Proceedings of the Korean Institute of Building Construction Conference (한국건축시공학회:학술대회논문집)
The Korean Institute of Building Construction
- Semi Annual
Domain
- Construction/Transportation > Construction Engineering/Materials/Management
2013.11a
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In recent downtown high land due to an increase in the utilization of land from the property line to maximize the proximity of the construction and use of underground structures has increased. The nature of urban underground retaining structure construction safety, environmental management, and civil contrast situations, construction periodt perspective, this method is widely used in the backhand. Recent Patents DP method and the method of the DBS method than in the SPS process is deleted according to the PRD process cost savings are generated. The workability and safety study of two kinds of method, such as air speed, and considering the reduction of indirect costs in terms of economic efficiency is considered to be a superior method.
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Inorganic binding material was made by recycled resource and its applicability as pile-filling material was examined. The result was that the material had same liquidity with the liquidity of OPC and high reactivity with site soil. According to dynamic/static loading tests by site test-construction, the inorganic binding material met both design bearing capacity and settlement. Since the inorganic binding material showed same or better performance than OPC, the utilization possibility of the inorganic binding material made of recycled resource as pile-filling material was verified.
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It is required to response to the demand for new space due to high density of population and buildings in urban area. In particular, in case of big cities such as Seoul where the lack of new construction site due to the depletion of available space, existing buildings must be demolished for new construction. Utilization of urban underground space can be an alternative to solve for urban space problems. There are applications of underpinning methods using micropiles for existing buildings. Sometimes, the difficulties come from the compact space available for new foundation underneath the existing ones. In this paper, a novel underpinning method is introduced which can solve the space restriction problems underneath existing columns.
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Mechanical splices has been applied in nuclear power plant according to ASME(American Society of Mechanical Engineering) and ACI(American Concrete Institute) Code requirements. In particular sleeve with ferrous filler metal splices and cold roll formed parallel threaded splices have been used in domestic nuclear power plants. The objective of this study is to find out the constructability of the mechanical splices which had been used in Korea nuclear job site and to review the technical trends in the near future.
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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.
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To minimize construction of nuclear facility, it is required to reduce reinforcing bar amount and solve reinforcing bar concentration and for this, it is necessary to develop appication design technology and modular of high strength reinforcing bar. Hence, KHNP reduces excessive reinforcing bar amount which can cause possibility of poor construction of concrete through design standard development and modular of nuclear facility structure using high strength reinforcing bar to raise economics and has its purpose to maintain high-level safety and durability as they are. This study is to introduce application method for the Rebar Modulation of High-Strength Reinforcing Bars to the Nuclear Power Plant Structures.
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Consider about aggregate's price, coarse aggregates from 13 to 25mm were widely used in ready mixed concrete company. But if only use 13 to 25mm aggregates in the concrete, gap grading problem would be occurred. When recycled aggregates from 13 to 25mm was used, continuous grading would increase the durability and strength for the concrete, meanwhile the construction waste materials would also be reused. In this paper, 5-13mm recycled aggregates was utilized, to analyse the fundamental properties for concrete, strength has been tested to evaluate the quality and reusing effect of the recycled materials.
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Nowadays, the fiber which mixed with concrete matrix always has low adhesion with cement paste. It's difficult to use fiber to reinforce the structure. For more adding fiber in concrete would cause some problems as the low flowability and surface polishing. Further study is needed in fiber using. In this research, further study in fiber reinforced concrete has been invested. Various fibers with different properties have been used to prevent cracking. Fiber reinforced concrete's fundamental properties as slump, air content, compressive strength and tensile strength have been tested. Optimum type of the fiber and optimum addition ratio of fiber has been invested to increase the utility of the fiber which used in concrete.
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In this study, the results are compared with the case of the concrete with embedded heating wire to verify the performance of the IB made in order to improve the workability and affordability, and to determine the effectiveness of early frost damage prevention. The IB was made using the 5W heating wire and layed on the upper surface of the concrete. The temperature was reduced to below 0℃ approximately within 24 hours, then approached the external temperature thereafter. On the other hand, when the 20W heating wire was used to make the IB and applied the same way, the temperature remained around -2 to 3℃ on the average even through the temperature was reduced to below 0℃, due to the heating wire with relatively large heating capacity. It appeared to reach 85% of the direct heating by embedding the heating wire relatively deeper in the concrete. However, it was determined that using the IB made with the 20W heating wire will prevent the early frost damage to some degree in -10℃.
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When concrete was hardened, it should had considered a crack to make internal stress by hydration heat. For control of crack, admixture was use to change cement because hydration heat was effect to cement. High strength mass concrete had much hydration heat with high volume of cement. It was necessary to reduce hydration heat in construction method. In this study, it evaluates hydration heat, compressive strength of transfer concrete girder regard to field construction type such as separation, whole etc. Also, we test compressive strength of concrete with core and mold specimen.
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In this study, characteristics of the concrete replaced in large amount with blast furnace slag is analyzed by the microscopic analyses in the process of the mock-up testing to apply to the actual practice in the area of the general strength by activating a small amount of cement(25%) replaced in large amount of finely powered blast furnace slag.
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This study was a result of laboratory test to confirm the porperties of concrete containing the domestic artificial lightweight aggregate. The domestic artificial lightweight aggregate is made with bottom ash which waste material in the thermal power plant. In the experimental result air contents of fresh concrete was measured lower than other artificial lightweight aggregate. This air contents is important for retaining the resistance of freezing and thawing. Therefore air contents of concrete will be considered for retaining the resistance of freezing and thawing when manufacture the concrete containing the domestic artificial aggregate.
