• KIEAE Journal
• /
• v.14 no.5
• /
• pp.103-109
• /
• 2014

Apartment housing should require the systematic maintenance to provide the decent living condition during its life. Each household should participate the maintenance activities and pay for the repair. Therefore, the required cost for repair would be needed to plan in the repair schedule because each household could not pay the much repair money at a time. After apartment constructed, a long term repair plan would be prepared in repair time, repair scope and a required cost. A few studies are said that the repair cost depends on the building deterioration, elapsed year and management factors. The above factors are not be certain to affect the repair management while it may be important to prepare the required money and the repair time. In this paper, it aimed at analyzing the correlation between the repair management and the management factors, especially total area, number of household. This would educe the unit cost per number of household and management area in the individual boiler and elevator with full change and full repair. The unit cost per number of household and area for full change are about 199,000 won/household and $1,954won/m^2$ in the individual boiler respectively. The unit cost of the elevator for full change is 94,000 won/household and $5,429won/m^2$ respectively. Second, this study shows that the elapsed year after construction would not be related the repair unit cost.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.10
• /
• pp.248-258
• /
• 2020

This study proposed a breakdown structure for maintenance and management technologies under the concept of comprehensive asset management at the life cycle level of infrastructure based on benchmarking with other developed countries. For this purpose, a comparative case study was performed to review and analyze the existing definitions and hierarchies for infrastructure maintenance, repair, and rehabilitation (MR&R) systems under major industrialized countries and South Korea. In accordance with the ratio of maintenance costs to GDP, the U.S., U.K, and Japan were selected to review their systems. The classifications and definitions of MR&R technologies under the laws were analyzed. The result showed that most developed countries differentiate maintenance and repair from improvement and constitute a system centered on preventive maintenance activities. On the other hand, Korea's system for facility management is not definitely classified and still focused on reactive structures, which need to be improved. In this study, as proposed, a breakdown structure established the concept of Maintenance and Management, Maintenance & Repair, and Performance Improvement. Consequently, this study could be used as the basis for the implementation of preventive MR&R activities and reasonable resource allocations from an asset management point of view.

• International Journal of Reliability and Applications
• /
• v.1 no.1
• /
• pp.15-26
• /
• 2000

This paper considers an aperiodic preventive maintenance (PM) model for repairable systems, in which the time intervals between two consecutive preventive maintenances are unequal. To propose such an aperiodic PM model, we assume that each PM reduces the current hazard rate by a certain amount which depends on the number of PMs performed previously. If the system fails between PMs, the minimal repair is performed and the hazard rate remains unchanged after the repair. We give the exact expressions for the hazard rate function for the aperiodic PM model. Based on the proposed aperiodic PM model, we suggest the maximum likelihood method to estimate the parameters characterizing the model and apply the method to the case of Weibull distribution. Numerical examples for estimating the parameters are presented for the purpose of illustration.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.11a
• /
• pp.114-115
• /
• 2013

The maintenance and repair period consists the largest part of a construction project life cycle cost. However, it has been analyzed that the repairing plan relies on regulations and the officers' experience mostly that sometimes lead to performing unnecessary work. Moreover, the data occurred during repairing have not been stored in a system that can be used in future plans. Therefore, the purpose of this study is to suggest a repairing cost and time predicting model by applying the properties of the building.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.2
• /
• pp.10-19
• /
• 2019

Management plan with repairing is essential for RC structures exposed to chloride attack since durability problems occur with extended service life. Conventionally deterministic method is adopted for evaluation of service life and repair cost, however more reasonable repair cost can be obtained through continuous repair cost from probabilistic maintenance technique. Unlike the previous researches considering only normal distribution of life time, PLTFs (Probabilistic Life Time Function) which can be capable of handling log and normal distributions are attempted for initial and repair service life, and repair cost is evaluated for OPC and GGBFS concrete. PLTF with log distributions in initial service life is more effective to save repair cost since it is more dominant after average than normal distribution. Repair cost in GGBFS concrete decreases to 30% of OPC concrete due to longer initial service life and lower repairing event. The proposed PLTF from the work can handle not only normal distributions but also log distributions for initial and repair service life, so that it can provide more reasonable repair cost evaluation.

