• Journal of the Korean Wood Science and Technology
• /
• v.45 no.5
• /
• pp.640-649
• /
• 2017

A comparative research on the traditional standard wood walls and other light-frame wood walls is necessary to expand the base of wooden buildings and improve consumer satisfaction. Therefore, in this research we looked for new possibilities through comparison of performance between standard wood wall and newly presented staggered stud wood wall. First, the strength characteristics of staggered stud wood walls were evaluated and the those of standard wood walls were compared. The ultimate load of the standard wall was larger than that of the staggered stud wood wall, because the cross section of the wood making up the standard wood wall was larger than that of the staggered stud wood wall. However, the statistical analysis between the two groups didn't showed a significance of 95% confidence level. This means that, staggered stud wood walls have shown the possibility of replacing the standard wood wall. Because the cross-section of the stud in the staggered stud wood walls is smaller than that of the standard wall, the material can be saved. Therefore, staggerd wood stud wall is judged to be more economical than the standard wall. In addition, since the area of the insulation also increases, improvement of the heat bridge is also expected.

• Journal of the Korean Wood Science and Technology
• /
• v.51 no.1
• /
• pp.58-66
• /
• 2023

In light-frame timber construction, the shear wall is one of the most important components that provide resistance to lateral loads such as earthquakes or winds. According to KDS (Korea Design Standard) 42 50 10, shear walls are to be constructed using wood-based structural sheathing, with studs connected by 8d nails spaced 150 mm along the edge and 300 mm in the field. Even though small-scale residential timber building can be designed to exhibit seismic resistance using light-frame timber shear walls in accordance with KDS 42 50 10, only the abovementioned standard type of timber shear wall is available. Therefore, more types of timber shear walls composed of various materials should be tested to measure their seismic resistance, and the results should be incorporated into the future revision of KDS 42 50 10. In this study, the seismic resistance of shear walls composed of structural timber studs and wood-based structural sheathing with reinforced nailing is tested to evaluate the effects of the reinforcement. For the nailing reinforcement, shear wall specimens are constructed by applying nail spacings of 75-150 mm and 50-100 mm. For the shear wall specimens with one sheathing and reinforced nailing, the shear strengths are 1.7-2.0 times higher than that of the standard shear wall (nail spacing of 150-300 mm). The shear strength of the shear walls with sheathing on both sides is 2.0-2.7 times higher than that of the standard shear wall.

• Journal of the Korean Wood Science and Technology
• /
• v.45 no.6
• /
• pp.846-856
• /
• 2017

The aim of this study was to develop the details of cross-laminated timber (CLT) envelops for satisfying the design standard for energy saving (DSEA) and passive standard in South Korea. When the same thickness of 180 mm concrete or CLT was used and the same materials for other layers were used for the roof, wall, and interlayer floor, the required insulation thickness for the different building envelopes in central, southern, and Jeju island was evaluated. As a result, compared to the concrete envelop, about 43 mm of insulation thickness was reduced for wall and roof with the CLT envelope. When the CLT envelopes were modified to protect the CLT from moisture based on FPInnovations (2011), the insulation thickness was further reduced by 12 mm. When the modified CLT building envelops satisfied with a passive standard are used for 10-story building, the required insulation was decreased by $40.89m^3$ for a floor ($105.27m^2{\times}2.3m$ in height) compared to concrete building. As the number of floors increases, about 3.58 m3 of insulation per floor was additionally saved.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.3
• /
• pp.440-448
• /
• 2016

As recent buildings become more air tight, the natural ventilation rate is significantly reduced and it leads to difficulty in removing accumulated moisture in buildings. Hot and humid weather in summer and the large amount of moisture caused by indoor activity are the major factors of moisture problem in Korea. The hygrothermal behavior of building environment has to be considered carefully to reduce condensation risk and mold growth potential, and comfortable indoor environment. In this study, we evaluated hygrothermal behavior of Standard Wood-frame Structure published in the Korea Rural Community Corporation Using WUFI simulation program. The results indicated that the total water contents of wood wall measured in 2014 was lower than wood wall in 2010. As a result of evaluation by separating the farming and fishing areas, Moisture problems in fishing area became larger. The walls had a significant impact on the relative humidity than the temperature each areas. Furthermore, excessive water content problem of the wood-based material was reduced in the wall that could be applied in the fishing villages by changing the outdoor finishing materials. And Mold growth risk on the interior materials could be removed through the different setting of the indoor temperature during summertime.

