Showing papers in "Journal of the Korean Institute of Building Construction in 2015"
TL;DR: A drawing segmentation algorithm is suggested for managing building finish details individually and a system module for making detail blocks from files of finish details is developed, to reduce of the time for searching and increases productivity of designed drawings.
Abstract: Drawings in construction industry are an aggregation of knowledge containing various information generated in a number of projects. Finish details are generated by architects when they select details and methods of construction by spaces or elements. However it is so difficult to re-use details in existing drawing management systems because there are so many details in a sheet and there are several many kinds of sheets in a file. In this paper, a drawing segmentation algorithm is suggested for managing building finish details individually. Based on this algorithm, a system module for making detail blocks from files of finish details is developed. Using the drawing segmentation module, interfaces of drawing management system are suggested in the paper. Management of individual detail blocks helps to reduce of the time for searching and increases productivity of designed drawings. Also it would contribute to increase quality of designed drawings by reusing of knowledge in detail blocks.
9 citations
TL;DR: In this paper, the authors analyzed the noise characteristics about noise type, sound level, and noise occurrence frequency of living noise in residential buildings and proposed a management plan based on the actual state of the noise occurrence, considering the individual noise source and the time slot during noise frequently occurs.
Abstract: The purpose of this study is to analysis the noise characteristics about noise type, sound level, and noise occurrence frequency of living noise in residential buildings. The field measurement was conducted to classify the types of living noise and to examine the actual states of noise occurrence for each living noise source. Among the 24 types of living noise, 10 noise sources were selected based on the loudness and frequency of each living noise. The result indicated that 10 noise sources show the difference on each noise occurrence characteristic by time zones. Therefore, to reduce noise, a management plan should be introduced based on the actual state of the noise occurrence, considering the individual noise source and the time slot during noise frequently occurs. Moreover, the noise standard for each noise types of living noise should be specificated and the education for residents about characteristics of living noise types should be conducted to improve the consciousness of residents.
9 citations
TL;DR: In this article, the authors present a method to find the optimal solution to the problem of how to improve the performance of the user. But they do not specify a method for the user to select the best solution.
Abstract: 본 연구에서는 저온환경에 고분말도 시멘트를 적용하기 위하여 기초 특성을 검토하고자 하였다. 실험 결과 일반 시멘트에서 입도 분급된 고분말도 시멘트는 초기 수화에 큰 영향을 미치는 10㎛이하의 입자가 다수 분포하였으며 분말도가 매우 높은 것으로 나타났다. 또한 분급된 미세한 시멘트 입자는 초기 수화반응이 매우 빠르고 이것은 시멘트의 수화 반응을 상승시킨다. 또한 고분말도 시멘트는 응결시간이 단축되고 모든 재령에서 압축강도가 높게 나타났다. 특히 저온환경에서는 초기 3일 압축강도 발현속도가 OPC 보다 2배 이상 발현하는 것을 확인할 수 있었으며 미소수화열 분석을 통해 수화반응 속도가 빠르고 수화열 또한 높은 것을 확인하였다. 또한 단열온도 상승 실험을 통해 초기 수화발열상승온도 및 최고 상승온도가 높은 것으로 나타났다. 따라서 본 연구범위 내에서 저온환경 콘크리트에 우수한 시멘트 원료는 고분말시멘트로 판단된다.
4 citations
TL;DR: In this paper, the authors investigated defect status by work type, based on the report data of defect inspection results, acquired by consumers' request to safety inspection agencies, before the expiration of legal defect repair warranty period.
Abstract: This study investigated defect status by work type, based on the report data of defect inspection results, acquired by consumers’ request to safety inspection agencies, before the expiration of legal defect repair warranty period. In fact, the data was not acquired by centering on suppliers, namely, construction companies in relation with the defects becoming causes to increase construction cost of apartments. This study aims to provide objective and basic data for quality improvement at construction stage and for solution to defect disputes. The study results are presented below: (1) The number of defect cases occurring from architectural work among total work types were 1,986, defect occurrence rate was 62.5%, and defect repair cost was KRW 25,851/㎡, which stood at 78.2% of the total work types. This means the defect occurrence rate and defect repair cost in architectural work are bigger than those of other work types. (2) Major defects in architectural work were revealed in the following order: cracks from frame work, inferior interior finishing work, inferior finishing work of plaster/masonry works, water leak/damage from waterproof work and withering/omission from landscape work. The total repair cost of the major selected defects was KRW 12,220/㎡, and was analyzed to take up 37% of the total defect repair cost.
