Increasing the use of wood biomass is relevant at all stages of wood harvesting and processing. This is because up to 50% of the tree biomass is unused waste that is incinerated or buried. In this regard, sawmill waste is processed into technological chips for fiberboard production. This article presents the results of a study on fiberboard production with the addition of coniferous wood greenery. The expediency of the heat treatment and extraction of coniferous wood greenery was assessed before grinding to various degrees. Based on the analysis of the results of a two-factor experiment, regression dependencies and response surfaces were obtained, describing the effect of the needle content of various degrees of grinding on the total mass of the physical and mechanical properties of composite materials (in the form of a fiberboard obtained by a wet method). The optimal values of the input parameters for fiberboard production with excellent physical and mechanical properties were determined. The research results will contribute to the sustainable development of the country's timber industry by increasing the efficiency of wood biomass utilization and the production of special-purpose fiberboards, thereby enhancing their competitiveness compared to modern composite materials.

The rise in industrial activity and human population has increased fossil fuel consumption. Consequently, Indonesia has promoted a decarbonization program to achieve carbon neutrality or net-zero emissions, including developing renewable energy from biomass. However, comprehensive information on the potential biomass sources for power plants remains limited. To address this, this study investigated the potential of four local shrub species (bungur, Lagerstroemia speciosa; locong, Ganophyllum falcatum; latte, Myrsine avenis; and terasa, Mischocarpus sundaicus) and bamboo (paring: Gigantochloa atter) as alternative energy sources for co-firing in power plants. These materials were processed into biopellets and evaluated according to the Indonesian National Standard 8951-2020. The results indicated that shrub and bamboo biopellets met the Indonesian National Standard requirements for density, moisture, ash, carbon, and mineral contents. Compared to bamboo, shrub biopellets exhibited superior properties, including higher density, lower moisture and ash contents, higher fixed carbon, and higher calorific value, whereas the volatile and mineral contents were similar for both. Among the shrubs, M. avenis showed the most promise for further development because it had the lowest moisture (3.2%), ash (1.5%), K₂O (0.18%), and Na₂O (0.0001%) contents and a relatively high calorific value (3,836 kcal/kg) compared to the other materials tested.

Many houses and wooden constructions in East Kalimantan Province use keruing and meranti wood. Local carpenters widely use ordinary and concrete nails to join the wood. One of the factors affecting the corrosion rate of nails in wood is the extractive compound. Unfortunately, the amounts and types of keruing and meranti wood extractives and their effects on the corrosion rates of ordinary and concrete nails have not been studied. This study aimed to determine the amount and types of keruing and meranti wood extractives and their effects on the corrosion rates of ordinary and concrete nails. Wood extractive content was determined according to TAPPI 204 cm-97. A gas chromatograph-mass spectrometer test determined the chemical compound content of wood extractives. The electrochemical test measured the corrosion rate according to modified ASTM 199-09. The study showed that keruing wood contained 3.83% extractives and was dominated by cyclic carbon compounds. Meranti wood contained 1.97% extractives, and contained sulfurous acid, cyclohexylmethyl pentadecyl ester, which is acidic and therefore accelerates the rate of nail corrosion faster than keruing wood extractives. The lowest corrosion rate was found on cocrete nails in keruing wood extractive media, 0.65104 ㎛/year. The highest corrosion rate was found in ordinary nail in meranti wood extractives, 3.7434 ㎛/year. The nail corrosion rate in the keruing wood extractive media was lower than in the meranti wood extractive media.

Wood has different cell composition and characteristics depending on the wood species, and even though they are the same species, their characteristics can differ depending on the growing area. Therefore, in order to use wood effectively, it is very important to accurately know the characteristics of wood according to the wood species and the appropriate use for it. Tulip trees have been widely planted throughout South Korea since the early 2000s because they grow quickly, have excellent environmental adaptability, and have excellent carbon absorption capabilities. In this study, the anatomical properties (length and width of the trachea, cell wall thickness), physical properties (specific gravity and shrinkage), mechanical properties (bending strength, compressive strength, tensile strength, shear strength, hardness), and chemical composition (ash, extract, lignin, total sugar content) of Tulip tree which was grown in Gangjin-gun, Jeollanam-do, South Korea were evaluated. The evaluation results show that the Tulip tree, a fast-growing species, has low specific gravity, relatively low strength, and a chemical composition similar to general hardwoods.

This study analyzed the distribution and species of termites living in Korea. Eighty-five localities were selected for the study, and subterranean termites were collected from three colonies per locality. The morphological and genetic species analysis of the collected termites revealed three species: Reticulitermes speratus kyushuensis, Reticulitermes kanmonensis, and Reticulitermes speratus speratus. The drywood termite found in Jinhae-gu, Changwon, Gyeongnam, was analyzed as Incisitermes minor. By looking at the temperature of the termites' habitat, the air temperature in Korea, and the ground temperature, all of the termites analyzed were found to be suitable for living in Korea. If the temperature rises further due to global warming, the number of active days of termites and the introduction of new termite species will increase. Therefore, damage to wooden cultural heritage, wooden facilities, and wooden structures caused by the existing subterranean termites and alien termite species that attack dry wood is a concern, and measures should be taken accordingly.

Laminated wood is produced as a single large element by combining pieces of elements. Wooden building materials are used in several old buildings that survive to the present day. To strengthen wooden structures, they must be preserved in accordance with their originality without damaging their historical texture. In this study, an innovative strengthening method was developed by placing carbon-fiber-reinforced polymer (CFRP) fabrics between wooden planks before lamination. With this new strengthening method, CFRP fabrics were placed between the layers, preserving aesthetics and preventing crack formation. Notable improvements were observed in the strength properties of the reinforced wood material and the CFRP-reinforced layers exhibited ductile behavior by preventing damage. The laminated wood arch-reinforced sample with CFRP strips showed a 70% load increase and a 276% deformation increase compared with the reference sample. Because of these superior features, arch elements made of laminated wood offer a safe, durable, and natural solution for the passage of extremely wide openings. Additionally, wooden elements have anisotropic and heterogeneous structures owing to their defective areas. Eliminating the factors that cause wood to display anisotropic properties ensures the homogeneity of the resulting material through the lamination process. The aim is to reduce the cross sections used in wooden construction elements reinforced with these fabrics in the production area and to shorten the construction period by minimizing manufacturing errors.

This study established a standardized test method for the in-plane shear modulus of cross-laminated timber (CLT) KS F 2082. Among the test methods used to evaluate the in-plane shear modulus of CLT, the picture frame method was considered appropriate for achieving a pure shear state. However, the test procedures for the picture frame method have varied among studies owing to the lack of a standardized test method. Therefore, the deformation measurement area and loading protocol are discussed herein. The measurement area was determined based on the shear behavior of the test specimens using digital image correlation. The tensile and compressive deformations were similar when the side measurement area length was less than 70% of the side length of the test specimen. In addition, a three-stage loading protocol, including a two-step preloading, was proposed to settle the specimen during loading. Testing of a plywood panel showed that the difference between tensile and compressive deformations decreased as the stages progressed. Considering the larger difference in the first phase compared to the subsequent phases, it was concluded that at least one preloading step was required to achieve a pure shear state. A CLT specimen was tested following these procedures and exhibited linear load-deformation curves with a small difference (2.0%) in the tensile and compressive directions. Therefore, the test procedure proposed in KS F 2082 appears to be suitable for achieving a pure shear state and is an effective testing method for CLT.