• Land and Housing Review
• /
• v.5 no.4
• /
• pp.297-303
• /
• 2014

Recently, block and permeable pavements have been placed in apartment complex. However. it is hard to decide the cycle of maintenance and repair due to lack of performance evaluation criteria for these pavements. This study carried out life cycle cost analysis(LCCA) to present resonable alternatives of the pavements by considering initial construction cost, maintenance and repair cost along with the cycle of repair. According to results of LCCA, the interlocking concrete block pavement is the best alternative when the repair cycle of 20years is assumed, while asphalt concrete pavement is the best alterative when the repair cycle of 10years is assumed. Therefore, the repair cycle is most important factor to select alternative. Also, it is necessary to develop resonable performance evaluation index to quantify the cycle of maintenance and repair in the future.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.3
• /
• pp.153-159
• /
• 2018

Many researches have been carried out on carbonation, a representative deterioration in underground structure. The carbonation of RC (Reinforced Concrete) structure can cause steel corrosion through pH drop in concrete pore water. However extension of service life in RC structures can be obtained through simple surface protection. Unlike the conventional deterministic maintenance technique, probabilistic technique can consider a variation of service life but it deals with only normal distributions. In the work, life time-probability distributions considering not only normal but also log distributions are induced, and repair cost estimation technique is proposed based on the induced model. The proposed technique can evaluate the repair cost through probabilistic manner regardless of normal or log distribution from initial service life and extended service life with repair. When the extended service life through repair has log distribution, repair cost is effectively reduced. The more reasonable maintenance strategy can be set up though actual determination of life-probability distribution based on long term tests and field investigations.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.11 no.4
• /
• pp.458-466
• /
• 2023

Structures in our surroundings deteriorate over time due to environmental and chemical factors, resulting in a decrease in their performance. The primary causes of degradation in concrete structures are carbonation, salt damage, and freeze-thaw cycles. Various maintenance methods exist to address these degradation issues. However, research and technological development for existing maintenance methods have been ongoing, but the accuracy and effectiveness of repair materials and techniques have not been extensively validated. Therefore, in this study, we conducted a material performance evaluation of various manufacturers' repair materials. Based on this evaluation, we applied corrosion inhibitors and epoxy, which are the methods most closely related to crack repair, to assess the durability performance against carbonation, salt damage, and freeze-thaw cycles. The results show approximately a two-fold performance improvement against carbonation and salt damage, and a 5% enhancement in repair performance against freeze-thaw cycles. Thus, it is considered effective in preventing rebar corrosion when appropriate maintenance is carried out according to environmental and chemical factors during structural repairs.

• Communications for Statistical Applications and Methods
• /
• v.6 no.1
• /
• pp.99-106
• /
• 1999

This paper considers an imperfect repair model for which the repairable system is maintained preventively at periodic times and is replaced by a new system when a predetermined number of preventive maintenance has been applied. our main objective of this is to determine the optimal number of preventive maintenances before the system is replaced and the optimal length of interval between two consecutive preventive maintenances under a new repair model which is referred to as an ineffective preventive maintenance. Such a model assumes a periodic preventive maintenance in which the system is effectively maintained with a certain probability. Otherwise the system is not improved at all after each maintenance and thus the failure rate remains the same as before. The criteria to determine the optimal number of preventive maintenances and length of period is the expected cost rate per unit time for an infinite time span. We give the explicit expressions for the expected cost rate per unit time. Some numerical examples are presented for illustrative purposes.

• Korean Journal of Construction Engineering and Management
• /
• v.23 no.3
• /
• pp.83-94
• /
• 2022

The number of public rental housing has increased according to the government's 「Housing Welfare Roadmap (2017)」, and facility maintenance costs for the demand of improvement of performance and residential standards due to the aging of long-term public housing are significantly increasing. Consequently, the financial burden of public housing rental business for maintaining stocked housing is aggravated. However, there is a lack of objective data to analyze the size of the maintenance costs that are executed by the type of repair work, and the elapsed years of the aged long-term public rental housing. This study analyzes the execution status of 33 long-term public rental housing complexes located in Seoul for 14 to 28 years of elapsed years based on the data of maintenance costs. In addition, this study proposes a model to predict the maintenance costs by elapsed years by dividing 'Long-term Repair Plan Work and Government-Funded Project [Y₁]', 'Planned Repair Work and General & Unplanned Repair Work [Y₂]', and 'Total maintenance costs [Y₃]'. It is intended to be used as basic data for the establishment of the maintenance plan at the stage of setting up the budget and the establishment of the sustainable operation plan for public rental housing