4 citations
TL;DR: In this paper, the quality characteristics test of the recycled aggregates by applying the four kinds of surface treatment using a colloidal suspension of approximately 5nm∼60nm particle size with the alkalinity of pH 10.2.
Abstract: The research, in order to enhance the quality of recycled aggregate, was carried out the quality characteristics test of the recycled aggregates by applying the four kinds of surface treatment using a colloidal suspension of approximately 5nm∼60nm particle size with the alkalinity of pH 10.2. The quality tests of recycled aggregate have been processed by specific gravity, water absorption, porosity, surface properties, and the compression and tensile tests. The colloidal suspension was coated effectively the surface of the old cement mortars of recycled aggregate with a constant thickness by colloidal suspension is being applied to the recycled aggregate surface under constant pressure of 100kpa and then it was dried in at 60°C. The surface treatment method by the Method C out of 4 kinds of surface treatment improved effectively the quality of the recycled aggregates, whereby it obtained the best compressive strength and tensile strength of the recycled aggregate concrete.
3 citations
TL;DR: In this article, a survey was conducted targeting on safety managers, in which the managers evaluated lifelikeness, active learning and enjoyment that each of the training methods can promote.
Abstract: Construction worker safety and safety training continue to be main issues in the construction industry. In order to promote safety awareness among workers, it is imperative to develop a more effective and efficient safety training. This study compared two methods in construction worker safety training: 1) a conventional lecture and 2) 3D simulation through Building Information Modeling. Both training methods included the same contents, a selection of safety standard and guide suggested by Occupational Safety and Health Agency and the Korea Occupational Safety and Health Agency; the contents were then produced into two types of training methods. A survey was conducted targeting on safety managers, in which the managers evaluated lifelikeness, active learning and enjoyment that each of training methods can promote. The results of the survey showed that innovative method using 3D simulation was more effective than conventional lecture method in terms of its lifelikeness, active learning and enjoyment. This study will provide implications that innovative method using the virtual reality is more effective than conventional lecture method.
3 citations
3 citations
TL;DR: In this article, the cost and workload of single-layer placement of formwork for the Reactor Containment Building (RCB) exterior wall through lateral pressure according to the height of concrete placement, the deformation criteria for formwork, and a new form design, ''MIDAS GEN (hereinafter referred to as MIDAS)` is used in this study.
Abstract: Technologies for reducing construction duration are key factors in nuclear power plant construction projects, as a reduction in construction duration at the construction phase leads to a reduction in construction cost and an increase in profits through the early operation of the nuclear power plant. To analyze the constructability of the height of single-layer placement of formwork for the Reactor Containment Building (RCB) exterior wall through lateral pressure according to the height of concrete placement, the deformation criteria for formwork, and a new form design, `MIDAS GEN (hereinafter referred to as MIDAS)` is used in this study. The cost and workload of formwork are derived according to the unit of height of the RCB exterior wall. Based on the result, it was found that the higher the RCB exterior wall, the higher the material cost, and the less the construction duration and the less the total number of formwork layers. Based on this result, it is believed that the material cost and the construction duration can be appropriately determined according to the formwork height.
3 citations
3 citations
TL;DR: In this paper, the authors reveal the influence of the field organizational culture on the performance of building construction projects and show that best performed projects have higher characteristics of a consensus culture and rational culture, and worst performed projects had the lower characteristic of a development culture and consensus culture.
Abstract: Construction companies want to improve the abilities of field organizations for improving the performance of construction projects. It is possible to improve the performance of construction projects by managing the field organizational culture, due to the field organizational culture is concerned with the abilities of construction field organizations. Therefore, the purpose of this study is to reveal the influence of the field organizational culture on the performance of building construction projects. The results of this study showed that field organizational cultural characteristics influence on the performance of construction projects. Best performed projects have the higher characteristics of a consensus culture and rational culture, and worst performed projects have the lower characteristics of a development culture and consensus culture. In addition, the characteristics of rational culture and hierarchy culture effect on the performance in worst performed projects. This study is expected to help to improve the performance management system in construction field organization.
