• Composites Research
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• v.19 no.2
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• pp.35-41
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• 2006

FRPs have been used widely and demonstrated in the field of aero industries etc., and began to be used as new construction materials of civil structures. Pre-stressing tendons, reinforcing bars etc. are all examples of the many diverse applications of FRP in new structures. Especially, 40 of all-FRP bridges were reported. The reason why FRP composites were used fur construction materials of civil structures, has been that the working time and the cost of maintenance can be reduced because of the effect of their lightness and durabilities. The purpose of this paper is to report the examples of the many diverse applications of Fiber Reinforced Plastic in construction materials of civil structures.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.120-121
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• 2021

This study examines the performance of the pre-treatment process system to use CGS, a by-product generated in IGCC, as a concrete fine aggregate for construction materials, on the quality of CGS fine aggregate. As a result of the analysis, it is judged that the quality of fine aggregates of CGS can be improved at both density, absorption rate, and 0.08mm body passage amount after the hydroelectric screening process using water as a medium during the pretreatment process. It is believed that it can be used as basic data for national standard certification of CGS fine aggregates in the future.

• The Journal of Engineering Geology
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• v.23 no.1
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• pp.67-77
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• 2013

We conducted a Tunnel Seismic Prediction (TSP) survey in a spillway tunnel at Juam Dam to predict the locations of major discontinuities ahead of the tunnel face. We compared the results of the TSP survey with those from pre-construction inspections (including a surface resistivity survey and borehole investigations) as well as with direct tunnel-face mapping during excavation. The TSP method predicted the locations of major fracture zones that were unnoticed in the pre-construction inspections. The reinforcement patterns planned on the basis of pre-construction inspections were changed on the basis of the TSP results. The results demonstrate that TSP surveys are a cost-effective and reliably accurate method of predicting the locations of fracture zones. Although the TSP method has some limitations, these results suggest that the method is generally useful for predicting geological conditions prior to tunnel face construction.

• Journal of the Korean Geotechnical Society
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• v.29 no.1
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• pp.71-80
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• 2013

Before and after the test constructions, and after an 11-month hiatus from the pilot pile installations, the in-situ tests (CPT, SPT) were carried out at the ground adjacent to the noise- and vibration-free screw concrete piles installed by 2 kinds of construction methods (i.e., the toe-jetting shoe type, the pre-digging type). In the toe-jetting shoe type construction methods, after construction, the soil strength within 3.5D (where, D = pile diameter) from the pile center decreased greatly by about 46% of the original ground and, after an 11-month hiatus, a strength recovery adjacent to the piles appeared about 71% of the original ground. In the pre-digging type construction methods, a strength recovery adjacent to the piles appeared 100% of the strength of the original ground.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.121-128
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• 2000

Landfill and lysimeter experiments were conducted to estimate the optimum air injection method for the degradation of waste in landfill and the pre-stabilization. Continuous injection with low pressure and quantity can be effective for pre-stabilization of old landfill due to the lower contents of volatile solids in landfill. Air injection and landfill gas (LFG)extraction showed that the SVE (Soil Vapor Extraction) effect by air ventilation was more significant than the biodegradation of organics. Theses results suggested that they could accelerate the biological stabilization of organic waste in landfills. It is also expected that they would reduce the problems including gas emission during the landfill mining, separation and/or transportation to such levels that might be discharged directly to the atmosphere or with minimal treatment, if required.

• The Journal of the Korea Contents Association
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• v.12 no.8
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• pp.373-379
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• 2012

Public construction projects are implemented by government or public agencies using public resources to enhance the welfare of the people. Therefore, this paper investigates the impact factors for public construction performance. Then, the weights for impact factors are assigned using AHP. The impact factors are categorized into construction policies, project management efforts, and project environment. Further, 16 detail impact factors are listed in each category. The results show that weights are ordered in appropriate budget, reasonable project implementation process, and pre-project planning. These impact factors are related with pre-construction management activities. However, construction related impact like procurement, work difficulty, and construction environment show relatively low weights. The results can be useful to improve construction performance with managing impact factors showed high weights.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.234-237
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• 2003

The Korean housing supply have been provided by the Pre-construction sales system. The Pre-construction sales system contributed to large housing supply. But it followed by the market anomaly. Along the housing market is changing to tile market for consumers, it requires new policy and regulations. This market changes and needs to modify the policy make a discussion about introducing the Post-construction sales system. it concerns to change the time to sale. This paper analyzes the present feasibility study and makes a tool to predict construction cashflow considering changed sales point. The sales timing leads to decide the amount of financial costs in the construction project and that cost affects to the feasibility. The accurate cashflow prediction is required for a successful apartment construction delivery.

