• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.29-30
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• 2022

Tile defects in apartment houses are caused by a combination of various factors. These factors cannot be specified, and it is difficult to determine the exact cause because a number of causes are intertwined. In addition, because the climate of Korea is different by season, the coefficient of thermal expansion between materials is different, which is a major cause of tile defects. Therefore, this study analyzed the difference between the construction location and the period of defect occurrence according to the types of tile defects caused by environmental differences between indoor and outdoor environments. Two-way ANOVA was used, indoor and outdoor spaces were selected, and defect types were selected accordingly to show the difference in the occurrence period of each defect.

• Korean Journal of Construction Engineering and Management
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• v.16 no.2
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• pp.21-28
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• 2015

Construction defects are major components that result in cost overruns and schedule delays in construction projects. There have been extensive research efforts to investigate the cause of defects. However, little effort has been devoted to analyze correlation among various reasons of construction defects while a defect is not usually an outcome of a single cause, but rather occurs when several interrelated causes combine. Based on this recognition, this paper analyzes 831 nonconformity reports collected from 30 construction projects in Korea from 2011 to 2014. The correlation analysis revealed that a significant portion of construction defects occurred in the procurement and construction phase and as the pattern of function defect and installation defect. Triggered by human error, defective material and faulty method, these defects are treated by conccession, repair, rework that can significantly lower the cost and schedule performance. This paper is significant in terms of providing a theoretical basis for analyzing correlation among various reasons of construction defects and quantitative measures for establishing effective defect prevention strategies.

• Korean Journal of Construction Engineering and Management
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• v.6 no.3 s.25
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• pp.128-134
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• 2005

Up to now, the various water proofing methods and materials have been developed. For the water proofing methods, poly-urethane membrane method is one of the commonly used and increase market share in water proofing industry due to it's many advantages. However, in spite of it's many advantages over other water proofing methods, water proofing defect occurs frequently. With this respect, the study investigate water proofing defect causes in roof water proofing. The study investigate 13 water proofing construction site in Sunchon city in oder to find urethane membrane defection causes and their type. As a results of the study, the followings are founded. 1) Among various water proofing defection causes, problems of water remain phenomenon due to surface horizontal level defect which occupy $25\;\%$ of total defect causes is the most commonly occur. 2) The second defect cause which occupy $15\;\%$ of total defect causes is the swell up phenomenon due to surface dry problem. For the prevention of water proofing defection in roof using urethane membrane, the followings are recommended. 1) Faultless surface treatment before using urethane membrane 2) Develop improved urethane membrane material 3) Improve urethane membrane construction technique

• Journal of the Korea Institute of Building Construction
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• v.7 no.4
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• pp.125-132
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• 2007

The use of Self-Leveling material is increasing recently. This paper assesses the quality of surface layer of concrete floor when Self-Leveling material is defective. The paper shows how to predict the defect of SL material before construction begins. The relationship between the quality of surface layer of concrete floor and the defect of SL material was determined and the quality of surface layer of concrete floor was then estimated. The relations between the quality of surface layer and the defect of SL material were determine considering surface strength, moisture, and consistency of surface layer. Absorbing amount was used as the indicator of consistency and the absorbing amount of test material was measured. Then the relations between the test material and surface strength were determined. Generally concrete floor with greater consistency has greater surface strength, however in this study, we hound that high impact concrete floor could have lower surface strength as the consistency gets bigger. The relations between the level of defect occurred in SL material and the quality of surface layer were examined and we clarified that the surface layer with lower consistency gets higher possibility to occur exfoliation in early stage, one or two weeks after constructing SL material. When the consistency is sufficient, the occurring situation of defect depends upon the moisture of surface layer. Little amount of moisture gets higher possibility not to occur the defect. As the amount increases, fissure generates and early exfoliation may occur. In addition, the level of fissure is highly related with the surface strength.

• Journal of the Korea Institute of Building Construction
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• v.20 no.4
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• pp.357-365
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• 2020

While numbers of apartment housing are continually rising in the domestic housing construction industry, apartment contractors are currently developing plane models, upgrading facilities, and relevant technology, and investing much efforts to meet the higher demands of consumers. However, the construction process of apartment housing involves the intricate properties of the construction industry such as materials, workforce, equipment, weather, and unpredictable situations. If any of these factors becomes discordant and results in interference and interruption of the construction process, then defects, both functional and aesthetic, are likely to occur due to errors in the plan of industry organizers and constructors. Therefore, this research identifies the types of defects in an apartment construction project and analyzes their relative importance. Firstly, this research reviews the previous research trends and will reduce the needs of this research. Afterward, defect repair costs corresponding to the different defect types are calculated by applying results of the research and performing frequency analysis on defect types included in 'Tenant preliminary research' on apartments constructed by Company A. As a result of analyzing the importance of defect type, the top six activities, including tile, floor, paper hanging, PL window, cabinetry, and kitchen cabinet, are found to be of high importance, and the top six activities in question need of repair and management of defects first. The results of this study will help establish a plan to initially respond to such problems as refusal to move in and filing a defect suit against delay in repairing defects.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.200-201
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• 2021