3 citations
TL;DR: In this paper, the authors proposed a method to solve the problem of how to improve the quality of the service provided by the service provider by using the information of the user's behavior.
Abstract: 1978년에 고리 1호기의 건설이 완공된 이래로 원자력발전 플랜트의 건설 프로젝트는 국내·외로 점차 확대되고 있다. 그러나 일부 원자력 발전 플랜트의 건설 현장에서는 리스크 관리 능력의 부족으로 인하여 공기 지연과 공사비손실의 문제점들을 가지고 있다. 특히, 원자력 발전 플랜트내 원자로격납건물의 시공은 타 시공 단계에 비해 긴 공정기간으로 인하여 전문기술과 대규모 자원이 요구됨에 따라 많은 리스크 요인들이 산재될 수 있다. 따라서 원자로격납건물의 시공에서 예상되는 리스크 요인들을 분석하여 전체프로젝트의 안정적인 수행 방향을 제시하는 연구가 필요하다. 그러므로 본 연구는 원자로격납건물 시공의 리스크 요인들을 평가하고자 한다. 이를 위하여 본 연구는 36명의소수 전문가 집단을 대상으로 하는 설문조사방법을 활용하였다. 24개의 리스크 요인들은 공정, 원가, 안전, 품질을기준으로 분류되었으며, 이에 대한 평가 결과는 계층 분석방법을 활용하여 분석하였다. 이를 바탕으로 각 기준별로분류된 리스크 요인들은 중요도와 우선순위를 산정하고 원자력 발전 플랜트의 시공 리스크 요인을 분석하는데 계층분석 방법의 적용성을 확인하였다. 본 연구의 결과는 원자로격납건물의 시공 단계에서 리스크 관리를 위한 기초 자료로 활용될 수 있을 것이다.
TL;DR: In this paper, the effect of BIM applied in the construction site is analyzed empirically throughout the survey at a construction site in accordance with the training, evaluation, and implementation of the BIM.
Abstract: As recent buildings have been enlarged and free-formed, it is hard to represent three-dimensional buildings with two-dimensional drawings and identify design errors, construction errors, difference of construction quantity and construction cost, clash with columns, beams, pipe machinery, and so on. In order to overcome the limitations, BIM(Building Information Modeling) has been used in construction industry. However, BIM in the construction site is not fully facilitated after practical implementation in process control including training, evaluation and analysis of the process. Therefore, in this study, the effect of BIM applied in the construction site is analyzed empirically throughout the survey at the construction site in accordance with the training, evaluation, and implementation of BIM.
TL;DR: In this article, the key technology of Energy Saving Environmental-Friendly Building is sorted into 3rd categories, and the analysis of patent trend for patent documents published in Korea, USA, Japan and Europe is carried out.
Abstract: The building structure has an decisive influence on the environment as it takes over one third part in the energy consumption and greenhouse gas emissions of whole world. Accordingly, every country makes the reduction of greenhouse gas emission compulsory pursuant to Kyoto Protocol of 1997, and Korea government makes an announcement for the improvement of building energy performance in 2014. In this study, the key technology of Energy Saving Environmental-Friendly Building is sorted into 3rd categories, and the analysis of patent trend for patent documents published in Korea, USA, Japan and Europe is carried out. The purpose of this study is to solve the problem of current technology that it cannot show the detailed situation of technique and development strategy of R&D, and to provide a systematic approach for R&D strategy and an exact technology development direction.
TL;DR: In this article, the authors suggest application method of the wasted rock obtained from the limestone quarry of raw material for cement as a coarse aggregate for high strength concrete after crushing and sieving processes.
Abstract: The aim of this research is suggesting application method of the wasted rock obtained from the limestone quarry of raw material for cement as a coarse aggregate for high strength concrete after crushing and sieving processes. The wasted rock has been normally wasted because of its low quality as a material for cement production. In this research, the concrete using this wasted limestone coarse aggregate was evaluated the constructability based on the performances of workability, air content, and compressive strength. From the experiment, a favorable performance was achieved with a limestone coarse aggregate for high strength concrete comparing to the high strength concrete using granite coarse aggregate.
