• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.05a
• /
• pp.27-28
• /
• 2013

This study investigates the effect of a protective layer on the level of carbonation resistance of concrete. For the protective layer, a PE film, bubble sheets, double layered bubble sheets and styroform were placed in a mold before placing the concrete. In addition, PE film was retrofitted by attaching on the surface of the substrate concrete with a glue. Results showed that the carbonation depths of the control concrete were 4.6 mm and 5.2 mm at one week and two weeks exposure in an accelerated carbonation chamber, whereas the concrete with all types of protective layer except PE flim did not allow the ingress of carbon dioxide during the same period.

• International conference on construction engineering and project management
• /
• 2015.10a
• /
• pp.349-352
• /
• 2015

Size of building has a direct relationship with building cost, energy use and space maintenance cost. Therefore, minimizing building size during a project development is of paramount importance against such wastes. However, incautious reduction of building size may result in crowded space, and therefore harms the functionality despite the fact that building is supposed to satisfactorily support users' activity. A well-balanced design solution is, therefore, needed at an optimum level that minimizes building size in tandem with providing sufficient space to maintain functionality. For such design, architects and engineers need to be informed accurate and reliable space-use information. We present in this paper a conceptual framework of an agent-based space-use prediction simulation system that provides individual level space-use information over time in a building in consideration of project specific user information and activity schedules, space preference, ad beavioural rules. The information will accordingly assist architects and engineers to optimize space of the building as appropriate.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.6
• /
• pp.105-112
• /
• 2014

The objective of this study is to examine the relationship between the degree of business diversification of a construction company and two of the indicators that represent financial stability, namely, a current ratio and a debt ratio, in order to draw policy implications. The current ratio and the debt ratio were used as variables that represent financial stability of a construction company. Berry-Herfindahl Index was used to measure the degree of business portfolio diversification of a construction company. For the analysis, quarterly time series data were retrieved from the financial information disclosure system of Korea's Financial Supervisory Service for the period between the first quarter of 2001 and the third quarter of 2013. The analysis results showed that a higher current ratio and a debt ratio led to a greater extent of business diversification. A higher level of business diversification led to a higher current ratio and a lower debt ratio. It was also shown that the impact of business diversification on the current ratio and the debt ratio outweighed the impact of changes in the current ratio and the debt ratio on business diversification. Meanwhile, an increase in the level of business diversification showed a quite positive effect as it raised the current ratio and lowered the debt ratio of a construction company. These findings suggest that diversification of business portfolio is essential for construction companies to strengthen their financial stability.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.5
• /
• pp.322-333
• /
• 2019

The purpose of the current study was to investigate the level of market size and market share of domestic research equipments for analyzing the difference of the number and amount of construction by the manufacturing countries in the basic and analytical science fields based on the information of the research equipment invested by the Korean government for the past 14 years. As of January 1 2019, from 2005 to 2018, 20,687 research facilities & equipments (main equipment with a construction cost of 30 million won or more) built in the basic and analytical science fields were selected for this study and their components, standard classification, number of construction, and amount of construction by country of manufacture were analyzed. Differences of the number and amount of construction among manufacturing countries were tested using a single sample chi-square test and one-way analysis of variance, followed by Bonferroni's post-hoc test. As a result of this study, the number of construction (p<.001) and construction amount (p<.05) were statistically different for each manufacturing country. The level of market size and market share was significantly different according to the equipment standard classification (p<.05). Therefore, differentiated strategies of the government and policy research projects will be required for each type of equipment and amount in order to support the policy for the localization of research equipment.

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.3
• /
• pp.122-133
• /
• 2019

In the construction industry, bidding competitiveness is the most basic and important competence of the company. Bidding competitiveness comes from competitive advantage, but the strategy of the company to capture bidding competitiveness varies with the characteristics of the project. In particular, overseas construction is where uniqueness of the construction industry and the specificity of international business coexist. This study analyzes the bidding success ratio and the level of bidding difficulty by project characteristics with 12,952 overseas construction bidding cases. Consequently, it was found that the bidding success ratio of Middle East and North Africa (MENA) and civil engineering was the lowest in each group of project characteristics, and therefore the level of bidding difficulty is high, respectively. In addition, it was confirmed that the bidding success ratio of small size or short duration project was relatively high, and the bidding success ratio of both the negotiated bidding in the bidding method group and the private sector in the client type group was respectively high. However, Kruskal-Wallis test in contract type and period shows that there is no statistically significant difference in the bidding success ratio by group.

