• Explosives and Blasting
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• v.25 no.2
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• pp.47-60
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• 2007

The blast demolition technology has been used to demolish various industrial facilities and tall buildings since 1950s in the advanced countries such as USA and U.K. It is now considered as one of safe demolition methods in the above countries. In Korea, several companies have tried to introduce blast demolition technology in the early days of the 1990s. However, this technology is still at the beginning stage and not fully adopted due to situation of avoiding technology transfer by overseas technical tie-up companies, lack of objects to be demolished and low level recognition on blast demolition. This technology shall be considered as a cutting edge technology to be applicable to demolition of skyscrapers, various industrial structures and factory buildings in the near future. Blast demolition of a pier structure was carried out under the site condition where there were already the constructed 2 pier structures of up and down line which had safety problems in an expressway construction project. The pier structures need to be demolished and reconstructed for a short period of time in consideration of the construction work process to be followed.

• Land and Housing Review
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• v.2 no.4
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• pp.397-406
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• 2011

This research aims to develop various infill-systems for practically applying to long-life housing with 100-year durability and flexibility as a strategy for realizing sustainable residential environment. Especially, the developed infill-systems & technologies were concentrated to the mock-up house applied with the standard model of long-life housing, and their in-situ applicability by a phase, experts' consultation, and questionnaire survey were also evaluated. This research was executed to divide by 3 phases. In the First phase infill-systems for a housing unit of $84m^2$ exclusive use area as well as a support of whole structure and infill-systems including dry wall, and windows were constructed, and their in-situ applicability were evaluated. In the Second phase vertical integration of upper and lower housing units of $50m^2$ and $40m^2$ exclusive use area was investigated the first in domestic for 3 housing units of $50m^2$ exclusive use area. In addition, various infill-systems including the horizontal expansion of $50m^2$ and $10m^2$ exclusive use areas were also constructed and evaluated on their in-situ applicability. In the third phase diverse performance tests and field investigation for in-situ verifying of dry Ondol, developed this research, were executed to improve their practicability. Inner dry walls were taken apart, moved and re-constructed for verifying their practicability to investigate 3R-Reduce, Reuse and Recycle-realization too.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.6
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• pp.751-762
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• 2022

Welded head studs are mainly used as shear connectors to bond steel girders and concrete slabs in steel-concrete composite bridges. For welded shear connectors, environmental problems include noise and scattering dust which are generated during the removal of damaged or aged slabs. Therefore, it is necessary to develop demountable shear connectors that can easily replace aged concrete slabs for efficient maintenance and thus for better management of environmental problems and life cycle costs. The buried nut method is commonly studied in relation to bolted shear connectors, but this method is not used in civil structures such as bridges due to low rigidity, low shear resistance, and increased initial slip. In this study, in order to mitigate these problems, a demountable bolted shear connector is proposed in which the buried nut is integrated into the stud column and has a tapered shape at the bottom of an enlarged column shank. To verify the performance of the proposed demountable stud bolts in terms of static shear strength and slip displacement, a horizontal shear test was conducted, with the performance outcomes compared to those of conventional welded studs. It was confirmed that the proposed demountable bolted shear connector is capable of excellent shear performance and that it satisfies the slip displacement and ductility design criteria, meaning that it is feasible as a replacement for existing welding studs.