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Kim, Min-Jung;Choe, Gyeong-Cheol;Yoon, Min-Ho;Ham, Eun-Young;Miyauchi, Hiroyuki;Kim, Gyu-Yong 34
In this study, the ultra high strength concrete which have 80, 130, 180MPa took the heat from 20℃ to 700℃ and the 0, 20% stress in normal condition's to evaluate stress-strain, residual compressive strength and thermal expansion deformation were evaluated. The heating speed of specimen was 0.77℃/min 20~50℃, 50℃ before the target temperature, and the other interval's heating speed was 1℃/min. As a result, the stress-strain curve of non-load specimen showed the liner behavior at high temperature when the specimen's strength increased more. If ultra high strength concrete got loads, its compressive strength tended to decrease different from the normal strength concrete. The thermal expansion deformation was expanded from a vitrification of quartz over 500℃. however, over the 600℃, it was shrinked because of the dehydration of the combined water. -
It is the study on the mechanical properties of the material when mixing hybrid fiber as steel and synthetic fiber to improve fire resistance and toughness of concrete. Finally, The purpose is to identify of mechanical properties of Hybrid Fiber-Reinforced Ultra High Strength Concrete such as flexural strength.
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In this study, in regard to fiber reinforced mortar mixing steel fiber and 4types of organic fiber, impact test was carried out. Because to predict fracture reduction performance with flexural, tensile strength when types of fiber were different as impact reduction performance of concrete is closely related with toughness such as flexural strength, tensile strength and fracture energy etc. As a result, enhancement of toughness by fiber reinforcement controls the spall of rear. On the other hand in case of steel fiber relatively turned up high toughness in appropriate load compared with organic fiber but in same mixing rate, impact reduction performance by projectile showed low performance due to few number of an individual of mixing.
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The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. but a few research projects on concrete compising more than 70% of outsider of buildings has been tried. This research is structural insulation concrete what improved insulation performance using micro form admixture and calcined diatomite powedr and lightweight aggregate.
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The study on annual evaluation of CO2 and general economic for precast concrete without steam curingNowadays, Precast Concrete is adopted on most of construction, because of shortening construction period and good quality. In precast concrete, steam curing is necessary for getting proper strength, but it causes much CO2 and economc. Therefore, on this study, by using type III cement and hardening accelerator, early compressive strength was shown 13MPa for 6hr. From the result, removal form could be shorten. Furthermore, annual CO2 was reduced as much as 24% and also annual cost was decreased as much as 12%.
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In this research, it is investigated strength development by replacement ratio of mineral admixture contents, types of superplastisizer and strength improvement material contents based on industrial byproduct to expand use of low cement concrete for typical floor.
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Evalution of Practial Application of high early Strength Concrete using Early strength type materialThis test investigates early strength and durability of concrete using early strength type materials(cement, Polycarboxylate acid). The goal of this test is to secure the strength of 5.0 MPa in 12 hours early age and strength of 14 MPa for 24 hours correspondingly. This type of admixtures, concrete curing temperature, amount of binder and other concrete properties were confirmed by experimental factors. Comparing outcomes from two cases on using early strength type materials and common materials resulted in reducing of costs and shortening of the construction period, that determined the economical benefits of using early strength materials in construction.
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In case of Korea, it goes frequently that underground parks has been burned. Based on standard temperature time curve(ISO-834), gerber, walls, slab of structures are constructed. However, Standard temperature time Curve is not considered that buildings are affected by vehicle fire. that is why it has the hazard that makes building reinforcement feeble. Based on the result that got from vehicle experiment before, we made four RC slab in this experiment and set the fire severity. according to the loading experiment after heating, we measured the effects that makes reinforcement and shape changes. Furthermore, we examined the safty of the structure by comparing before and after heating.
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According to the increases the standard of living of the people, requirements for building environments are also being diversified. The fungus that occurred the building is not good the health of occupants as well as undermine the value of the building. However, chemical antimicrobial agent contain ingredients harmful to human body and it has an impact on indoor air quality. Therefore, the use of natural antimicrobial material is strongly required. In this study, the fungal reproductive inhibit capacity was evaluated by using mortars with natural antimicrobial material.
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Recently, The economic growth has increased carbon dioxide emissions. so, It is caused by social problem to environmental damage and human health due to global warming. Accordingly, The method solution is to the amount of cement and to use industrial by-product such as Blast furnace slag, Fly Ash, and Red-mud. Thus, The purpose of this study is to analyze the physical property of concrete with red-mud. So, this study carries out the basic performance test of concrete such as, air content, slump, and compressive strength. In this work test is conducted according to sequence of materials using concrete twin mixer.
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In this study, in regard to concrete considering variety of admixture content rate, we evaluated property of adiabatic temperature rise. By setting up high temperature history, we evaluated effect to compression strength property of high strength concrete by early high temperature history. As a result, early high temperature history accelerated Hydration reaction of cement and contribute early strength development but it didn't accomplish performance objective in long-term aged.
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In this study, the standard specimen heated to curing experiments and simulation experiments the absence of porosity distribution and the effect on the compressive strength has been investigated.
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For reinforced concrete structures located in a sea environment, the Impressed Current Cathodic Protection (ICCP) is mostly used as a signature method to prevent steel corrosion. For this research, specimens to which the ICCP is applied were manufactured under the assumption of two following cases the specimens are exposed to various salt damage environments (submerged zone, tidal zone), and deteriorative factors (crack) occur in concrete. For the specimens manufactured, an enhancement experiment for deterioration was conducted through regular cycle change under the temperature between 15 ~ 70℃ with 70 ~ 90% humidity. Afterwards, the method effect was verified through a half-cell method and application of the ICCP derived from salt damage environments was investigated.
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Recently, people are concerned about how to maintain structure well because of safety. For effective maintenance of the structure, it should be resolved about carbonation, Durability, and Service Life issues. Solving that problem will Increase Safety of Structure. The carbonation velocity is produced an effect on carbon dioxide density of surrounding near structures, the concrete quality Therefore, This study compares the Velocity of carbonation due to maintenance of the structure. Also, this study will find Service Life of Concrete Structure through Predicting Carbonation Depth.
