• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.165-166
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• 2010

In this study, it was accomplished to analyze the productivity and manpower through the activity of rebar work for the application of rational construction cost in apartment house. And the rebar work is very important in the view of the expense and safety, and durability in the construction of R/C structure. Also the rebar work is very affected with productivity owing to the lack of manpower and materials cost rise.

• Journal of the Korea Institute of Building Construction
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• v.23 no.3
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• pp.315-326
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• 2023

The design principles and implementation of rebar lap splice in architectural structures are governed by building regulations. Nevertheless, the minimization of rebar-cutting waste (RCW) is often impeded by the mandatory requirements pertaining to the rebar lapping zone as prescribed in design codes. In real-world construction scenarios, compliance with these rules often falls short due to hurdles concerning productivity, quality, safety, time, and cost. This discrepancy between code stipulations and on-the-ground construction practices necessitates an academic exploration. The goal of this research was to delve into the effect of rebar lap splice placement on the robustness and constructability of building edifices. The study initially took on a review of the computation of rebar lapping length and the rules revolving around the lapping zone. Following this, a structural robustness and constructability examination was undertaken, focusing on adherence to the lap splice zone. The interpretations and deductions of the research led to the following insights: (1) the efficacy of rebar lap splice is not solely contingent on the moment, and (2) the implementation of rebar lap splice beyond the specified zone can match the structural integrity and robustness of those confined within the designated area. As a result, the constraints on the rebar lapping zone ought to be revisited and possibly relaxed. The conclusions drawn from this research are anticipated to reconcile the disconnect between building codes and practical construction conditions, furnishing invaluable academic substantiation to further the endeavor of achieving near-zero RCW.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.13-22
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• 2020

Reinforcement steel fixing is a skilled and manually intensive construction trade. Current practice for the quality assessment of reinforcement steel fixing is normally performed by fabricators and has high potential in having errors due to the tedious nature of the work. In order to overcome the current inspection limitation, this study presents an approach that provides visual assistance and inspection enhancement for inspectors to assess the dimensional layout of reinforcement steel fixing. To this end, this study aims to establish an end-to-end framework for rebar layout quality inspection using laser scanning and Augmented Reality (AR). The proposed framework is composed of three parts: (1) the laser-scanned rebar data processing; (2) the rebar inspection procedure integrating with AR; and (3) the checking and fixing the rebar layout through AR visualization. In order to investigate the feasibility of the proposed framework, a case study assessing the rebar layout of a lab-scaled formwork containing two rebar layers is conducted. The results of the case studies demonstrate that the proposed approach using laser scanning and AR has the potential to produce an intuitive and accurate quality assessment for the rebar layout.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.485-496
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• 2023

Precise construction cost estimation is paramount to determining the total construction expense of a project prior to the initiation of the construction phase. Despite this, manual quantification and cost estimation methods, which continue to be widely used, may result in imprecise estimation and subsequent financial loss. Given the fast-paced and efficiency-demanding nature of the construction industry, trustworthy quantity and cost estimation is essential. To mitigate these obstacles, this research is focused on establishing an automated quantity estimation algorithm, particularly designed for the main rebar of beams which are recognized for their complicated reinforcement configurations. The exact quantity derived from the proposed algorithm is compared to the manually approximated quantity, reflecting a variance of 10.27%. As a result, significant errors and impending financial loss can be averted. The implementation of the findings from this research holds the potential to significantly assist construction firms in quickly and accurately estimating rebar quantities while adhering strictly to applicable specifications and regulatory requirements.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.89-90
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• 2023

This dissertation investigates the feasibility of accurately calculating the required rebar length using BIM-based shape codes and the potential benefits of such an approach in terms of cost reduction, waste reduction, and environmental improvement. The study aims to explore the possibility of automatically calculating slab rebar length before construction to reduce rebar cutting waste and cost. The results of this study will provide insights into the potential of using shape codes to reduce rebar cutting waste and cost in building frame construction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.243-246
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• 2009