• Fire Science and Engineering
• /
• v.29 no.4
• /
• pp.49-56
• /
• 2015

Toxic gases from five types of interior building materials were investigated according to Naval Engineering Standard (NES) 713. The materials were plywood, indoor wall coverings (wood wall plate members and pine wood), reinforced Styrofoam insulation, laminate flooring, and PVC. Specimens were measured using an NES 713 toxicity test apparatus to analyze the hazardous substances in combustion gas from the materials. We used the US Department of Defense standard (MIL-DTL, Military Standard) to calculate the toxicity index of the combustion gas. Emissions of $CO_2$ from all specimens did not exceed the NES 713 limit of 100,000 ppm. The amount of CO gas emissions from reinforced Styrofoam insulation was 6,098 ppm. 25 ppm and 49 ppm of formaldehyde were released from the reinforced Styrofoam insulation and PVC flooring, respectively. These values were less than the limit of 400 ppm. The highest emissions were from $NO_X$ emitted by plywood and were above the limit of 250 ppm. The toxicity index of the specimens were calculated as 5.19 for plywood, 4.13 for PVC flooring, 2.35 for reinforced Styrofoam insulation, 2.34 for laminate flooring, and 1.22 for indoor wall coverings (pine wood). Our research helps us to understand the properties of these five interior materials by analyzing the combustion gas and explaining the toxicity of constituents and the toxicity index. Also, it would be useful for giving fundamentals to guide the safe use of interior materials for applications.

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.1
• /
• pp.21-32
• /
• 2019

In order to investigate the decay process of wood treated with preservative, waterproofing agent and their compound systems, a full-cell process was applied to impregnate the sapwood of poplar (Populus cathay) at paraffin wax emulsion concentrations of 0.5% and 2.0%, Copper Azole (CA) concentrations of 0.3% and 0.5%, and their four compound systems, respectively. Leaching tests and laboratory decay resistance against the white-rot fungus Corious versicolor (L.) Murrill for treated wood were carried out according to the America Standard E11-06 and China Standard GB/T 13942.1-2009. At certain time intervals during the decay test, samples were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction technique (XRD) to investigate the time-dependent changes of chemical components and crystalline structure, thus clarifying the decay mechanisms. The results suggested that white-rot fungi degrade hemicellulose and lignin in the wood cell wall first, followed by a simultaneous degradation of polysaccharides and lignin. Besides, CA could not only slower the decomposition of both hemicellulose and lignin, but also reduce the degradation amount of hemicellulose. However, paraffin wax emulsion at high concentration had a negative effect on the impregnation of CA for the compound system treated wood.

• Journal of the Korean Wood Science and Technology
• /
• v.45 no.3
• /
• pp.343-359
• /
• 2017

Many researches and policies have been carried out for saving energy in buildings. However, there are a few studies of thermal characteristics of wood-based materials that have been widely used as structural materials and finishing materials in buildings. In this study, thermal bridging areas were found to investigate thermal performance of residential building using non wood-based materials and wood-based materials. And heat transfer analysis of 16 case studies according to composition of structural materials and finishing materials was conducted. Also in this experiment, Physibel Trisco was used as the heat transfer analysis simulation tool, which conforms to the calculation method of ISO 10211. Analytical modeling was also carried out according to the ISO 10211, and the boundary temperature conditions were set at room temperature $20^{\circ}C$ and outdoor temperature $-11.3^{\circ}C$ (Seoul standard) according to the energy saving design standard in South Korea. Applied structures are classified according to the cases of concrete structure with non wood-based finishing materials, concrete structure with wood-based finishing materials and wood structure. Analyzed building elements were divided into a wall, a roof, an interlayer floor and a bottom floor. As a result, it can be confirmed that the thermal bridge of the concrete structure and wood structure were caused by the geometrical and material causes. In addition, the structural thermal bridge was caused in the discontinuity of the insulation in the concrete structure. Also it was confirmed that the linear heat transfer coefficient of the wall decreases when the wood-based materials are applied to the concrete structure.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.1
• /
• pp.75-84
• /
• 2016