According to the dispute cases filed for claiming the collective defect repair fees, inter-layer concrete joints turned out to be the most frequently disputed item. For this reason, this study selects the inter-layer concrete joints to further analyze the primary causes and details of each dispute case. From the results of this study, three primary causes of the disputes are found, which are 1) the absence of standard specifications for construction quality control and management after construction; 2) the absence of established standards for repair when construction defects are found. In order to prevent construction defects in inter-layer concrete joints, this study provides three suggestions including 1) the current standard specifications for inter-layer concrete joints should be further specified by the Ministry of Land, Infrastructure and Transport; 2) a construction defect should be judged according to the compliance to the standard specifications; and 3) a clear and institutional protocol needs to be established for defect repair in cases that new public apartment houses have been judged to have defects.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.337-338
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• 2023

As the number of defects in apartments has increased recently, lawsuits and disputes related to defects have also increased. As a result, the loss of time and money is enormous. Therefore, fundamental measures are needed to reduce the occurrence of defects. Therefore, the purpose of this study is to propose a plan to reduce defects, focusing on window construction. To this end, existing studies were reviewed, and data from domestic construction companies were collected and classified to organize the types of defects. Based on the classified data, eight types with a high incidence of window glass were analyzed according to the time of occurrence, and the cause and causal relationship of the defect were schematized. It aims to identify the degree of possibility of recurrence of defects for each of the eight defect types for experts and derive key management elements using the RII method. Therefore, the goal is to select key management elements of window construction that actively reflect the characteristics of the construction stage.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.629-635
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• 2011

Retentions are generally considered to be intended to act as a powerful tool to incentivize contractors/subcontractors to remedy defective work in cases of non-performance. This study attempts to establish the extent to which retentions can be used for this purpose by investigating case law connected with insurance and defective work. One of the significant questions is whether retentions are sufficient to deal with construction defects or value of retentions in the rectification of defects is illusory. The cost to repair a defect may vary depending on a number of components including type, cause, magnitude and the construction stage at which the defect occurs. It is expected that a review of existing cases on defective workmanship will provide an insight on the issues and whether retentions are effective in their intended function. In order to establish their functionality, the study described in this paper investigated 6 construction insurance cases to identify the critical issues and the causes of dispute. It was found that the nature and the cause of defects were different in each case. It was also established that certain defect types not covered by insurance may be covered by retentions - potentially one of the key uses of a retention strategy. It is expected that the findings will assist in forming a view on the quantum of money that may be required paving the way for a first time understanding on a rational basis for setting up retention regime.

• Journal of People, Plants, and Environment
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• v.23 no.3
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• pp.347-362
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• 2020

Background and objective: It is difficult to conclusively determine the exact cause of tree defects since multiple causes are involved such as climate change, plantation, tree quality and planting time, construction, planting base, drainage, sunshine conditions, maintenance, and microclimate. The data related to landscaping construction defects are scattered or fragmented by companies and years, but not managed systematically by the defect information management system. Most of the earlier studies associated with tree defects in apartment complexes suggested defect rates after examining tree defects in the completed construction site and proposed fragmentary and subjective conclusions about the causes of defects observed in trees with high defect rates. It is proposed to continue to conduct studies on the establishment and analysis of systematic databases to identify the exact causes of tree defects and measures to improve, and the need to accumulate systematic data in the construction process where many defects arises. This study was conducted to reduce the defects of trees planted in apartment complexes. Methods: Main factors related to tree defects were subdivided based on the results of literature review and a defect investigation at the completion site, and tree history management items were selected and subdivided during the construction stage. Results: The criteria for the preparation of subdivided items were obtained, and the tree history management checklist was written for the site under actual construction and a systematic database was established. Items that are categorized based to the causes of defects include the location of nurseries, date, tree quality, site conditions, planting techniques, microclimates, and maintenance. Conclusion: This study suggested tree history management items based on the tree defects that can be identified at the construction stage and applied them to the selected study site, which differentiates this study from earlier studies. It will be necessary to conduct a comprehensive and objective time series analysis on tree defects that occur over time by continuously monitoring and collecting data after construction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.223-224
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• 2022

The occurrence of defect, one of the major risk elements, gives rise to construction delays and additional costs. Although construction companies generally prefer to use a method of identifying and classifying the causes of defects, a system for predicting the rise of defects becomes important matter to reduce this harmful issue. However, the currently used methods are kinds of reactive systems that are focused on the defects which occurred already, and there are few studies on the occurrence of defects with prediction systems. This paper is about preliminary study on the development of judgemental algorithm that informs us whether additional works related to defect issue are needed or not. Among machine learning techniques, deep neural network was utilized as prediction model which is a major component of algorithm. It is the most suitable model to be applied to the algorithm when there are 8 hidden layers and the average number of nodes in each hidden layer is 70. Ultimately, the algorithm can identify and defects that may arise in later and contribute to minimize defect frequency.