Importance of quality control is gradually increasing in the construction. And the reber work is very important things which influence in safety and durability of the building and accounts for about 9.8% of the total cost. Although reber work is important, quality control of the rebar work is still performed by attitude and experience of worker. Therefore, it is very important to quality achievement effort and quality standards recognition of rebar worker for quality sophistication in the construction. Some papers have dealt with the quality control in construction. But there was no study for actual conditions of quality standards recognition of rebar workers. The purpose of this study is to survey the actual conditions of quality standards recognition of rebar workers and to analyze difference of consciousness of administrator and worker. The result are : there id difference of consciousness of worker and administrator, workers work without knowing quality standard.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.15-16
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• 2013

Because of the complicated shape and the overcrowded arrangement of rebar, there are some problems in applying the rebar modulation for the Nuclear Power Plant Structures. In order to resolve these problems, we have been studying the rebar modulation method applying techniques of the high strength rebar for NPP Structure. After reviewing the rebar drawing of the NPP structures and performing the mock-up test, the rebar modulation method in the various area of the NPP Structure has been established. I will introduce this method and the future plan of the research.

• Korean Journal of Construction Engineering and Management
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• v.10 no.6
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• pp.58-66
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• 2009

Due to a shortage of professional labor and the stagnant construction industry in recent days, there has been an increasing demand for securing profitability through cost reduction. Though its importance in the cost and its great influence on the safety and durability of structures, the labor intensiveness of rebar work has caused a serious problem of rising cost accompanied by the loss of rebar materials. In the plant manufacturing process, rebar is cut and bent at the automated facilities and conveyed to the construction site, which makes it possible to manufacture higher-quality bars and to reduce the losses from rebar materials. Different from the expectation, however, this type of plant manufacturing still has not been active since its first introduction in 1990s. In this study, a research on the actual condition of rebar manufacturing plant has been implemented and a standardized rebar manufacturing has been provided as a way to activate rebar manufacturing.

• Korean Journal of Construction Engineering and Management
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• v.25 no.2
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• pp.69-80
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• 2024

Currently rebar spacing inspection is carried out by human inspectors who heavily rely on their individual experience, lacking a guarantee of objectivity and accuracy in the inspection process. In addition, if incorrectly placed rebars are identified, the inspector need to correct them. Recently, laser scanning and AR technologies have been widely used because of their merits of measurement accuracy and visualization. This study proposes a technology for rebar spacing inspection and fixing by combining laser scanning and AR technology. First, scan data acquisition of rebar layers is performed and the raw scan data is processed. Second, AR-based visualization and fixing are performed by comparing the design model with the model generated from the scan data. To verify the developed technique, performance comparison test is conducted by comparing with existing drawing-based method in terms of inspection time, error detection rate, cognitive load, and situational awareness ability. It is found from the result of the experiment that the AR-based rebar inspection and fixing technology is faster than the drawing-based method, but there was no significant difference between the two groups in error identification rate, cognitive load, and situational awareness ability. Based on the experimental results, the proposed AR-based rebar spacing inspection and fixing technology is expected to be highly useful throughout the construction industry.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.531-542
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• 2022

As buildings become taller, the strength of structural materials must increase and the amount of rebar reinforcement also increases while the application of an appropriate rebar splice method in the construction process become one of the essential factors. In this research, the current status of quality check for rebar coupler is identified by an expert questionnaire and an appropriate quality check method is proposed through a quality test on specimens similar to actual on-site construction. In the test results, it was revealed that, among the quality check methods for rebar coupler joints, the coupler tightening method and face to face degree of between upper and lower rebar did not affect the strength the specimen. Therefore, it is considered to be an appropriate way to check the coupler quality check to check whether the threads are completely assembled during on-site construction through manufacture the number of threads of rebar and coupler with a margin beyond the calculated thread number.