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Replacing a large amount of ground granulated blast furnace slag is limited because early age strength is low due to latent hydraulic property despite excellence of long-term strength. This study aimed to examine produceableness of high-activated ground granulated blast furnace slag using slag by-product from steel process. As experimental variable, the properties of strength development were analyzed by setting fineness and replacement ratio of slag by-product, curing conditions, and W/B. The results of study showed that high-activated ground granulated blast furnace slag using slag by-product as an activator improve the compressive strength of mortar. It is expected to be used as binder for secondary product of concrete considering curing and mixing conditions because high-activated ground granulated blast furnace slag can be hydrated by itself.
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Reactive Powder Concrete (RPC) is an ultra high strength and high ductility cement-based composite material and has shown some promise as a new generation concrete in construction field. It is characterized by a silica fume-cement mixture with very low water-binder (w/b) ratio and very dense microstructure, which is formed using various powders such as cement, silica fume and very fine quartz sand (0.15~0.4mm) instead of ordinary coarse aggregate. However, the unit weight of cement in RPC is as high as 900~1,000 kg/㎥ due to the use of very fine sand instead of coarse aggregate, and a large volume of relatively expensive silica fume as a high reactivity pozzolan is also used, which is not produced in Korea and thus must be imported. Since the density of RPC has a heavy weight at 2.5~3.0 g/㎤. In this study, the modified RPC was made by the combination of ternary pozzolanic materials such as blast furnace slag and fly ash, silica fume in order to economically and practically feasible for Korea's situation. The fire resistance and structural behavior of the modified RPC exposed to high temperature were investigated.
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In this paper, types of ready mixed concrete in construction site supported by different company has been researched. The practicability of the commercial available ready mixed concrete has been tested, and the standard deviation has been modified from Vc=Vo+3б to Vc=Vo+1.73б. Unnecessary premium rate has been cut and economical efficiency of the ready mixed concrete has been improved.
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The paper study on the mechanical properties of reactive powder concrete using copper slag. A change in the replacement ratio s of copper slag was measured compressive strength and slump flow. As a results, slump flow using copper slag tend to increase slump flow with replacement ratio. As the concrete with a replacement ratio of copper slag up to 30% was found to have a compressive strength superior to that of plain.
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The paper study on the mechanical properties of self-compacting concrete with waste marble powder. A change in the replacement ratio s of waste marble powder was measured compressive strength and slump flow, U-Box. As a results, Slump flow and U-box using waste marble powder tend to increase slump flow and compacting with replacement ratio. As the concrete with a replacement ratio of copper slag up to 10% was found to have a compressive strength superior to that of plain.
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A policy for recycling waste concrete has been extensively studied, but it is still lacking to recycle and reuse as a cementitious powder, and the property has big different depending on the aggregate rates. In this study, the amount of cement powder according to the internal properties of the aggregate were mixed. From as a result, Concrete Powder to play inside the aggregate composition of the cement composition CaO rigs that causes loss of power and strength reduction due to rising real water cement ratio will affect large.
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There is the increasing number of constructing soil or structure on the soft ground during public works. Usually cement or slag cement has been the traditional material for surface soil stabilization method. Recently, early strength development properties of hardening agent is required for driving abilities of execution equipment and shortening of the construction time. Therefore, the purpose of this study is to develop the early compressive strength hardening agent for surface soil stabilization. The study was confirmed performance and availability of hardening agent using early strength type cement and industrial by-product minerals through early strength development properties in accordance with water cement ratio, content of hardening agent for soft soil.
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Integrating multi-trade works system helps to reduce to minimize the conflict of subcontract business and improve communication to increase productivity of construction. However it takes such a big risk if subcontract of integrating multi-trade works went bankrupt during the project so some of construction companies executed to only small project and it's not sufficient to adopt overall project. This paper suggested the improvement scheme of work classification integrating multi-trade works, which takes a consideration into work zoning in order to apply current work situation.
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Construction data is one of the most important resources in a construction project. The construction data is generally stored in the PMIS. However, it has been analyzed that the PMIS revealed limitations in suggesting valuable information by analyzing the data. In order to overcome such limitations, the linked-data methodology used in big data management has been studied. The purpose of this study is to suggest a methodology that improves the system by developing a more effective data collection and management model using the linked-data format.
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For the purpose of launching strikes, initial survivability of self-propelled artilleries is of crucial importance despite the fact that they are mobility weapon systems. This study identifies the combat placement possibility of the reinforced concrete box-type artillery positions, which might enable the replacement of the current igloo-types, in terms of cost and protection capability. In the numerical analysis the obtained numerical values have proved that these facilities have sufficient protection capability. In addition, it could be concluded that these facilities are also cost-competitive, if more than five positions are constructed simultaneously.
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In the field of nuclear power construction, management and the systematic construction is very necessary. For more efficiently managing, analysis of influence factors and productivity is indispensable now. On this research, we collected the data from the nuclear power plant which is located in Korea. We analyzed the productivity and influence factors. As a result, productivity was 0.75(㎡/man·hour).On one hand, the productivity should be personnel, weather and whether there is a night duty or not. On the other hand, work crew depends upon operators, formwork amount, the presence or absence of night duty.
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Recently, a technique based on BIM has been rapidly increased on the construction project. Task such as a calculation of supply easily is proceeded by the technique. Also, an quick and precise preliminary estimate is possible because this technique can be applied. To sum up, this study suggests that the preliminary estimate based on a database of the BIM technique is applicable for the early stage of the construction project.
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Construction safety education plays role to provide necessary skills to workers for working safely. It is also important safety measure be used efficiently without any restriction to construction accident prevention. On this study, to develop effective education contents, we analyzed propriety of education contents used in construction sites, drew problem, and suggested the improvement direction.
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PC(Precast Concrete) technology has been widely used for reduction of construction period and manpower in domestic construction industry since it was introduced from advanced countries in the 1960s. But most of existing researches are shortage of research which proves the efficiency of PC methods quantitatively. Therefore, this study analyzed productivity targeting construction site workers who are working on projects using the PCF(Precast Concrete Frame) system out of PC methods that is used most typically in construction sites, and in order to provide basic data to prove the efficiency of PC project quantitatively.
