• Journal of the Korean Institute of Rural Architecture
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• v.23 no.1
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• pp.1-8
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• 2021

In this study, a real-sized experimental equipment (pilot plant) was built at the site based on the preliminary research data to develop a movable separator for the mixed construction waste that can be implemented in agricultural areas to review its feasibility through the evaluation of its separation efficiency by waste types. The final construction of the movable separator and experimental results of the separation efficiency are summarized as follows. 1) The separation performance according to the blade type was the best for the combustible wastes either with 26 numbers of L-type blades and 32 numbers of pin type blades. As far as combination of blade types, when the L-type and pin-type were combined, the best separation efficiency was achieved. 2) The separation efficiency for waste wood by the conveyor type and angle of inclination (slope) of the trommel was the best when the conveyor had ribs of seagull shape with the angle of inclination 45°. 3) The separation efficiencies by process showed that 65.9% was separated as inorganic demolition wastes, 18.2% as waste woods, and 16.0% as combustible wastes at conveyor speed of 2-3 rpm, and the error rate was the least from the waste types generated in the dismantle site.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.371-378
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• 2016

In this study, a small portable sorting pilot for separation that can be used in dismantling construction site, which is the stage of construction waste generation, was developed, and its separation efficiency was evaluated to increase the actual recycling rate of the construction waste. The pilot was developed as portable sorting pilot for separation of 6 ton capacity that can handle one arm roll box within a $15m^2$ area in consideration of narrow places in the downtown area where a number of dismantling sites are located and various processes performed in the dismantling sites. In order to evaluate the efficiency performance of the developed device, the separation and sorting were carried out ten times with respect to trommel rotational speed RPM 2-3, 4-6 and 7-8. According to the results, the highest efficiency of about 90% was shown at RPM 6-7.

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.537-545
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• 2016

In order to cope with the new and strict government regulations for turbid water discharge from construction sites, this study tested whether synthetic fiber filters can replace conventional best management practices. The filter efficiency was about 10 to 60% with a varying filter depth of 5 to 15cm, presuming extreme storm flow conditions to be in the range of 800 to 1500m/day of filtration rates. Fiber filter acts exactly like a granular filter, i.e. the separation efficiency is directly and inversely proportional to filter depth and rate, respectively. Based on the operational data, we suggested the Log-Log design relationship, which can be used to determine the filter depth and area. Compared to the widely used gravel filter which treats the turbid water at the construction site, about 20% higher efficiency was obtained under similar operating conditions. Cleaning the filter through a simple hand-washing method at the time of break-through, achieved about 90% soil recovery.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.9 no.1
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• pp.8-14
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• 2013

HVAC&R systems are the most energy consuming building services representing approximately half of the final energy use in the building sector. Despite their significant energy use, there is a lack of a consistent and homogeneous framework to efficiently guide research, mainly due to the complexity and variety of HVAC&R systems but also to insufficient rigour in their energy analysis. This research reviews energy consumption of HVAC&R systems with the aim of establishing a common idea for the analysis of energy efficiency. The paper focuses on energy flow of the HVAC&R which include air-conditioning, transport and heat generation system for low-energy buildings.

• Explosives and Blasting
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• v.22 no.3
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• pp.65-70
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• 2004

Lately, the length of tunnel, the number of long-large tunnel over 3 lanes are steeply increased because of the request for high-speed and straight road. Therefore, the maximization of excavation efficiency is needed in tunnel construction. The sapaesan tunnel (4 lanes with the length of 4km) construction was delayed with environmental conflict far 2 years. For making-up delayed construction period, various new methods were adopted to improve excavation length, look-out and blasting efficiency. This study introduced bulk explosive which is new method in tunnel blasting and verified the efficiency of bulk explosive far long-large tunnel.

• Journal of Environmental Science International
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• v.14 no.8
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• pp.785-792
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• 2005

In order to reduce roadside and indoor air pollution for volatile organic compounds VOC), it may be necessary to apply photocatalyst-coated construction materials. This study evaluated the technical feasibility of the application of $TiO_2$ photocatalysis for the removal of VOC present in roadside or indoor air. The photocatalytic removal of five target VOC was investigated: benzene, toluene, ethyl benzene and o,m,p-xylenes. Variables tested for the current study included ultraviolet(UV) light intensity coating materials, relative humidity (RH), and input concentrations. Prior to performing the parameter tests, adsorption of VOC onto the current experiment was surveyed, and no adsorption was observed. Stronger UV intensity provided higher photocatalytic destruction(PCD) efficiency of the target compounds. For higher humidity, higher PCD efficiency was observed. The PCD efficiency depended on coating material. Contrary to certain previous findings, lower PCD efficiencies were observed for the experimental condition of higher input concentrations. The current findings suggested that the four parameters tested in the present study should be considered for the application of photocatalyst-coated construction materials in cleaning VOC of roadside or indoor air.

• Journal of the Korea Institute of Building Construction
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• v.14 no.1
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• pp.1-10
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• 2014

The SC structure can have relatively liberal sectional surfaces, and allows modularization for pre-forming in factories and structural stability. It can be used for the shear walls in the core of general buildings or the structural members for parking buildings. In the future, it could be applied to moving large bus terminals, and widely used for general industrial structures as it can expedite the process compared to other methods. This study examined the applicability of SC structures to the retaining walls of a parking building and reviewed its economic value by comparing its construction term, quality control benefits, and cost compared to RC structures. It was found that SC structures are about 1.6-1.7 times more expensive than RC structures in terms of the cost of fabrication and installation. However, the construction term can be reduced by 27% to save indirect costs for constructors, as well as the cost of removing molds and material loss required when installing RC structures.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.385-388
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• 2002

The construction industry has complicated production processes with diverse disciplines and subcontractors, which is the major cause of lowered productivity. To solve this problem, multi-trade subcontract system is recently suggested. Some general construction companies have applied this method to some sections of work process. However, this is in the early stage of application. The purpose of this study is to define an integrated contract package for improving both contractor and subcontractor efficiency. First, this study recognizes construction company to need of multi-trade subcontract system. Finally, it suggests feasible activities which can be useful for a construction company to apply to this subcontract system.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.483-486
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• 2006

The value engineering(VE) in construction projects is systematic method which improve quality as well as reduction input cost and as construction VE work extends the range of application, the importance is rising. For this reason studies are needed to enforce design value engineering work systemically and effectively. In this study, we analyzed the problem of the present construction VE processing and deduced the model to be most suitable the work efficiency. As suggested model reflects systemically requirement item of owner and user, it will make approaching direction and standard establishment possible. So it will increase the following function analysis in analyzing step and the effectiveness of creating idea and make successful VE result.

• Korean Journal of Construction Engineering and Management
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• v.3 no.2 s.10
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• pp.87-98
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• 2002

Korea government is making an effort to improve the efficiency in construction industry by introducing CITIS (Contractor integrated Technical Information Service). In order to provide a base for the application of CITIS into the construction industry, this research provides a concept of virtual factory which should be incorporated into CITIS system for the successful collaborative work in the virtual space. It then implements a prototype system through process and data modeling to apply into the road construction projects. The prototype system is tested to verify its efficiency. Finally, lesson learned from these works is provided to advance the current CITIS toward a collaborative virtual factory.