Papers by Keyword: Wood

Abstract: Consideration was given to the issues relating to safety conditions and security arrangements during the thermal decomposition of wood at the time of the fire in the premises of domestic buildings. The data of experimental investigations obtained for the thermal decomposition of wood were given with the measurement data of the concentration of toxic gases (СО, СО₂), oxygen (О₂), and temperature depending on time and fire spreading conditions in the premises. The studies were carried out by comparing the changes in the temperature of the solid flammable materials with time and the emission intensity of toxic gas (СО, СО₂) under the limited oxygen access at the time of the fire. The research data confirm those obtained for the gaseous atmosphere composition in the premises during the thermal decomposition of the solid flammable materials.

Abstract: There are many valuable wooden buildings in the world, because timber has been used all over the world as a building material for a long time. However, there is an issue that timber deteriorates due to various factors. Therefore, in order to preserve these valuable wooden buildings, it is necessary to appropriately repair or reinforce treatment. One of the treatments is the resin filling method. In this method, filling the resin in order to restore the strength into an internal cavity caused by deterioration. It has become clear that it is possible to recover the strength using this method, however, we are still conducting construction based on the rule of thumb. Therefore, authors examined the resin characteristics in order to inject the resin in stable manner and ensure strength recovery. Authors focused on deteriorated timber due to termites, because Japan has a very high amount of such type of timber. Authors reports the following four aspects of the characteristics of resin filling into timber. 1. The Area velocity is determined by the injection pressure, width of the gap, and viscosity of the resin. 2. The resin spreads concentrically in the gap of wood, but there is no regularity in the random gap like deteriorated timber due to termites. 3. Authors proposed a new coefficient for the application, of a theoretical formula to deteriorated timber due to termites. 4. Authors proposed a flowchart of resin filling method to perform stable construction.

Abstract: Nowadays, smart technology plays an important role in engineering applications to improve the quality of life. Thus, the development of natural materials and the use of nanotechnology, will give wood new properties to maximize its benefit. It is clear that there is a great challenge to prove the strength and durability of wood acquiring new features to reach innovative use that can influence the current path in many engineering applications. Therefore, this paper summarizes a review of the possibility of using nano- and smart-technologies to make the most of the natural and acquired potential for adding new features and physical properties of wood to improve its efficiency in architectural and mechanical applications. Moreover, experiments have shown that the use of certain types of wood in many applications such as the manufacture of 3D vehicle simulation models to study dynamic behaviors as well as in the manufacture of mechanical measurement systems to improve accuracy. In conclusion, new directions under development in this field are proposed to provide solutions to important issues in the future of measurement and quality control systems that need scientific treatment.--

Abstract: The article presents the results of studies of the effect of lithium, sodium, potassium and ammonium nitrates on the physical and mechanical properties of aluminosilicate adhesives intended for gluing wood and structures based on them. Nitrates were introduced into the aluminosilicate adhesive of composition Na₂O·Al₂O₃·6SiO₂·20H₂O in amounts of 0.5, 1 and 1.5 wt. %. Changes in the shear strength along the fibers of substrates made of pine, beech, and oak wood were studied after 7 and 28 days of hardening of aluminosilicate adhesives in vivo. It is shown that for gluing pine wood it is most expedient to use adhesives containing lithium nitrate, potassium nitrate and ammonium nitrate is within 1.5 wt. %, the shearing strength along the fibers after 28 days of hardening is 1.7-1.8 times higher than the strength of the adhesive without additives. For gluing beech wood, it is most advisable to use adhesives containing potassium and ammonium nitrate in an amount of 1.5 wt. %, the shearing strength along the fibers after 28 days of hardening is 1.5 times lower than the strength of the adhesive without additives. For gluing oak wood, it is most advisable to use adhesives containing lithium nitrate, potassium nitrate and ammonium nitrate in amounts of 0.5 and 1.5 wt. %, the shear strength along the fibers increases by 1.3-1.5 times for 7 and 28 days of hardening compared to the strength of the adhesive without additives. According to the degree of influence on strength, modifying additives can be ranked in the series LiNO₃×3H₂O>KNO₃>NH₄NO₃>NaNO₃.

Abstract: Wood is a versatile material able to be used in a wide variety of situations and applications. Wood has also very good strength to weight ratio. Problem is degradation of wood due to bad external conditions. The protection of wood takes many forms including proper design detailing. The majority are directed towards the prevention of moisture access and weathering. However, there are also some design details that can also assist in reducing the risk of biological attack. Our work provides a background on a number of important subjects related to good performance of wooden structures. This paper deals with durability of wood, design for durability of wooden structures, surface modification of wood and also evaluation and monitoring of wooden structures.

