Repeated using carpentry workers work at working tools because of occupational low back pain, such as musculoskeletal disorders, occupational diseases are on the rise. For this purpose, through the analysis of musculoskeletal disorders and work tools and studies are underway to improve the working conditions of the workers. However, existing previous studies may not reflect the working tools used for carpentry worker dies when working at a construction site that Therefore, in this study, the work in the form of construction, one of the jobs of worker dies classified according to the working tools of musculoskeletal disorders correlated to analyze. The results of this study are as follows. working tools of a total of seven different dies used in the installation process. Musculoskeletal disorders, waist / drill such correlation was very strong. Also showed that a total of three of the tools used in the formwork dismantling cutter musculoskeletal disorders of the arm / elbow and a very strong correlation.

Efficient operation of construction equipment has become more and more important in the competitive construction environment. Accurate measurement of performance rate of construction equipment is a critical factor for a construction project planning. However, it might be quite difficult to measure the performance rate due to diverse practical limitations such as continuously variable performance rate of construction equipment, considerable indirect cost, large construction field, and so on. Therefore, the purpose of this paper is to propose an automatic algorithm that measures a performance rate of construction equipment with a multipurpose composite sensor. It is expected that the algorithm compiles database on construction equipment and in advance, facilitates efficient operation of construction equipment.

This study investigates the temperature rise of reinforcement bars located in the middle of the form (for reinforcement concrete) during hot weather condition. The temperature was measured for three consecutive days before placing concrete. Test results showed that the temperature started to increase at 7:00 AM before sun rised, and peaked at around 2:00 PM. It was found that the thinner the diameter of a reinforcement bar, the higher is the speed of temperature rise and drop of the bar. The peak level of temperature for D13, D19, D25 and D32 was 54.4℃, 55.2℃, 56.4℃ and 60.2℃, respectively.

This study investigates the effect of adhesive type applying to surface-strengthening Ondol floor on level of attachment. Adhesive materials of four types produced in different companies were prepared and their attaching performance was examined. Test results showed that the water-based epoxy type produced in S company was the most effective on attaching the pieces of the surface-strengthening Ondol floor product.

The estimation of crack damages is studied using the radio frequency system and tilt switch sensors in RC beams. If load is received on the center of the flexible specimen, sensor housing using cement mortar of the flexible specimen will be destroyed, and these are become to send signals of damages at the radio frequency system connected with tilt switch sensors. This study is fundamental research for the estimation of the damage using tilt switch sensors in RC beams.

Moisture condensation leading to defects that occur repeatedly in the winter, and recognize the same method, the problem of the other buildings in the same area again and again, a vicious cycle that occurs due to the temporary lack of systematic research and processing way of coping has been recurring. In this study, as warming progresses, more inside the air-conditioned summer season due to an increase in the ambient temperature of the condensation phenomenon to happen about summer wall condensation phenomena are expected to analyze the case of a building to prevent condensation and for insulation designs are proposed.

This paper was to investigate the effect of incinerator ash on engineering properties of the high volume blast furnace slag concrete through Mock-up test. Test results revealed that the use of recycled aggregates resulted in increase of slump compared with the OPC concrete. But, the use of recycled aggregates did not affect the results of air contents and chloride contents. The use of recycled aggregates showed shortening of setting time of high volume blast furnace slag concrete. When the recycled aggregate was used, delay in strength development at early age happened with high volume blast furnace slag concrete compared with that of OPC concrete.

Because Self-Adhesive Waterproofing sheet has good constructability, it has been widely used. Also Self-Adhesive Waterproofing sheet is researched based on variety of materials and various of forms. However, producers have recognized about only pass KS quality standard. So, Self-Adhesive waterproofing sheet has been limited about improvement of performance. Therefore, in this research, proposed guideline of Self-Adhesive Waterproofing sheet for disinterested performance grade using probability theory and quality management theory.

This study is to low-temperature in using self-adhesive waterproofing sheet. Using self-adhesive waterproofing sheet is very comfortable in a waterproofing construction site. However, when self-adhesive waterproofing sheet is constructed from a low-temperature environment, there has been a attachment strength shortage. Therefore, this study on the attachment strength of self-adhesive waterproofing sheet is to investigate the low-temperature in the environment.

The construction industry is hard to apply to the statistical methodology of 6-sigma. For example, it is hard to verification of fraction defective through quantity production. So, in this research the proposed approach for effective process of technology development through establish of innovative methodology reflecting constructional characteristics. Few studies have progressed in construction industry, but there are so many examples using 6-sigma for applying to customer needs at the product development or process improvement in manufacturing business. So this research proposed the design methodology using QFD of 6-sigma and TRIZ.

