Wood Modification and Wood Preservation
َAmir Mohamad Nahofteh Estarabadi; Davood Rasouli; Taghi Tabarsa; Abolghasem Khazaeian
Abstract
Background and Objectives: Wood, as an organic material, is susceptible to deterioration by destructive factors such as fungi and insects. One approach to protect against these factors is the treatment of wood with preservatives. The use of waterborne preservatives is common due to the numerous advantages. ...
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Background and Objectives: Wood, as an organic material, is susceptible to deterioration by destructive factors such as fungi and insects. One approach to protect against these factors is the treatment of wood with preservatives. The use of waterborne preservatives is common due to the numerous advantages. However, when preservative-treated wood is exposed to outdoor environments, it becomes susceptible to weathering and leaching. The use of coatings can be an effective method in this regard. This research investigates the effectiveness of two transparent coatings, acrylic and alkyd, in enhancing the weathering resistance of wood specimens treated with waterborne preservatives. .Methodology: defect-free poplar wood specimens with dimensions of 12×10×2 cm3 (L, T, R) were prepared and then they were treated with preservatives ACC, CCB, and ACQ-C using the full-cell/pressure impregnation method. Subsequently, acrylic and alkyd transparent coatings were applied to the surface of the specimens. After applying the coatings, the specimens were exposed to natural weathering for one year.Results: The results indicated that the type of coating significantly influenced the color and adhesion resistance of specimens. Furthermore, the research findings demonstrated that all specimens experienced color changes and a decrease in coating adhesion resistance due to weathering. Among the coatings, the intensity of color changes and deterioration in specimens with acrylic coatings was higher compared to those with alkyd coatings. Conclusion: In general, it can be concluded that alkyd coatings exhibited better preservative performance against weathering for preservative-treated wood.Background and Objectives: Wood, as an organic material, is susceptible to deterioration by destructive factors such as fungi and insects. One approach to protect against these factors is the treatment of wood with preservatives. The use of waterborne preservatives is common due to the numerous advantages. However, when preservative-treated wood is exposed to outdoor environments, it becomes susceptible to weathering and leaching. The use of coatings can be an effective method in this regard. This research investigates the effectiveness of two transparent coatings, acrylic and alkyd, in enhancing the weathering resistance of wood specimens treated with waterborne preservatives. .Methodology: defect-free poplar wood specimens with dimensions of 12×10×2 cm3 (L, T, R) were prepared and then they were treated with preservatives ACC, CCB, and ACQ-C using the full-cell/pressure impregnation method. Subsequently, acrylic and alkyd transparent coatings were applied to the surface of the specimens. After applying the coatings, the specimens were exposed to natural weathering for one year. .Results: The results indicated that the type of coating significantly influenced the color and adhesion resistance of specimens. Furthermore, the research findings demonstrated that all specimens experienced color changes and a decrease in coating adhesion resistance due to weathering. Among the coatings, the intensity of color changes and deterioration in specimens with acrylic coatings was higher compared to those with alkyd coatings.Conclusion: In general, it can be concluded that alkyd coatings exhibited better preservative performance against weathering for preservative-treated wood. .Conclusion: In general, it can be concluded that alkyd coatings exhibited better preservative performance against weathering for preservative-treated wood. .
Hojat Hematabadi; Mehrab Madhoushi; Abolghasem Khazaeian; Ghanbar Ebrahimi
Abstract
This study investigated the bending and shear strength of hybrid cross-laminated timber (CLT) manufactured from beech (Fagus orientalis) and poplar (Populus deltoides) wood using experimental and finite element methods. The CLT panels were manufactured at various span to depth ratios 6, 10, 15, 20 and ...
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This study investigated the bending and shear strength of hybrid cross-laminated timber (CLT) manufactured from beech (Fagus orientalis) and poplar (Populus deltoides) wood using experimental and finite element methods. The CLT panels were manufactured at various span to depth ratios 6, 10, 15, 20 and 25 with width of 30 cm and thickness of 2 cm in both major and minor directions. Then, the bending and shear strength of CLTs were measured using three-point bending test according to ASTM test methods. The results indicated that with the increase of span to depth ratio of the beam from 6 to 25, the averages modulus of elasticity (MOE) and modulus of rupture (MOR) values were increased in both major and minor directions. On the contrary, the averages shear modulus ( ) values of specimens in both directions were decreased. Moreover, the results of finite elements showed that the amounts of stress distributions and their locations were different in major and minor directions of the beam. In the major direction, the surface layers were primarily contributed load-carrying capacity of CLT panels, while in the minor direction the middle layer played the most significant role for load-carrying capacity. In this research, it was resulted that specimens with span to depth ratio greater than 15 based on ASTM D198 can be used for calculating MOE and MOR of CLT panels. Furthermore, due to existence of lower difference than 10% between experimental and numerical results, modules of elasticity of CLTs were predictable according to finite element method
Composite wood products
Mostafa Yahyavi; Abolghasem Khazaeyan; Alireza Shakeri
Abstract
Abstract The aim of this research is the possibility of using black liqour and nano Graphene oxide (GO) for making three-layer particle board. In this study, the amount of black liqour was as 0, 10, 20 and 30 percent and Graphene oxide was 0, 0.25 and 0.5 percent (based on oven dried weight of UF). Wood ...
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Abstract The aim of this research is the possibility of using black liqour and nano Graphene oxide (GO) for making three-layer particle board. In this study, the amount of black liqour was as 0, 10, 20 and 30 percent and Graphene oxide was 0, 0.25 and 0.5 percent (based on oven dried weight of UF). Wood particles was pressed with using a laboratory hydraulic press. Mechanical and physical properties (modulus of rupture, modulus of elasticity, internal bonding, water absorption and thickness swelling after 2 and 24h soaking in water) of the produced boards were measured according to EN standards. The effect of each of the variables was studied on the properties and analyzed at 95 percent with using SPSS software and variance analysis factorial design. The results showed that increasing black liqour resulted in decreasing the modulus of rupture, modulus of elasticity and internal bonding. The results also indicated that water absorption and thickness swelling after 2 and 24h soaking in water increased with increased black liqour and Graphene oxide percent. The results show that increasing of nano ghraphen resulted in increasing modulus of rupture, modulus of elasticity and internal bonding.