Abstract: To enhance the quality of wood and extend its industrial applications, various methods of wood modification are being developed. It is well known that the thermal treatment of wood may considerably enhance its moisture resistance, reduce its hygroscopicity, and increase its rot proofing. However, reducing the absorptive capacity of wood adversely affects the process of obtaining wood-based composites. Pressure and pressing time increase, which finally increases the cost of the end product. Thus, this study represents the research in how ultraviolet exposure affects the physical properties of wood that has been pre-treated thermally, followed by obtaining a composite. An experimental wood-modifying facility has been developed. We have considered the process of the moisture absorption of the material that has been exposed to thermal modification and UV-radiation. From the experiments conducted, we have found that the UV exposure of wood samples causes an increase in the surface wettability of the thermally modified material. It is found that the most active process of surficial inactivation runs within 60-90 minutes of the UV-exposure of wood. Post-treatment does not result in any considerable changes in the surface wettability. This treatment promotes the increasing adhesion of water-borne binders to the material surface in developing high-strength composites based on modified wood.

Abstract: The effect of the composition on the weight loss of wood protected by a coating based on inorganic and organic substances in the process of thermal exposure, which is a feature of the study of the flame retardant effectiveness of the composition, is investigated. The solution of this problem is carried out by specially developed methods. The influence of fire protection under the influence of high-temperature heat flux on the change in the process of loss of mass of fire-protected wood is determined and the mechanism of kinetics of action of the composition is characterized, which is characterized by a decrease in the speed of flame propagation and mass loss. The results of thermogravimetric studies determined the weight loss of the coatings as a function of temperature, the results of which investigated the activation energy at the temperature decomposition of the coatings and found that for wood it was 36.56 kJ / mol, and in the case of fire protection it increased 2.3 times. which makes it possible to conclude that it is advisable to use lacquer varnish to improve the fire retardant efficiency of wood. Thus, for the specimen of fire-retardant lacquer wood, there is a gradual decrease in temperature, ie, the work of the coating is fixed, and, accordingly, the activation energy is increased during the decomposition of the wood. In order to establish the flame retardant efficiency in the application of high-temperature blowing lacquer, studies were conducted to determine the combustibility index of wood by mass loss, flame spread and temperature increase of flue gases and found that when processing wood goes to the group of combustible materials with a burning index.

Abstract: The aim of the work was to determination the combustibility group of color fire retardant paints for wood. As a result of the fire tests, it was found that the developed compositions of fire-retardant mineral paints on an alkaline aluminosilicate binder in the (Na, K)₂O-Al₂O₃-nSiO₂-mH₂O system are difficult to combustible and to flammable, and occupy a middle position between G1 and G2 in the combustibility group. As a result of the fire tests, the temperature of the flue gases did not exceed the critical value - above 260 [°C], the weight loss of the samples was in the range from 5.56 to 10.17 [%], and the burning rate did not exceed 0.0026 [kg/(m²s)]. Given the rather high margin of flue gas temperature, further fire tests are planned to be carried out according to EN 13823 in RICE Sweden.

Abstract: In this research, three ecological paints, based on linseed oil as the main component, are characterized and investigated to optimize their properties and utilization in protection of wood surfaces. The aim is to find the suitable parameters for the application and drying of the paints, which can guarantee a better protection of wood surfaces during outdoor utilization. Initially the three paints were characterized determining some of their chemophysical parameters, such as density, viscosity, dry content and glass transition temperature. Afterwards panels of pine wood (Pinus sylvestris L.) were coated and exposed to outdoor weathering (OW). During OW color changes and hydrophobicity are repeatedly measured and monitored to evaluate the efficiency of the paints. To minimize the discoloration of wood substrate, paint formulations include also different type of pigments in their composition.

Abstract: In this study, raw wood (RW) samples were impregnated with a mixture of furfural alcohol (FA), styrene (ST), and nanoclay of varying concentration of FA and ST. These impregnated wood and RWsamples were then subjected to FTIR, water uptake (WU), and thermal studies. The FT-IR results at 1600-1800 cm^-1 showed that the ST/FA/clay-WPNCs had different peak numbers with different positions compared with the RW. So, there was an interaction between RW, FA, ST and clay. The WU of ST/FA/clayimpregnated wood is lower than RW. In thermo gravematric result, below 100 °C the impregnated wood samples had less weight lost compared to RW.