Spacers which we have studied is the secondary product of the concrete to apply on concrete structure. It is needed to secure equal or greater performance than structural concrete that it is applied. There is a tendency that concrete structures are strengthened more and more. Therefore, designed set up position of reinforcement is used more and more, so it is needed increasingly high strength spacer. We have been doing a series of research to develop the different typed high strength spacer having crack resistance during constructing. The bearing load of different type spacer shows approximately 35% lower load than those in the general spacers.

Pusher-Loaded Scrapers are important construction equipment for large earthmoving operations. Production rates of a Pusher-Loaded Scraper vary greatly in accordance with the temperature or elevation, the equipment performance, haul speed, haul-road conditions, the method of loading, and Number of scrapers per one pusher. Determining of most economical scrapers fleet regarding the size of equipment, model name, and number of scrapers demands time-consuming calculation because it needs to reference of varied performance charts or tables and repeat complicated calculation. In this study, decision-making support system for the Optimal Pusher-loaded Scrapers Fleet is suggested for the purpose of calculating easily and handling effectively variables which are changed depend of the work conditions. The prototype of this program is developed using MATLAB. And the Database of Pusher-loaded Scraper embodies Performance chart & Retarder chart, soil properties, and calculation-support table.

Deterioration factors such as CO₂ and chloride ions cause steel corrosion in RC structures. The diffusion of these factors depends on the water content in concrete. To examine the moisture condition of concrete, this research considers the availability of the steel effect ratio, which is calculated by Resistivity Estimation Model (REM). It is concluded that the steel effect ratio is expected to be available as a quantitative evaluation method in the assessment of concrete layer resistivity.

This study is intended to use the insulation effect of the dual bubble sheet to review the freezing prevention capability of underground walls by pouring the dual bubble sheet on the retaining walls before the concrete pouring to contemplate the temperature profile for each area of installation and the area of non-installation of the dual bubble sheet, and as a result, the temperature of the concrete was heightened than the ground due to the insulation effect in using the bubble sheet.

Under this study, the characteristics of concrete intensity condition following the curing method under the extremely low temperature environment have been contemplated, and as a result, in the event of insulation + heat cable curing, the intensity and accumulated temperature accomplishment period is required for two times of requiring initial frost damage prevention than the case of heating + heat insulation curing method due to the insufficient calories supplied in general.

This paper is to report the results of mock-up test for concrete during severe cold weather. The temperature is fixed at -20℃. The mock-up specimens were fabricated simulating slab, wall and column. Heating coil with different heat capacity with 5 W and 15 W were embedded at slab specimen. Test results revealed that at -20℃, temperature dropped below 0℃ since around 70 hours. It takes 7 days to gain 45°D·D of maturity for avoiding frost damage at early age.

In this study, the field applicability on reducing the heat of hydration of mass concrete by using the hydration heat difference method is analyzed with the following summary. As a result of applying the hydration heat difference method by using low heating combination, the temperature difference between the central part and the surface part of mass material was reduced, and as a result of visual observation, there was no showing of cracks by the hydration heat on the upper surface part. Therefore, the cracking index of the field to apply this method was shown to be approximately 1.57 with very little crack occurrence probability of less than 3%.

This study is for analyzing possibility of utilizing as cement from waste concrete. The scrapped fine powder which contains a large amount of hydrate of cement can supercede lime stone, and greenhouse gas reductions are expected. However, Fine Aggregate powder efficient separation technology development is essential for that limestone substitution effect and reduce greenhouse gas emissions in order to facilitate through the recycling of the scrapped fine powders.

Recently, Fire-proof performance of buildings becomes important to ensure safety. As a result, fire-proof paint is required for 3 hours. However, Experiments are only performed by standard KS F 2271 for estimation of fire-proof paint. Because there is no domestic estimation standard for performance of fire-proof paint as well. So estimation standard of fire-proof paint is needed to guarantee their performance for establishing quality system and to assure same performance for safety of people in the building from unpredicted fire accident. Owing to these reasons, we studied comparative estimation for quality performance of two kinds of fire-proof paint and bond performance.

The cement used in the construction industry of the manufacturing process, large amounts of the greenhouse gas, CO₂ and is currently being studied for cement substitutes that reduce greenhouse gas issue. Therefore, the this study as a replacement for cement industrial by-product of blast furnace slag, red mud, silica fume and alkali-activator, using only inorganic composites without high-temperature calcination process were manufactured. The waste gypsum board micro powder added to compensate for the shrinkage cracks, the compressive strength and flow, and length change characteristics were investigated. Consequently, The setting time was shortened as GB added And liquidity was reduced. GB 2%, 7 days curing the added strength of specimens was the highest. Came out, and change the length of the Plain least.