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Recently, solar control facade systems are highlighted due to its low cost and outstanding applicability for green remodeling. However, it has not been long time since the systems were introduced. Therefore, the application study of the solar control system also has been insufficient. In this study, simulated models were developed and three types of solar control systems(i.e., overhang, blind, and screen)are installed in the models. The efficiency of energy savings and investment payback period according to the application of solar control facade system were analyzed.
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The use of inclinometer to measure deflections of structures is tested through experiments. By placing sensors at the ends of specimens, which are easy to accessed, the maximum deflection of a beam at the center is measured. Upon changing load, the inclined angles are measured and then converted to deflection using mathematical relationship between the deflection and rotational angle. Through this research, it is expected to promote the use of inclinometers for structural health monitoring of buildings and civil structures.
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The buildings constructed with steel structure is coated with certified fire resistive material to resist from fire. Coating materials lose their initial performances as time passes, so they need some maintenance. Fireproof spray-application also loses its performance and this performance loss of thr fireproof spray-application is very important because fire resistance of buildings depends on fireproof spray-application. So this study is to develop Acceleration durability test method of Fireproof spray-application, and use the Certification of fire resistant coating system.
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The purpose of this study is to characterize the bonding properties between reinforced bar and re-emulsion polymer cement mortar through the pull off test. The properties of polymer cement mortar before and after hardening were measured. Spiral reinforced steel bar was used to control the brittleness fracture of test specimens. In addition polymer content as experimental factors, the types of reinforced bar and corrosion were considered as well. Non linear FEM analysis was carried out to expect the behavior of bonding interface under the certain load.
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To join in the global trend toward the green growth, the government has chosen the technical development of a long-life housing as a national project and has been working on it. However, a research on its maintenance has been insufficient. Therefore, in order to come up with and support the systematic maintenance of long-life housing, I suggest the need for application of BIM by comparing and analyzing an apartment house and a long-life housing.
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This research studies in the field of domestic fires are an issue in many scientific fire research as a research method to validate the domestic environment and ISO-9705 housing on the basis of experiments in virtual space by making a single fire compartment space for conducting experiments and Appearance of a fire occurring within each flammable Heat Release Rate analysis was carried out mainly. Placed within the space of one flammable HRR calculated as the sum of the number of single-room fire experiments conducted and the results compared with the value in comparing the conduct of fire locations and fire load within the building area of the future, the HRR value represents the change in domestic a consideration of the safety of the building is to propose matters.
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For prevention of the school violence, many researchers have been conducted the studies based on crime prevention through environment design(CPTED) in the architecture planning phase. However, besides of architecture planning, the study considering the aspect of the facility management is needed during life cycle of educational facilities. In this study, the objective is to propose the effective school facility management for violence prevention based on CPTED method during life cycle of the facilities.
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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.
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The various photo data has a lot of information that had produce by the process of construction project lifecycle. Therefore construction site images is very important for effective management of the photograph information to transmit of accurate object information included in photography data. So the purpose of the study is to make application direction of intelligent image information that had image information in tandem with information of 5W1H for effective management of sites image in construction and maintenance phase.
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Many pictures are taken in construction sites. However, the pictures are not being managed effectively. In this study, the need for vector-photo have been raised which combines pictures and 5W1H information, and the vector-photo format have been suggested. A test module and user-interface have been developed for validating an utility of the format proposed.
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Apartment houses maintenance like remodeling in at issue and the importance is getting higher. On this study, we analyzed a variety of the influence factor affected building's maintenance expenses. circumstance influence factor about maintenance expenses is classified into region(big city, small and medium city), (area of high snowfall), (downpour region), (earthquake region), location(waterfront, inland province), using condition(mixed use, single use), frequency of use(kindergarten, middle school, high school), architecture method(reconstruction, construction).
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Huang, Jin-Guang;Park, Jae-Yong;Jung, Sang-Woon;Heo, Young-Sun;Han, Min Cheol;Han, Cheon Goo 126
For the decades, various of materials were used to instead of cement as the high volume CO2 occurred during the process of cement manufacture. In this paper, incineration plant ash was used in the mortar which incorporating high volume of blast furnace slag. Water to binder ratio(W/B) is fixed as 50%,BS+RP's replacement ratio is fixed as 80%,and the replacement ratio of WA1 is range as 0,0.5,1,2,3,4,5%.For the fresh mortar, flow and chloride contents has been tested. For the hardened mortar, compressive strength at 3,7,28 days has been tested. the result shows that when the replacement ratio of WA1 is 0.5%,the chloride contents is less than 0,3 kg/m3,the flowability and strength also performed better than other replacement types of mortar. -
Energy losses through windows and doors are big problems in the construction industry. For glass only, it has takes the largest portion of mass from window assembly and it responsible for 24 ~ 45% of energy loss from total building energy loss. Insulating glass unit should maintain their basic functions during their working life in order to contribute positively for global warming issue. There have been many research works for improving insulating glass unit durability. But it is not easy job to fulfill the requirements because insulating glass units composed of many components. So, overall it is required to have right qualify control procedures starting from material selection to fabrication, shipping and installation to the customer site. In this report, we have reviewed the durability of insulating glass unit made from different grades of sealing materials based on globally accepted industry codes such as EN1279. ASTM E 2190 and Locally available code. KS L 2003. The result showed that there is a relationship between the mechanical properties of insulating glass 2nd sealant and the durability of the units.
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External Insulation Method is to place the insulation on the outside of concrete. External Insulation Method is better than Internal Insulation Method to the protection of structure. However, The phenomenon that External Insulation falling from the structure occurs frequently. Apply method of External Insulation is divided Wet Construction, Dry Construction and Wet & Dry Construction. The purpose of this study is to test Bonding Strength of External Insuation. Furthermore, on the basis of this study, External Insulation Method determines the effective development will be made.