TL;DR: In this article, a mixture proportioning approach of crack controlled lightweight foamed concrete without using high-pressure steam curing processes, as an alternative to autoclaved lightweight concrete blocks was developed.
Abstract: The objective of this study is to develop mixture proportioning approach of crack controlled lightweight foamed concrete without using high-pressure steam curing processes, as an alternative to autoclaved lightweight concrete blocks (class 0.6 specified in KS). To control thermal cracks owing to hydration heat of cementitious materials, 30% ground granulated blast-furnace slag (GGBS) was used as a partial replacement of ordinary portland cement (OPC). Furthermore, polyvinyl alcohol (PVA) and polyamid (PA) fibers were added to improve the crack resistance of foamed concrete. The use of 30% GGBS reduced the peak value of hydration production rate measured from isothermal tests by 28% and the peak temperature of foamed concrete measured from semi-adiabatic hydration tests by 9%. Considering the compressive strength development, internal void structure, and flexural strength of the lightweight foamed concrete, the optimum addition amount of PVA or PA fibers could be recommended to be , although PA fiber slightly preferred to PVA fiber in enhancing the flexural strength of foamed concrete.
TL;DR: In this paper, the engineering properties of HPFRCC with combined long steel fiber (SL) and long organic fiber (OL) are evaluated such as workability and strength, the most favorable performance was obtained when the mixture contained 1.5% of combined SL and OL.
Abstract: The high performance fiber reinforced cementitious composite (HPFRCC) controls the cracking development of the structure by inducing micro-cracking and strain hardening behavior after the initial cracking under the tensile conditions. Although, in Korea, the research about manufacturing the single-fiber reinforced cementitious composite or the mechanical properties of hardened status has been conducted, the research to apply the HPFRCC with multi-fiber is not sufficient. Hence, in this research, considering the workability and economic aspect for practical applications, the engineering properties of HPFRCC with combined long steel fiber (SL) and long organic fiber (OL) are evaluated such as workability and strength. As a result of evaluating the engineering properties of HPFRCC, the most favorable performance was obtained when the mixture contained 1.5% of combined SL and OL.
TL;DR: In this article, the authors propose a VAE for VAE-based VAE, where the VAE is composed of two groups: VAE 1 and VAE 2.
Abstract: 현재 건축분야에서는 시멘트 혼화용 폴리머를 혼입한연구가 진행되고 있는 상황이다. 하지만 대부분의 연구는 보통강도 배합을 대상으로 연구가 진행되고 있다. 따라서 본 연구에서는 고강도 배합과 보통강도 배합에 VAE 계열의 분말형 폴리머를 혼입하여 고강도 폴리머 시멘트 모르타르의 강도 특성 및 역학적 성질을 검토하고자 하였다. 실험결과, 고강도 배합의 경우 VAE 폴리머 적용 시 폴리머 혼입양이 증가할수록 보통강도 배합에 비해 압축강도 및 휨강도가 감소하는 단점을 나타내지만, 폴리머필름 형성으로 인하여 인장강도 및 부착강도가 향상되는 장점을 나타내었다.
TL;DR: For instance, the authors found that 60% of the respondents agreed with the following conclusions: 1.5% of respondents agreed that ALC should be used more often and 3% of those agreed that it should be less frequently used.
Abstract: 본 연구의 목적은 ALC 블록대체를 위한 고성능 기포콘크리트 배합설계를 개발하는 것이다. 대기양생 하에서 기포콘크리트의 고강도 발현(특히 초기재령에서)을 위하여 결합재 및 혼화제를 사전연구에서 다음과 같이 설계하였다. 규산3칼슘이 60% 이상인 보통포틀랜드시멘트에 무수석고 3%를 첨가하였으며, 폴리카르본산계 감수제에서 폴리알킬에테르 성분을 28%로 조절하였다. 이들 재료를 사용하여 물-결합재비와 단위결합재양을 변수로 기포콘크리트 11배합을 실험하였다. 배합된 기포콘크리트의 품질 및 실용성은 KS 규격의 ALC 블록의 요구조건 및 기존의 일반 기포콘크리트와 비교하였다. 실험결과 본 연구의 고성능 기포콘크리트는 ALC 블록의 요구조건을 만족하면서 높은 실용가능성을 보였다.
