• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.111-118
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• 2009

As the construction project gets bigger in scale, the actual construction itself is becoming more complex. The construction accidents occupy 26.18 percent of total death disaster according to the accidents report in 2007. It is the highest figure among the entire industry, and it shows how serious the construction accident is. In order to reduce accidents occurred in the construction industry, we should find the accident characteristics of construction workers by age. In this study, we investigated 589 cases of fatal accidents, and classified them by trades, type of works, the things that caused the accident, how they occurred, and size. We then identified accident characteristics for each group by analysing them in accordance with workers age. The result of analysis showed that in carpenter and common laborer, the number of death accidents increased as the workers age increased. Another characteristics were that the number of death accidents increased as the age increased in finishing work and reinforced concrete construction and in a smaller-scale businesses, respectively. Common labor was the trade with the highest number of death accidents and the laborers of 50 age or higher in age in finishing working type were the most vulnerable to death accidents.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.251-255
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• 1998

To elucidate the effects of a hydroelectric dam construction on annual ring growth of Pinus densiflora, the annual ring widths of 68 trees collected from 7 sites were closely examined. The result was analyzed to ask three special questions first, whether there are real effects of dam construction on the radial growth second, would the magnitude of the effect be different due to two periods of under-construction and post-construction the last, would it be different among age classes. Annual ring growth has been significantly enhanced by the dam construction. Specially, its effect was marked after the construction was finished and the reservoir was filled up with water. There was, however, no remarkable evidence that pine growth would be reduced while the dam was under construction, even though there was a minor decreasing trend. The magnitude of the effect was different among age groups. That is, the changed condition after the construction enhanced relatively the growth of aged trees monre. According to other meterological research since the dam was constructed, the reasons of enhancing pine growth assumed to be the increase of daily temperature, the decreased of daily temperature difference and the increased of rainy days.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.30-31
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• 2021

The construction industry is an industry in which skilled construction workers should be secured and trained because of the quality and productivity of buildings, but the negative image makes it difficult to supply and demand skilled construction workers. In response, this study derived the factors influencing the intention of transferring construction workers to other occupations and investigated ways to improve the prevention of leaving other occupations by age of construction workers. The factors influencing the turnover of construction workers have also been derived, and work overload, salary, workplace stability, and employment competitiveness have a significant impact on the intention of new employees to change jobs. According to a survey on ways to improve the prevention of leaving other jobs, those in their 20s and 30s are "improving working conditions, such as providing holidays, paying overtime, compliance with working hours," and those in their 50s and 60s.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.12
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• pp.51-56
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• 2018

Due to the aging of economically active population in the world, the average age of workers in the domestic construction industry is also steadily increasing. This study analyzes the aging of construction workers in small-size construction sites in Busan, where the aging of the economically active population is the most severe in Korea. As a result of the study on the aging of construction workers in six construction sites with a construction cost of less than 500 million won in Busan, it was found that 65% of the workers were over 50 years of age. In addition, several experts interviews and survey revealed that 'securing welfare facilities for construction workers' and 'diminishing prejudice about the construction industry" were the most urgent and effective methods to overcome the aging problems. The results of this study can be served as basic data to solve the aging problems in the industry.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.3
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• pp.371-380
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• 2023

Currently, as construction projects in Korea are becoming larger and more complex, the hazard rate of the construction industry is steadily increasing, contrary to other industries. This can be seen as an indication that the safety technology and safety consciousness of construction workers are insufficient compared to the improved construction technology. In addition, due to the characteristics of the construction industry based on manpower, most accidents appear in conventional forms such as fall and trip due to human errors. Therefore, analyzing the relationship between the characteristics of human resources and accidents and establishing detailed safety plans is an essential part of reducing construction accidents. In this study, a correlation analysis was conducted using 62,805 cases of construction accident cases over 3 years to derive the characteristics of accident occurrence focusing on the age of workers. As a result of the analysis, the relationship between the age of workers and the frequency and severity of accidents for each accident type was derived, focusing on the top 10 accident types.

• Korean Journal of Occupational Health Nursing
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• v.27 no.1
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• pp.48-58
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• 2018

Purpose: The purpose of this study was to understand the present status of the work performance of the construction industry health managers and the developmental direction for the construction industry health management. Methods: The subjects of this study were 149 health managers working in the construction industry. Data of a total of 130 participants were analyzed by excluding the missing data among field workers. The contents of the survey were the characteristics of the workplace, the difficulties and requirements of health management, and the level of job performance. Results: The factors affecting measuring work environment task were age, number of workers, number of safety managers, and lack of support from the headquarters. The factors affecting managing work environment and physicochemical harmful factors were age, type of contract and conflicting business opinions. The factors affecting implementing health examination were age, type of contract, and number of safety managers. The factors affecting healthcare were age, type of contract, number of safety manager, presence of healthcare room, and conflicting business opinions. Conclusion: It is necessary to provide practical guidance and practical resources, and education for strengthening capacity. The support for business owners and managers support is needed.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.393-400
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• 2013

Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05b
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• pp.51-52
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• 2010

In this study, it is confirmed that the use of equivalent age method can be applied to predict the early-age strength in case of using the new early strength concrete developed for the reduction of construction work period by our company, in apartment.

• Journal of the Korea Institute of Building Construction
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• v.12 no.1
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• pp.87-97
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• 2012

This paper presents a method of estimating the setting time of cement mortar incorporating recycled aggregate powder (RP) and cement kiln dust (CKD) at various curing temperatures by applying an equivalent age method. To estimate setting time, the equivalent age using apparent activation energy (Ea) was applied. Increasing RP and CKD leads to a shortened initial and final set. Ea at the initial set and final set obtained by Arrhenius function showed differences in response to mixture type. These were estimated to be from 10~19 KJ/mol in all mixtures, which is smaller than those of conventional mixture ranging from 30~50 KJ/mol. Based on the application of Ea to Freisleben Hansen and Pederson's equivalent age function, equivalent age is nearly constant, regardless of curing temperature and RP contents. This implies that the concept of maturity is applicable in estimating the setting time of concrete containing RP and CKD. A high correlation was observed between estimated setting time and measured setting time. A multiregression model was provided to determine setting time reflecting RP and CKD. Thus, the setting time estimation method studied herein can be applicable to concrete incorporating RP and CKD in the construction field.

• Journal of the Korea Institute of Building Construction
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• v.14 no.4
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• pp.322-328
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• 2014

In this study, revelation performance of concrete at early age according to types of cement, water reducing ratio of high performance superplasticizer and mixing of accelerator for early hydration was examined aiming for reduction of construction period of framework through securing strength at early age of concrete. It was observed that strength at early age, 5MPa in 12hours, 14MPa in 18hours, is secured by early strength improvement type cement and using promotion admixture for early hydration which are Sodium persulfate, Potassium hydroxide. Therefore cost reduction is expected to be possible in construction site by reducing construction period of frame work.