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In general, the seismic retrofit is almost essential to extend and remodel aged buildings. Because domestic seismic design code has been enhanced, seismic performance should be secure for aged building remodeling. Seismic response reduction device (damper) is lately appling to ensure seismic performance. This device is economical efficiency method that can reduce the load to foundation and the range of structural reinforcements, shorten of construction period. New shaped steel damper was applied for extension and remodeling construction for Boramae Deakyo building. As a result, the economy and shortening of construction period was achieved.
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Nowadays, research about using recycled aggregate as alkali activator has been investigated. By the mechanism of Alkali activation, blast furnace slag's potential hydraulis property would be activated. Thee application of this technique is considered as fit for low strength concrete, so it's suitable in concrete secondary production such as bricks and blocks. Aside alkali activator, sulfate could also activate blast furnace slag's potential hydranlis property. In this research, gypsum(CaSO4·2H2O)has been added with blast furnace slag. Fundamental experiment such as flow and strength has been tested to evalnate effect of gypsum's activation property.
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Ground source heat pump systems can achieve the energy saving of building and reduce CO2 emission by utilizing stable ground temperature. However, they have many barriers such as high cost of installation, incompletion of design tool, lack of recognition as heating and cooling systems. In order to solve the problems, the building integrated geothermal system (BIGS) developed by several researches which use building foundation as a heat exchanger. In order to establish the optimum design tool of BIGS with the horizontal heat exchanger, the prediction method of ground heat exchange rate developed with numerical simulation model. In this study, the economic analysis for BIGS was conducted based on simulation results and the optimal design method was suggested. As a result, it was found that the case of 32 A, piping space 0.3 m, piping deep 0.5 m and flow rate 9.52 L/min was the best case as 50.1 W/m2 of heat exchange rate. In this case the initial cost was reduced to 115 million won.
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The modular construction method have improved quality, reduction of defects, such as the reduction of air, a number of advantages. It is utilized composite, larger, in skyscraper building already abroad. The domestic, various studies have been conducted on technical matters taller, automation of production, such as process control, but is still inadequate circumstances. Therefore, in this study, is the purpose that you have presented activation measures to investigate and analyze the case of co-housing with a modular construction system of outside, and to make the co-housing of modular construction system of domestic.
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Unit module system produce units in the factory and assemble in the field. This unit module system has advantages of shortening the process of construction. However, it is still in the early research related to setting the unit module which is transported by truck to the field. Therefore, when transporting the unit module, this goal of study develops fixed devices. And suggesting device were performed that simulations analyzed maximum stress and assessed the safety.
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The oyster shells of about 240,000 tons have been annually produced in south coast of South Korea. However, about 25% of the oyster shells (60,000tons) was recycled as oyster seeding and fertilizer due to the limited amount of consumption for such purposes. The stored amount of oyster shell in the fertilizer manufacturing company is overfilled, and thus cannot accept any more of the waste oyster shells. As a result, landfill and illegal dumping of waste oyster shells have become an increasingly serious issue since 2011. In this research, the problems generated by the oyster shells were investigated through surveying activities. One of the possible alternative solutions that can process large amount of waste economically was found to be the application of oyster shells as a construction materials.
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Evaluation on the Properties of Mortar using Waste Shells for Partical Replacement of Fine AggregateRecently, the construction industry in South Korea, has experienced many difficulties in lack of supply with construction materials. Since waste shells can be possibly used as replacement materials of fine aggregate, the successful application can resolve, to some extent at least, the economic problems and environmental problems. In this research, the basic physical properties of the mortar which was used as fine aggregate substitute (clam, cockle, manila clam, oyster) were evaluated. According to the experimental results, the absorption rate and compressive strength of samples with various shells were equivalent to that of plain mortar. The mortar which replaced 25% of oyster shell with sand showed approximately 30% lower compressive strength and twice as much absorption as plain mortar. It was found that waste shells can be used as replacement materials of fine aggregate, but the oyster shell requires further experimental works in order for its successful application.
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Recently, the internal space organization of the building changes to the frame construction and flat slab construction in the wall type structure. And the use of light weight panel changing the internal joint use easily is increased. Therefore, in this research, the length change characteristic that the magnesium chloride addition rate reaches to the magnesium curing body tries to be studied. It could confirm according to the length change specific result that the magnesium chloride amount of addition reaches to the magnesium oxide curing body to expand. And the thing described below was the large-scale expansion the magnesium oxide addition rate 60%. And it showed up as 50, 40, 30, 20, and order of 10s (%). It could look at to form the hydrate of the SEM picture result needle-shaped of the Hardened.
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Based on the Fire Service Act of mandatory provision, new buildings are strictly forced to use fire protection materials. Flame resistant EPS is one of those materials. Unlike conventional EPS that can be fused to make EPS ingot and be recycled for various purposes, flame resistant EPS waste cannot be recycled due to the presence of protective coating that is applied to increase the fire protection properties of EPS. A suitable alternative that can process large amount of flame resistant EPS wastes needs to be developed, and one of the possible alternative is to use them as construction materials. In this research, experiments were designed to observe whether the flame resistant EPS wastes can be utilized as partial replacements of fine aggregates in cement mortar. The replacement ratio of waste EPS was varied, and its effect on compressive strength and absorption capacity was investigated. According to the experimental results, both compressive strength and absorption capacity met the Korean Standard specification for cement bricks and blocks, indicating that flame resistant EPS wastes can be used for construction purposes.
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The aim of this work is to have a better knowledge of reactions that take place in a cement paste, blast furnace slag mixed cement paste and fly ash mixed cement paste and know about the change in chemical components exposed to elevated temperature. The results show that the dehydration reactions appeared differently in the each admixture mixed cement paste and can be used as tracers for determining the temperature history of concrete after a fire exposure.
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As the chemical shrinkage and autogenous shrinkage of paste constitutes a large part of the shrinkage of high strength concrete, a good understanding of characteristics of chemical shrinkage and autogenous shrinkage is essential in order to understand chemical shrinkage and autogenous shrinkage of concrete. In this study, a preliminary study on effect of mineral admixture on chemical shrinkage and autogenous shrinkage of paste was compared.