TL;DR: In this paper, the level of CO₂ absorption in mortar with various binders including cement and nonsintered cement was examined and the compressive strength was similar to the one without the bacteria at early age but decreased at the age of 28 days.
Abstract: In this research, the CO₂ absorption performance of mortar was investigated. The level of CO₂ absorption in mortar with various binders including cement and nonsintered cement was examined. As a result for the mortar with photosynthetic bacteria, the compressive strength was similar to the one without the bacteria at early age but decreased at the age of 28 days. However, for the CO₂ absorption, with photosynthetic, the performance of the mortar with OPC, and nonsintered cement deceased to 21%(234 ppm) and 19.7%(243 ppm) respectively after 12 hours age.
TL;DR: In this article, the thermal conductivity, physical and mechanical properties of lightweight aggregate concretes with hollow micro sphere(HMS) are experimentally examined as a basic research for the development of structural insulation concrete.
Abstract: In this study, the thermal conductivity, physical and mechanical properties of lightweight aggregate concretes with hollow micro sphere(HMS) are experimentally examined as a basic research for the development of structural insulation concrete. As the results of this experiment, in the case of concrete mixed with HMS, the value of slump has been reduced, so it is found that the dosage of superplasticizer should be increased. As the replacement ratio of HMS increases, it has shown that the compressive strength is somewhat decreased due to the low interfacial adhesion strength of HMS. But the thermal conductivity is found to be greatly improved with the replacement ratio of HMS increases, the thermal conductivity of HMS shows the lower value of 68% at lightweight aggregate concrete and 32% of normal concrete. Also it is found that the compressive strength is decreased and thermal conductivity is increased as the water-cement ratio increases. The most outstanding for insulation performance is observed when using 20% of HMS and 50% of water-cement ratio.
TL;DR: In this article, the authors present a mock-up of a game where the players are divided into two groups: the audience and the game player, each of which is composed of two players.
Abstract: 도심지 건물의 증가는 친환경 공간에 대한 요구를 발생시키고, 이에 따라 옥상 및 인공지반 녹화의 보급이 급속히 증가되고 있다. 녹화시공은 방수층, 방근층, 보호콘크리트등과 같이 다양한 재료를 시공하므로 시공시간이 길고, 하자 발생가능성이 높아진다. 본 연구는 기존의 녹화시스템 시공단계를 단축, 시공성을 향상시킨 새로운 녹화시스템에 사용하는 일체화된 방수·방근 하이브리드 시트의 물리적성능, 내구성, 방수성, 방근성을 평가함으로써 성능수준을 확인하고, 현장 적용 여부를 판단하고자 하였다. 시험결과, 우수한 물리적 성능 및 내구성, 방수성, 방근성을 확인하였으며, 향후 mock-up 시험을 수행하여 장기성능을 검증 중이다.
TL;DR: In this article, the authors evaluated the initial crack index by FEM analysis to find the crack propagation from hydration heat in precast concrete, and demonstrated that the hardening accelerators accelerated the hydration reaction of cement, and caused the increase of hydration temperature within a short period of time.
Abstract: In this study, initial crack index was evaluated by FEM analysis to find the crack propagation from hydration heat in precast concrete. As results, as the usage of hardening accelerator increased, initial compressive strength increased and setting time was shortened. Additionally, as amounts of hardening accelerators increased, the central temperature of concrete increased and the time to reach the highest temperature was shortened. It was demonstrated that the hardening accelerators accelerated the hydration reaction of cement, and caused the increase of hydration heat within the short period of time. Furthermore, the crack index for evaluating the heat level was performed by FEM. As results, there was no problem about the cracks, despite of the growth of initial high hydration heat. This is because of the increased tensile strength that is large enough to sustain the thermally induced-stress.
TL;DR: In this article, the performance of non-cement mortar with fly ash from combined heat power plant and recycled fine aggregate according to replacement ratio of fine aggregate based on the optimum mix from the basic experiment was evaluated.