This paper is to investigate the effect of waste oil on the fundamental properties of high volume fly ash concrete depending on W/B and waste oil contents. Test results reveals that the use of waste oil resulted in an increase of slump and a decrease of air contents due to the presence of emulsion in waste oil. And it is found that the addition of waste oil does not affect the strength development of the concrete significantly.

The purpose of this study is to evaluate the depth of carbonation considering the relative humidity in concrete using the FEM model. The difference of relative humidity in concrete has not been considered in calculating the carbonation depth in analytic model. That reason can make the over estimation in expectation of RC structure durability. The temperature and R.H. expectation model and the carbonation depth expectation model are development in past author's studies. The two models are coupled in this study. The fact that there is the difference between actual environment and acceleration test is revealed from FEM numerical analysis.

The elastic modulus of recycled aggregate concrete (RAC) can be evaluated by using composite models with experiment. In this study, Hashin's composite model was adapted to evaluate elastic modulus considering physical properties of recycled coarse aggregate (RCA) that mortar is attached. Elastic modulus testes for cement paste, mortar and recycled coarse aggregate concrete were carried out considering W/C and recycled coarse aggregate content rate. As a result, the elastic modulus of RAC was evaluated comparing with both experiment results and the existing estimation formula. Those can be used for further studies as a preliminary data.

In this study, it was evaluated about creep properties of high strength concrete according to compressive strength and moisture evaporation condition. As a results, creep strain and creep coefficient was greatly affected by moisture evaporation conditions rather than compressive strength. Also, the effect of fiber mixed was not show big difference.

This paper intends to review possible application in the high strength area through compressive strength estimation of the simulated high strength concrete member using Rock Test Hammer and suggest it as a reference data for the strength estimation technique of the ultra high strength concrete in the future. From the results of our test, in the low strength area less than 15MPa and normal strength area in 15~60MPa, as shown on the existing studies, it is indicated that P Type Schmidt Hammer in the low strength area and N Type Schmidt Hammer in the normal strength area have high correlation of rebound-compressive strength. As the Rock Test Hammer indicated more or less reduced accuracy in the low strength area and the normal strength area but high correlation on the high strength area (50~100MPa) defined on this test, it is determined that it would be possible to make the fastest and simplest compressive strength estimation on the site where the high strength concrete is applied.

The purpose of this study is the hydration properties of motar using Blast-Furnace Slag(BFS) with water elured from recycled coarse aggregate. The results of the experiment show that the water eluted from recycled coarse aggregate mixed with blast furnace slag has comparatively higher hydration activity than the mortar not mixed with one in early-age mortar causing the calcium hydroxide in the recycled coarse aggregate to work on as a stimulus to the hydration of ground granulated blast furnace slag. BFS mixed with the eluting water the hydration reaction was a promotion.

Lately, the scale of the primary energy consumption in Korea is ranked 10th in the world, and it takes up about 1.9% of the entire energy consumption in the world. And among total energy consumption in Korea, the ratio of the part corresponding to the residence or commercial buildings is about 30.5%. Also, with the increased interest in eco-friendly buildings, the production of eco-friendly building materials consisting of them also increases as well. However, since the process of their production generates much energy consumption, so this is being raised as a social problem. Therefore, this study suggests a method to improve thermal performance by using eco-friendly earth plastering materials and natural materials in order to reduce energy consumption in buildings. The experiment evaluated thermal performance by measuring the external and internal temperature of the curing after the plastering of 1cm in the wooden box of 30cm * 30cm * 30cm. As a result, there was difference in the order of powdered coal, pealite, chaff, and rice straw. Among them, powdered coal indicated excellent thermal performance. This will be the foundational research used to improve interior environment and reduce heating bills.

The purpose of this study is to investigate the mechanical property and carbonation resistance of concretes using surface treated lightweight aggregate. In order to evaluate mechanical property and carbonation resistance, slump, compressive strength, and carbonation depth are tested. Slump of concretes using surface treated lightweight aggregate measured 120~125mm, which are lower than slump of NWAC. Compared to compressive strength of NWAC, compressive strength of concretes using surface treated lightweight aggregate showed a level of 82.8~95.9%. In carbonation resistance test, carbonation depth of concretes using surface treated lightweight aggregate measured 10.2~11.3mm, which are lower than carbonation depth of NWAC. As a result, it is found that compressive strength is decreased slightly but carbonation resistance is improved, in case of using surface treated lightweight aggregate.