Thermal performance of wooden houses used by building materials effectively contributing to building energy saving has been improved. However, the performance was decreased to the condensation and mould growth from exterior wall because the moisture control was difficult to high insulation and airtightness. Therefore, the hygrothermal performance of exterior wall, that selected 5 types of wooden houses, evaluated using the hygrothermal simulation program: heat and moisture behavior, condensation and mould growth risk. Wooden houses were selected Rural houses standard plans '10 and '14, $2^{{\prime}{\prime}}{\times}6^{{\prime}{\prime}}$ type, EIFS and wood-based passive house. And the wall A, B, C, D and E were determined by layer component of each wall. The U-value of exterior wall are 0.171, 0.172, 0.221, 0.150, $0.079W/m^2K$. The OSB absolute water content of the wall A and C was exceeds the reference value of 20%, and it was confirmed that condensation occur at insulation material inner surface through the condensation evaluation in the winter. The wall D and E showed excellent results with condensation and water content evaluation compared to others. However, mould growth risk assessment in all five types of wall had have risk. We were determined that hygrothermal performance difference of exterior wall occur the difference in the layer structure rather than in thermal performance.

• Journal of the Korean Wood Science and Technology
• /
• v.15 no.3
• /
• pp.34-43
• /
• 1987

This study was performed to find out the types of linkage of carbohydrates in wood cell walls. To study the structure of linkage of carbohydrates in wood cell walls, we have attempted to find out the method holocellulose preparation and optimum condition of enzyme hydrolysis in holocellulose, and fractionate oligosaccharide with products that hydrolized partly by acetolysis and deacetylation in holocellulose. We have achieved four results. These results as follow; 1. At first. we reacted in wood meal $NaClO_2$ 1g per lignin lg for one hour and then the same of quantity $NaClO_2$ for four hours. Through these experiments, we have developed new holocellulose preparation method which had low loss of carbohydrates and high effect of the delignification. 2. The optimum condition of enzyme hydrolysis of holocellulose which had lignin was 0.005M sodium acetate buffer (pH 5.0). We have achieved 7.2% reducing sugar through the procedure that reactioned 0.01g holocellulose putting enzyme 0.03g for 72 hours. It may be supposed that 5.5% of lignin contained in holocellulose prevented enzyme contaction from holocellulose and so this lignin has resulted in the low efficiency of enzyme hydrolysis. 3. We did not fractionated from oligosaccharides which were preparated by the method of acetolysis and deacetylation in holocellulose. The reason is that holocellulose having a lot of lignin prevented prefectly partial hydrolysis from the method of acetolysis and deacetylation. 4. We attempted analysis of six standard substances through HPLC apparatus having sugar pak 1 column which we have changed flow rate and the column temperature variably. These six standard substances were D-glucose, D-mannose, D-xylose, D-galactose and L-rhamnose, L-arabinose, But sugar pak 1 column was not fitted analysis of four substances because D-galactose, D-mannose, D-xylose, L-rhamnose were agreement with elution time. And so, we could not analize four standard substances with sugar pak 1 column.

• Journal of the Korean Wood Science and Technology
• /
• v.24 no.1
• /
• pp.68-74
• /
• 1996

Present work was undertaken to investigate the origin of milled wood lignin(MWL) in the wood cell wall using immunocytochemical techniques, which can provide the information on the localization of specific antigens(MWL in the present study) to be examined. Spruce MWL dissolved in DMSO and emulsified with Freund adjuvant was injected directly into the mouse spleen. The animals were boostered at two-week intervals after the initial immunization. Blood samples were purified in standard procedures. The characteristics of antibodies against MWL were tested by indirect ELISA. Visualization of MWL was carried out using conventional indirect immunogold-labelling methods on the ultrathin sections of spruce wood. Immuno-TEM observations showed that the immunogold probes were selectively attached to secondary cell walls of spruce wood. The most intense labelling was frequently observed in the S2 layer. In contrast, gold labelling in the lignin-rich regions, such as middle lamella and cell corner was not found. The immuno-TEM provides an indication that spruce MWL originates from the S2 layer.