Performance assessment of existing Korean school building, 1: Mechanical and physical properties of the rafter members
2009
Kim, G.C., Chonbuk National Univ., Chonju (Korea R.) | Kang, C.W. | Matsumura, J.
Many potentially valuable wood residues from buildings are ending up as broken-up waste destined for the landfills in Korea. This practice is a significant economic loss. An accurate estimation of residual capacities of the lumber found in older structures is required prior to the promotion of the reuse and recycle ratio. For this purpose, precursor studies are required on the accurate assessment of residual capacities according to time for typical construction species used in Korea. The case study for this current research is the rafter members of the Iksan National College Educational Building in Korea. The age of the rafter members is estimated to be 50 years. Hundred and ninety-six sample specimens were visually divided into two groups according to annual ring and cross-section features. From the results of this study, the following conclusions have been made: 1. The moisture content of group 1 was found to be slightly higher than that of group 2. In the case of oven-dried density, the averages between the two groups were almost the same. 2. The strength values of group 2 were all higher than those of group 1 with the exception of shear strength. It is assumed that the domestic major construction species is a type of hard pine according to the obtained physical and mechanical properties, and visual characteristics. 3. The main fracture mode of group 1 is that of cross grain tension. In the case of group 2, the fracture modes are distinguished by a mixed mode rather than by one type of mode. Failure types for compressive strength are all of a crushing failure type with the exception of the splitting failure type for specimen 7 in group 2. 4. There were no significant differences between the two groups in terms of mechanical properties. However, there was an obvious visual difference between the two groups.
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