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In this study, effects of supplementary cementitious materials(fly ash, blast furnace slag and waste glass) on drying shrinkage of cement mortar were compared and evaluated. The results showed drying shrinkage of cement mortar using blast furnace slag and waste glass is larger than shrinkage due to capillary pressure, while using fly ash is smaller.
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Recently, the enviroment problem is serious due to the global warming phenomenon because of the greenhouse gas exhaustion. In addition, the effort to reduce the problem in the situation where the severity of the destruction of environment because of the indiscriminate picking of the that is the raw material of the cement, Accordingly, in the interior of a country, the industrial site using the artificial stone instead of the natural stone is increased. Thus the cement reduction amount of use and substitute material research is the urgent actual condition with the gas emission, which here it is generated in conducting compression molding in the building stone manufacturing process performance degradation phenomenon and fire resistance, and problem of the durability. limestone and aggregate and exhaustion of resource are emphasized is continued. In this research, the fly ash and waste porcelain is applied to the magnesia phosphate composite (MPC) and the characteristic of the artificial stone according to it tries to be looked into.
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This study is on the performance evaluation of concrete being used the CaMg based low carbon cement(LCC) as a binder and the rapidly cooled electric arc furnace oxidizing slag(EAF slag) as a fine aggregate. When using the sand as a fine aggregate, compressive strength of the concrete using LCC, as a binder, was reduced 9% comparing with that of OPC concrete. However, when using the EAF slag as a fine aggregate, the compressive strength was increased by 9%. We found that combination LCC and EAF slag contribute to the strength properties of concrete.
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Bottom ash, which is discharged through a wet process in a thermal power plant, contains much unburned coal due to quenching and much salt due to seawater. However, dry bottom ash discharged through a dry process contains low unburned coal and salt, and has light -weight due to many pores. Therefore, it is expected that it can be used as lightweight aggregate. This study deals with the basic properties of concrete used dry bottom ash as coarse aggregate. As a results, the concrete having high content of dry bottom ash aggregate showed high slump by using water reducing agent and its air content was within 5±1.5% as designed value, similarly to normal weight concrete. It also showed a lower compressive strength than 100% of crushed stone.
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In this study, the chemical resistance of polyurea resin waterproofing and anti-corrosion materials that is applied to the social infrastructure was analyzed. The result in this study will be utilizing as a basic data for establishing the quality standards which are able to judge the chemically resistant characteristic of polyurea resin waterproofing and anti-corrosion materials.
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To be applied to a humid environment such as bathroom and kitchen, sealant should have good adhesion, tensile strength, etc., it also have the resistance to fungal contamination from the environment. It is important to select right material for sanitary sealing application in order to prevent premature discoloration and fungal activities. Especially for high humidity conditions, it is crucial to have longer mildew and fungal resistance. In this article, we intended to give guide lines for developing right sanitary sealing material and practical test method for evaluating anti-fungal performances reflecting Korean residential life style.
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In this study, the tensile properties of sealants by heat deterioration were measured and analysed to gather the basic data of sealant because these studies do not have been investigated in Korea. Most general one-component silicone sealants were used and test specimen was I-type. The test parameters are sealant types which have different density and heat deterioration time in 80℃. As a result, the rat of reduction in area by heat deterioration was considerable increased at SR-A compared with SR-B. The tensile properties by heat deterioration decreased at SR-A because the specimen by deterioration occurred adhesive failure before tensile test. However, SR-B specimen was increased at maximum tensile stress but decreased at elongation in maximum tensile stress. Also, Maximum principal stress was measured at the edge of specimen by FEM simulation in order to find out failure points.
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Nowadays, energy-saving has become important in the construction industry. Above all things, outside insulation on buildings is important in measure of energy-saving. However, its insulation performance is degraded by the problem of that Cement-polymer modified waterproof coatings are used mostly for covering plaster mortar. In this study, we examine the optimum size of the silica and how does silica's size effect on physical properties of outside insulation covering plaster mortar.
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Steel structures of the seaside area are naturally led to surface corrosion due to incoming salt. Signature measures for this are to replace steel with steel material with a high corrosion-resistance and to block salt and other deteriorative factors beforehand through finishing work such as surface coating. However, the variety in steel materials, finishing type, and construction methods makes adhesive weight of incoming salt different depending on each type. For this research, measurement results derived from an enhancement experiment on artificial incoming salt adhesive to 4 steel finishing types and 2 material types identified a difference of adhesive weight by each sampler.
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Many kinds of fire-stop sealants have been used for joint sealing, cable penetration part sealing and fireproof structure finishing etc in building sectors which need water-proofing and fire-stop properties. But, fire-stop sealant itself has no specific industry standards in Korea even though there are so many required properties for the application. So, in this study, for the evaluation, we adopted and applied UL standard 94(UL 94) which is commonly used for the fire retardant testing in inflammable materials like plastics and rubbers in electronics industry. In this study, we demonstrated fire resistance properties of each fire-stop sealants which varied with different formulation, thickness and origins available in Korea. Overall, fire stop sealant had better fire resistance performance than normal construction sealant. And the thicker the material, the better the fire resistance performance was. Because there is no national or industry guideline for fire stop sealant itself, each sealant products showed different level of performances under UL94 desigation. Even certain product had very poor fire proof propeties although it claims it can be used for the application.
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Concrete filled steel Tube(CFT) columns have great strength but also fire resistance performance due to the heat storage effect of concrete. In this research, we focus on the fire performance of CFT using 100 MPa concrete without fire protection. We use steel fiber and nylon fiber for fire resistance. We perform the fire test of CFT specimen with loading 200, 300 and 400 ton. To investigate the effect of loading to fire resistance, we compare the fire resistance time according to the loading.
