mechanical strength of the pine wood tested. The extreme conditions used in the laboratory pretend to accelerate the degradation of samples and simulate, in a relatively short period, what would need years to occur in service. The results showed that the wood that had never been in service is more susceptible to bending resistance variations with cycles than the one already in service. Thus, after a few wet-drying cycles, the wood without any service life tends to approximate, in terms of bending behavior, to the one with two decades of service. This indicates that the method used could satisfy the need to obtain predictions for long-time behavior in a relatively short period.

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“…Wood aged in old structures differs in its physical and mechanical properties from fresh wood [14]. Artificially accelerated aging tests can simulate the aging of wood and save time.…”

Section: Introductionmentioning

confidence: 99%

Influence of Wetting-Drying Cycles on Wood Behaviour of Coastal Pedestrian Walkways

Ferreira¹,

Delgado²,

Parauta³

et al. 2023

Recent Prog Mater

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show abstract

“…Material testing, calibration, and analysis are the essential processes in the material and structural characterizations of materials that are possibly subjected to various loads in technical applications [1][2][3][4][5][6][7]. The main material testing variable is hardness, which represents the resistance properties due to deformation and destruction.…”

Section: Introductionmentioning

confidence: 99%

Design development and technical analysis of an auto checking hardness machine: A study case of the hardness tester HR-522 series

et al. 2021

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A hardness-checking machine is a crucial tool in engineering study, especially in the mechanical and manufacturing process. It usually used to measure, calibrate, and standardize the quality of the product. It is based on the field problem in Akebono Brake Astra Indonesia for using more manual tools to achieve product demands. It is considering those issues, the development of a modified hardness checking tool from manual operation to automatic operation. Using automatic operation is useful in time and savings for other manual tools. The automatic tool applies the 3-axes system mechanism using Festo linear actuator with the servo motor. The testing capacity of automatic devices is equal to more manual devices. The frame of the auto-checking hardness machine is assessed by applying load variations. From the other similar work of auto checking hardness machine, this paper provides the comparison of various aluminum frame types based on different tensile strength and cross-sectional area values. The other analysis is calculating the base plate for hardness testing. There are 9 points of testing to calculate the use of linear guides for the base plate. The results are the excellent value of tensile strength has good results of displacement and maximum stress.

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“…Summarizing the relevant research in recent years, it is found that the basic mechanical properties of wood, such as MOE, bending strength, and compressive strength, are affected by factors, such as environmental temperature and humidity, which eventually show changes with use time. For example, Fedyukov et al (2020) have found that the physical properties (compressive strength and flexural strength) of wood structures that have been used for more than 70 years are different from those of new wood, and these changes will have an impact on the structural force performance during the whole life cycle of timber structure. Huang et al (2008) took the old wood replaced during the repair of the Hall of Valor in the Imperial Palace as the test material to study the changes in the physical and mechanical properties of wood structures after more than 100 years of use and found that their physical and mechanical properties changed due to long-term use.…”

Section: Introductionmentioning

confidence: 99%

Effects of accelerated weathering test on the properties of larch wood

Cheng

Zhao

et al. 2021

BioRes

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To investigate the changes of larch wood properties under the influence of long-standing exposure to the environment, the QUV accelerated weathering tester (fluorescent UV and condensation testers) was used to accelerate the weathering of wood within a given preset time, and the changes were studied by analogue simulation. The wood color changed noticeably under different weathering time, and it gradually darkened from light yellow to deep reddish brown. Scanning electron microscopic (SEM) analysis revealed that as the weathering time increased, the cell wall was broken, the pits were cracked, and the tracheids were damaged. The results of the energy spectrum analysis (O/C (oxygen/carbon)) showed an increasing trend in the ratio, indicating that the wood underwent an oxidation reaction induced by light. From the values of the two testing indexes and their change patterns with weathering time, the same trend was observed, with the values of modulus of elasticity (MOE) in static bending being greater than that in dynamic bending Ed (the dynamic modulus of elasticity). However, the variability of MOE was greater than that of Ed. A comparative analysis of the two detection indicators was performed. The relationship between the proposed combined correction Ed and weathering time was: y = 0.0000001017 t2 – 0.0006 t + 9.77.

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Strength of aged wood in old constructions

Cited by 5 publications

References 6 publications

Influence of Wetting-Drying Cycles on Wood Behaviour of Coastal Pedestrian Walkways

Influence of Wetting-Drying Cycles on Wood Behaviour of Coastal Pedestrian Walkways

Design development and technical analysis of an auto checking hardness machine: A study case of the hardness tester HR-522 series

Effects of accelerated weathering test on the properties of larch wood

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