Abstract: In this study, to suggest the application method of recycled fine aggregate, the non-cement mortar was prepared and studied with the binders of blast furnace slag, fly ash, and fly ash from combined heat power plant. As a basic experiment, a series of tests was conducted to determine the potions of the binders and types of activator. When the binder was consisted with 20% of fly ash and 40% of fly ash from combined heat power plant, the highest strength of the mortar was obtained, and as an activator, the combination of sodium hydroxide 2.5%, and calcium hydroxide 7.5% showed the highest strength of the mortar. Therefore, this study focuses on engineering properties of mortar contains fly ash from combined heat power plant and recycled fine aggregate according to replacement ratio of recycled fine aggregate based on the optimum mix from the basic experiment. As a result, the best replacement ratio of recycled fine aggregate is 75%.
TL;DR: In this paper, an airborne chloride simulator was set up, in order to conduct a corrosion accelerating test for steels coated by five different finishing materials, and it was found that the corrosion began to be observed at 0.58～0.73㎎/dm² for no-coated steel, at 7.89ﾞ8.46ﾾ 8.35ﾽ
Abstract: Many studies have investigated the airborne chlorides that can weaken the overall durability of the concrete structures due to the corrosion of steel materials, but most of the studies have aimed to examine weathering by exposing various construction materials to the actual oceanic environment. However, with the exposure test, it was difficult to find the threshold of precise corrosive amount of airborne chlorides due to diverse deteriorating environmental factors such as ultraviolet ray, acid rain, floating material from industrial pollution as well as airborne chlorides. Therefore, in this study, an airborne chloride simulator was set up, in oder to conduct a corrosion accelerating test for steels coated by five different finishing materials. As results, it was found that the corrosion began to be observed at 0.58～0.73㎎/dm² for no-coated steel, at 7.89～8.46㎎/dm² for urethane-coated steel, at 57.95～69.48㎎/dm² for red lead-coated steel, and at 80.73～89.35㎎/dm² for stainless-coated steel, respectively. Hence, these specific data can be considered as the threshold ranges of corrosion for each coating material for steel.
TL;DR: For instance, this article found that 60% of the respondents thought that Korean women are more likely to commit suicide than women in South Korea, while only 15% of men did.
Abstract: 공동주택의 에너지 의무 절감률이 현재 40%에서 2017년에는 60%까지 단계적으로 상향 조정되면서 에너지 절감을 위해 외단열 공법이 주목받고 있다. 그러나 기존 외단열 공법은 내단열 공법에 비해 추가되는 공사비와 공사기간으로 인해 활성화가 미흡한 실정이다. 따라서 본 연구는 외단열공사와 골조공사를 연속적으로 시공함으로서 공사기간을 단축하고 공사비를 절감할 수 있는 외단열 적층시공 공법의 개념모델을 개발하고 사례적용을 통해 공법의 타당성을 검증하였다. 연구결과 외단열 적층시공 공법은 기존의 외단열 공법에 비해 6.7%의 공기절감 효과와 13%의 외단열 공사비 절감효과가 있는 것으로 나타났다. 본 연구의 결과인 적층시공공법은 외단열 공법적용의 저해요소를 해결하여 향후 외단열 공법 활성화에 기여할 것으로 기대된다.
TL;DR: In this paper, the authors investigated and analyzed the on-site situation of the fenestration energy consumption efficiency rating system and the energy-saving design criteria for buildings, and they found that overall understanding of the FENESTRA ECA was high, satisfaction with it was low, and the general practice at construction sites was to use windows assembled on site rather than integrated window systems manufactured at factories, thus making it difficult to confirm that the current rating system was well applied on site.
Abstract: At present, in the case of small and medium window manufacturers in South Korea, glazing and window frame manufacturers are divided into separate businesses. However, in the fenestration energy consumption efficiency rating system and the energy-saving design criteria for buildings, the coefficient of overall heat transmission standard for windows is defined by window sets, which integrate glazing and window frames. At most construction sites, windows are constructed by installing separately supplied glass and frames. Research that can integrate the reality and the system is therefore necessary. The present study first investigated and analyzed the on-site situation of the fenestration energy consumption efficiency rating system. According to the results, while overall understanding of the fenestration energy consumption efficiency rating system was high, satisfaction with it was low, and the general practice at construction sites was to use windows assembled on site rather than integrated window systems manufactured at factories, thus making it difficult to confirm that the current rating system was well applied on site. Consequently, the reality of industrial sites must be reviewed and a realistic alternative to the fenestration energy consumption efficiency rating system must be presented instead of focusing on theory.