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Recently, high fluidity concrete is becoming more prevalent. High fluidity concrete uses admixture or thickener in order to prevent separation of materials due to increased fluidity, and, especially, BS is becoming more use for reduced heat of hydration and improved long-term strength. This study examined the effect of BS on fluidity of cement paste from a rheological viewpoint. As for BS types, materials equivalent to 1 types of KS F 2563 and the cement mass was substituted by 20, 40, 60, 80%.
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The purpose of this research is to comprehend experimentally the characteristic of human dynamic load and provide the result as basic data to suggest a valid impact-resistance evaluation method. Human motions exerting dynamic load are classified to 3 types. Selecting 3 ranks of motion strength, 3 ranks of load plane stiffness (A:20kN/cm, B:4.7kN/cm, C:2.2kN/cm), and 30 male grownup inspectors in their twenties, load was measured when they applied force on load plane. Result of this research is as follows: (1) Human dynamic load has different nature from object collision in the highest load ratio depending on the load plane stiffness and action time (2) The highest load ratio for each motion was 10.06 for kicking, 4.44 for hitting with shoulder, and 5.58 for fist blow.
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In this research, the fundamental experiment for colour concrete(by using pigment) has been invested. Fundamental properties and dyeability for the colour mortar as the changing replacement ratio of pigment has been tested. For the conclusion, with the increasing ratio of pigment, the flow and compressive strength for the mortar has been decreased, For the dyeability, there's little difference when replacement ratio of dyestuff changed when the colour is red and yellow, but large difference when the blue pigment was used. Consider about the workability and strength of the mortar, the optimum pigment's replacement ratio is fixed as 2.5%.
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The purpose of this research is to comprehend experimentally the nature of human static load to wall for making use of the result as basic data to evaluate resisting force of lightweight wall. Human motions exerting static load are classified to 4 types, and two-hands pushing and shoulder pushing are defined as the instantaneously forcing motions with hands or shoulder put on the load plate, respectively. Back leaning and one-hand leaning are defined as motions of taking a rest in their respective comfortable posture. Measurement of static horizontal load caused by each motion showed that the highest load ratio depends on hardness of load plane and was 1.17~1.25 times of weight in two-hands pushing, 0.95~0.99 times in shoulder pushing, 0.16~0.18 times in back leaning, and 0.12~0.15 times in one-hand leaning.
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Recently, it is the tendency that the CO2 gas generated in the manufacturing process is increased every year in case of the portland cement used in the most of constructions and civil engineering field. The method that uses the mineral admixtures as the cement substitute material in order to be more serious and as much as it occupies 7% of the global CO2 gas outlet amount such as 1 ton produces the cement and it ejects the CO2 gas of 0.4~1.0 ton, etc conclude this problem is examined. Therefore, PVA fiber was mixed into the inorganic binder recycling the blast furnace slag, which is the industrial byproduct with the purpose studying the Geo polymer which doesn't use the cement at all silica fume, red mud, and etc. In addition, the water curing temperature was differentiated and the strength characteristic of the curing body tried to be examined.
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This study is the experiment for manufacturing the Lightweight non-cement matrix based on the Blast furnace slag. And, the matrix was manufactured matrix by generating the bubble just by the reaction of KOH that is the alkali accelerator and paper ash, instead of the general foaming agent, that is the waste managed of incineration the pulp sludge generated in the process of manufacturing the paper. Consequently, the density according to the addition rate of KOH represented the tendency to increase. And it showed up that density of the matrix adding KOH 22.5% was the lowest. As to the strength test result, strength following addition rate of KOH increased. Since the bubble is generated in the reaction of KOH and paper ash, this shows the very low intensity but it is determined to be the result that the amount of vacant space is decreased because the bubble generated in the mixture process comes up as the specific gravity difference.
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To prevent energy waste in buildings used heat insulator. Heat insulator materials can be classified inorganic and organic. The inorganic material has lower water resistance. The inorganic material is heavy and worse thermal performance than organic materials. Technologies on energy saving and materials used in curtain walls have progressed with increase of high-rise and large buildings. However, there is little study to explain water resistance performance of the curtain walls. This study focused on evaluation of insulation of inorganic materials and performance evaluation by thermal conductivity.
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This study is interested in manufacturing the concrete surface impregnants including tetra ethyl ortho silicate, alkali silicate for the repair of the exposed concrete and the color concrete requiring the advanced function in view of the concrete appearance. The surface layer change and porosity properties was tested for the review of application. The result of this study show that the effective silicate are tetra ethyl ortho silicate and alkali silicate t. The adhesion in tension is slightly increased but the reinforcement of concrete substrate is slight. So, the concrete impregnant of this study is more desirable for the improvement of durability rather than the reinforcement.
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The rational Management of the school facilities will be able to minimize the waste of budgets, enhance total values of facilities. The purpose of this study is to propose promotion plans of the private infrastructure investment in the school facilities not only for contemplating obstacle reasons of BTL projects, but also for gripping contents about process of BTL projects. To achieve these objectives, this study 1)analyzes the major trend about private infrastructure investment, and 2)suggest extended suggestions for minimizing problems in the process of BTL projects in school facilities.
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In the recent years, the subject of the M&A of construction company has become one of important issue in the domestic construction industry. Therefore, the purpose of this research consider the rational plans of M&A not only for systematizing types about process of M&A in construction industry, but also for analyzing the significant characteristic of M&A in korea. To achieve this objective, this research performs a case study of M&A to embody the major trend and implications. The results of this research based on this methodology can be systematized as falling into two areas : 1)the primary types of M&A were divided into 4 categories by analyzing the results of interview, 2)the process of M& A from the result of case study.
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In recent times, the legal management of construction enterprise has become one of important theme in the domestic construction industry. Therefore, the objective of this paper is to consider rational methodology of legal management of construction enterprise. To achieve this objective, this paper performs a case study about the major cause and significant characteristic of the legal management. In conclusion, the following factors are systematized : 1) actual condition of legal management of construction enterprise in korea, 2) the influence and extended suggestions of legal management.