• Korean Journal of Construction Engineering and Management
• /
• v.23 no.5
• /
• pp.3-14
• /
• 2022

Construction projects have high potentials of claims among a variety of stakeholders. Claims on their own are not disputes but they have high potentials leading to disputes if agreements are not made between parties due to conflicting opinions. In the event of the construction disputes between clients and contractors, it could give negative impacts to both parties and, to minimize or pro-actively manage construction disputes, the role of clients is more significant. The objective of the study is to analyze a level of associations between the types of disputes and causes of construction projects based on the association rule analysis, and to identify and discuss key characteristics and implications from client's perspectives. The study analyzes associations between the types of disputes and causes, and also identifies those with a high level of associations. It also presents the outcomes of more systematic analysis compared to descriptive statistics just based on frequencies. Through the analysis of the data cases, the study proposes the directions to resolve the causes of disputes from client's perspectives. It can assist to improve understandings of the relationships between the types of disputes and causes and to pro-actively manage the disputes of construction projects.

• Korean Journal of Construction Engineering and Management
• /
• v.23 no.3
• /
• pp.36-44
• /
• 2022

This study analyzed Corporate Social Responsibility (CSR hereafter) of construction companies, especially focusing on small-medium companies. Surveys on construction companies' CSR activities and intensive interview with experts were executed to analyze and draw some implications. The empirical results shows that most of construction companies feel keenly necessity of CSR. The level of small-medium companies' awareness is lower than that of large companies'. CEO and board members of small-medium companies are less concerned about CSR yet. Carrying CSR activities co-working with NGO is preferred because of expertise and network. This study also suggests future strategy for CSR in the construction industry, focusing on small-medium companies. First of all it is necessary for small-medium companies to enhance the level of awareness and encourage participation in CSR. Second, it is required to strengthen relation with NGO and share information for CSR. Third, it is really significant to strengthen budget support and secure personnel to activate CSR. The systematic support by gevernment is also important. Lastly, it is essential to mount a publicity campaign and develop various CSR program. The role of 'Construction Industry Foundation for Social Responsibility' is emphasized because small-medium companies have very little room for CSR.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.2A
• /
• pp.93-102
• /
• 2010

The numerical analysis and safety assessment by construction stages were considered the essential examination particular in order to solving the unstability of long-span bridges in the middle a construction. When estimating structural response characteristics by the construction stage analysis of long-span bridges, the influence of the near-field ground motion (NFGM) would be evaluated as a critical factor for the seismic design because it indicates clearly different aspects from the existing input earthquake motion data. Therefore, this study re-examined the response aspect of long-span bridges considering NFGM characteristics based on the response spectrum result, and advanced the presented numerical analysis program by the related research for conducting the construction stage analysis and reliability assessment of long-span bridges efficiently. The excellency of various construction schemes was assessed using the time history analysis result of critical member considering NFGM characteristics. For evaluating quantitative safety level, the reliability analysis was conducted considering the influence of external uncertainties included in random variables, and presented the safety index and failure probability of the critical construction stage by NFGM characteristics. In addition, the reliability result was examined the influence of internal uncertainties using monte carlo simulation (MCS), and assessed the distribution aspect of the essential analysis result. It is expected that this study will provide the basic information for the construction safety improvement when performing seismic design of long-span bridges considering NFGM characteristics.

• Journal of Korea Water Resources Association
• /
• v.33 no.1
• /
• pp.51-59
• /
• 2000

A dynamic model, which combined time series model with distributed-lag model, is applied to understand the relationship between rainfall and groundwater level. In the model, rainfall with distribution lags and past groundwater level as a dependent variables were used to estimate present groundwater level. The distribution of the lagged rainfall effects for groundwater levels was modeled by Almon polynomials. The model was applied to Banglim and Tanbu groundwater stations in Pyungchang river and Bocheong stream watershed which are representative basins for International Hydrological Program (IHP). The dynamic model represents observed groundwater levels very well and can be used to predict the levels. The model parameters reflect hydraulic characteristics of aquifer. In addition, from the parameters it appears that the increase in groundwater level due to rainfall takes place significantly within first two days of the rainfall event. The rainfall of the order of 18mm/day and 30mm/day at Banglim and Tanbu, respectively, had no significant effect on the groundwater levels.

• Korean Journal of Construction Engineering and Management
• /
• v.12 no.2
• /
• pp.101-110
• /
• 2011

Because bridges can cause more significant damage than other infrastructure a certain level of safety shall necessarily be secured for users. As most of bridges' service life become 20-30 years there will be a dramatic increase in the maintenance and repair cost but the budget and human resource will be limited. Asset management technique can help the efficiency in maintenance and budget management with the limited resource. For its application, there must be a way to evaluate how bridges provide service to users. The level of service can be quantified by a performance measure. This study introduces performance measures and an evaluation process for the determination of level of service. The evaluation results will be used as a fundamental information in the determination of maintenance/repair/management targets and in the decision making process of the bridge asset management.