• The Journal of Economics, Marketing and Management
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• v.12 no.2
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• pp.11-18
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• 2024

Purpose: The purpose of this study is to suggest the activation plan of the post-construction sales through the results of a survey on the perception of Seoul citizens and experts. Research design, data and methodology: The purpose of this study is to suggest the activation plan of the post-construction sales through the results of a survey on the perception of Seoul citizens and experts. Results: According to a survey of Seoul citizens' perceptions, 76.7% of Seoul citizens were well aware of post-construction sales and recognized that post-construction sales would reduce pre-sale speculation and confusion in the real estate market. Second, 73.6% of Seoul citizens were willing to buy houses through post-construction sales, and third, 79.6% of Seoul citizens recognized that a post-sale system was necessary. Experts' opinions generally responded to the expansion of the introduction of post-construction sales, saying, 'It is necessary for both the public and the private sectors'. Second, while experts say that there are also positive effects, negative effects such as polarization centered on large corporations, an increase in sales prices, and a decrease in housing supply are also concerned. Third, experts responded that 'diversification of financing methods' is the most important task in revitalizing the post-sale system. Conclusions: The policy implications are that it is necessary to mandate the post-construction sales in the long term, and that the quality assurance system needs to be supplemented even if the sale is promoted post-construction sales. In addition, private participation is essential to revitalize the post-construction sales, and government support such as initial financing, low-interest rates, and various financing measures should be sought to expand private participation.

• Journal of Construction Engineering and Project Management
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• v.8 no.2
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• pp.17-33
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• 2018

This study investigates the stability of professionals' cost variability factor-rankings across different levels of cost-variability and response scenarios. Descriptive statistics are used to examine the stability of factor-ranking for 20 cost variability factors and a Multinomial Logistic (MNL) regression model was implemented to examine the stability of cost variability factors across three cost variability levels. The finding on the descriptive statistics indicated that professionals' factors-rankings are stable only for external factors. The MNL regression results on factor-stability suggested that 8 out of the 20 evaluated factors were unstable determinant of lower cost variability levels. These factors are "risk associated with the project", "personal bias and poor professionalism of the estimators", "limited time available to complete the project", "lack of skills and experience by estimator" "geographical location of projects", "incomplete & rush designs for estimate", "unforeseen or unexpected site constraints", "high class bidders for the contractors". Similarly lack of experience and large size projects were observed to be unstable as well. These observations suggest that professionals' view on pre-tender cost variability factor-ranking yields unstable factor rankings hence should not be relied upon as the only mechanisms to mitigate cost related risks in construction projects.

• Journal of the Korea Institute of Building Construction
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• v.8 no.3
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• pp.85-91
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• 2008

Out of all the nondestructive test (NDT) methods, the pullout test is one of the most reliable techniques for estimating the strength of concrete under construction. However the pullout test inevitably produces significant surface damage because of the inherent test mechanism and costs too much for using measurement devices. In the view of construction engineers and inspectors, the main purpose of NDT methods for concrete is to verify whether the concrete strength of structure members exceeds the target strength or not. In this paper, a new pullout test method, which involves a pre-installed breaking bolt, with pre-determined breaking torques corresponding to the target strength of concrete, is introduced with related test data. The three types of test, the rebound hammer test, the pullout test, and the new pullout test with breaking bolt, were carried out on wall specimen with three types of concrete strengths. Our results show that concrete strength as evaluated by the pullout test with breaking bolt was similar with cylinder test results. Therefore it can be said that the new pullout test with breaking bolt is a useful method for checking the concrete strength without any surface damages in construction site.