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The purpose of this research is to perform a case study for verifying problems of BIM application to the building construction project using Fast Track method. The object of case study is an actual construction project completed in 2013. As a result, some problems and solutions for those were extracted. The result of this study will contribute revitalization to the BIM application in the project using Fast Track method.
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The constructability of Formwork has a importantly influence on the duration and cost in a construction project. However, the existing studies on the formwork are mainly focused on a method of construction. Although a layout planning of forms, especially, is an important factors affecting the constructability and cost, it is done by engineers empirically and intuitionally after completion of structure design. Therefore this study suggest a decision support model for optimal formwork layout model based on the rearrangement of structural members by using Genetic Algorithm to improve constructability of formwork.
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Recently, Construction industry has been trying to reduce environmental impacts reflecting the global trend 'Green Growth'. However most of previous studies focused on operation & maintenance phases and do not have been approached construction phases. In addition, environmental management factors by project participants are assessed with only weight of factors, overlooking these work difficulty. Therefore This study aims to deducted the critical environmental management factors by project participants considering work difficulty in plan, design and construction phase. The basis data is collected through literature reviews and interview targeting each project participant and analyze these data using importance-difficulty analysis(IDA).
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The objective of this study is an assessment of competitiveness in construction infrastructure by nation in order to provide preliminary data of government policy. Key results indicated that out of 23 countries, Korea's construction market size ranked 11th, construction market growth rate ranked 16th, market stability ranked 14th, construction risk ranked 4th, construction system ranked 10th, ICT ranked 1st. And Korea was ranked 10th in overall construction infrastructure competitiveness by nation.
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Exterior walls are designed and constructed through design focused exterior wall system. Nowadays, freeform facade design has been changing according to material, form and function of the exterior wall system. Especially, curtain wall facade system is designed and manufactured using solar shading faces. However, the traditional method have a lot of difficulties in the currently performing technology for curtain wall facade. It is important to make the freeform facade components that integrated as a surface of freeform buildings. Therefore it is necessary to develop unit module construction method for freeform facade.
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Most of the building exterior wall cleaning robots use a water jet device for spraying water. However this method is sprayed excessive water usage than water quantity required for cleaning. And setting weight of the water pump cleaning device increase the weight of the building exterior wall cleaning robot. Therefor, this paper suggest that the mechanisms scatter minimal cleaning water using a spinning device of the building exterior wall cleaning robot.
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Korea rapidly arranged urbanization and overpopulation with high growth of economy and all kinds of decrepit facilities are scattered all over the downtown. If there is a strong wind in fire, fire is rapidly increased by various fire spread factors. And Korea cannot build prediction model of urban fire combustion phenomena because there is no studies that physically explains the suitable flame phenomena for its real state. In this study, based on the Japanese Urban fire simulation to target the building congested Area and suitability of fire risk assessment were reviewed.
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As the rapid and various changing of social aspects, the structures are getting bigger, higher and more complex. This study is research trend of fire safety in high-rise buildings to Asia country. Research Trend for the Fire Safety to present the plan to clean up the problems and ways to improve future domestic.
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A fire outbreak in a reinforcement concrete structure looses the organism by different contraction and expansion of hardened cement pastes and aggregate, and causes cracks by thermal stress, leading to the deterioration of the durability. So, concrete reinforcement structure is damaged partial or whole structure system. Therefore accurate diagnosis of deterioration is needed based on mechanism of fire deterioration in general concrete structures. Fundamental information and data on the properties of concrete exposed to high temperature are necessary for accurate diagnosis of deterioration. In this study, consider case of investigation methods and repair work in fire damaged structure concrete.
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Recently Korea has imported and executed Performance Based Design for the method to settle the dangerousness on outbreak of fire of high-rise building. The overseas country's PBD is autonomic but It is unable to carry out the essential role of PBD as the performance based design that based the code based design in the domestic. Also It occurs the problems that different the classification standard of building as dualisation between the building code and the fire services act. In this study, We have investigated overseas's cases for the PBD of high-rise building and have drawn the improvement direction & the problem of domestic's PBD by comparing and the analysing the domestic regulation.
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Recently, interest in renewable energy is rising in rural areas in order to reduce heating and air-conditioning costs which are directly connected to farmhouse income. Thus, in this paper, I study renewable energy supporting projects in rural area: I analyze distribution of the Agriculture & Fishery Energy use Efficiency Project and 1 Million the Green Homes program by using project performance data and the data of Korea Energy Handbook. The results of my analysis of the two programs show that, while annual average increase of the 1 million Green homes prgram is 15.6%, the distribution rate of heating and air-conditioning facilities using geothermal heating and cooling system of the project has decreased by average 37% every year.
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The fire safety design of performance is fire behavior inside buildings must be scientifically described and systemized as a theory, thereby allowing application to fire safety design of buildings. In this study, experiment of fire behavior according to disposition of combustibles were performed for correlation analysis between flashover and smoke production rate in building structure. As a result, smoke production rates is happened more than 80 m2/s in compartment(ISO 9705). Also, even if the fire load for flashover to if occur smoke did not, which confirmed that the delay time of occurrence.
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A study on the fire scenario proposal of residential facilities by using fire statistics. as a result of analyzing residential facilities fires by using fire statistics of national emergency management agency during 2007~2012, fires from carelessness were the most causes. specially, fires during food cooking among carelessness showed the highest occurrence frequency, and followed sparks, neglecting fire sources, and cigarette stubs in order. through this the study suggested fire scenarios according, It is believed that can be used as basic data for applying a secure building in a fire using a basis for fire safety design of buildings in the future this.
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The maintenance management in buildings has got more important by the increasing complexity of building sizes and use. Nowadays an expectation and a possibility of BIM technology become accepted as a new construction management method, therefore many studies and legal systems of it are being suggested actively. Although orders for BIM projects are supposed to be increasing, at present the BIM information accumulated from planning and design still doesn't have its continuity at the maintenance step after completion of construction in terms of LCC. Therefore according to bim information, we set a goal of developing apartment maintenance system which is able to maintain by user viewpoint.