In this study, prediction of later-age compressive strength of ultra-high strength concrete, based on the accelerated strength of concrete cured in 80℃ warm water was investigated. As a result, the nature of ultra-high strength concrete showed a rapid early strength enhancement, compressive strength using warm water method of 80℃ at 2days is same compressive at 28days using standard curing.

This study makes with the environment-friendly artificial stone which doesn't use the cement and natural aggregate and increases the blast furnace slag that is the eco-friendly material that is the industrial byproduct, fly ash, and availability of the red mud and applies the coares aggregate substitute material as the cleistothecium. The experimental plan according to it indicated the compressive strength and flexural strength which is the most excellent in the mixied ratio 40% of the result degree of closeness magnetism of experimenting with the optimal mix obtained through the preceding stude.

This research examined the fundamental property of the MgO as the fundamental study that substituted the MgO in the low melting point modified sulfur mortar to examine the physical properties.In this research, the table floor, flexural strength test, and compressive strength test were performed. And as the replacement ratio increased, the floor showed the tendency to increase. And when being the replacement ratio 3%, the flexural strength and compressive strength made the high strength. In case of being substituted for over 5% they displayed the tendency that the intensity is degraded.

Aggregate thermal properties and cooling methods are most important to evaluate the residual mechanical properties of concrete. In this study, we evaluate the residual mechanical properties of concrete according to the aggregate type and cooling method. We use the normal weight aggregate and light weight aggregate which have different thermal properties. After heating to the target temperature, we evaluate the mechanical properties according to the slow and fast cooling condition. As a result, normal weight aggregate concrete has higher effectiveness of cooling conditions than light weight aggregate concrete.

In this study, it was evaluated about hydration heat reduction under hot weather condition. Placement temperature set 25℃ and 35℃, For hydration heat reduction was applied such as FA and BFS. As a results, mixture of BFS70% is the most effective hydration temperature reduction.

With blast-furnace slag is a by-product generated when pig iron is produced. It has been used as the concrete admixture due to high reactivity. However, It causes low strength development during early age. In order to make up for this drawback, in this study, we evaluated compressive strength of mortar replaced with high volume blast-furnace slag. Experimental results, Compressive strength of mortar based on blast-furnace slag is affected by cement type, substitution rate of blast-furnace slag and pH after mixing.

The study on the strength prediction using Maturity is mainly focused on, but the study on the concrete mixing blast furnace slag powder is insufficient. The purpose of this study is to investigate the relationships between compressive strength and equivalent age by Maturity function and is to compare and examine the strength prediction of concrete mixing Blast Furnace Slag Power using ACI and Logistic Curve prediction equation. So it is intended that fundamental data are presented for quality management and process management of concrete mixing Blast Furnace Slag Power in the construction field.

Korean government is planning to supply a half million public and permanent rental houses from 2013 to 2018 for settlement of non-homeowners. It is requested an objective criterion to appropriate the budget for the rental houses construction project cost. In this study, construction cost indices, which reflect the inflation trend of construction resources, were explorated to suggest a effective methodology for the construction cost estimation of therental houses. We figured out the future construction cost indices using several scientific methods, and seven estimated indices values were shown. It is required an additional research to select the proper value among the analyzed indices.

With increasing awareness on sustainable construction and green buildings, environment-friendly construction activities have been introduced and promoted. Green value engineering (VE) is an effort that is recently introduced to facilitate environment-friendly construction. To support the application of green VE in construction, this paper suggests a green value assessment model considering the environmental performance and carbon emissions during construction. The value assessment model presented in this study is expected to help conduct objective value evaluation of construction activities in terms of both cost and environmental performance.

Task based modeling is essential in a construction operation simulation modeling. It allows dealing with local variables or delay factors that affect productivity and improves the reusability of existing operation models. An operation model can secure reality only if it reflects the real construction processes by effectively dealing with zoning issue. However, system users have some difficulties in modeling a construction operation that is consisted of several processes having different production units. Zoning is a major modeling issue when the task based modeling method is implemented using the existing discrete event simulation systems. This paper highlights the difficulty and presents a new method that complements the zoning issues attributed to different production units. The method is described in detail by presenting the flow of entities. It is confirmed that the zoning method effectively deals with the unbalance of production units between processes and facilitates to model an operation model having processes with different production units. The "Zoning module" contributes to increasing accuracy of simulation result.

The government has offered incentives to encourage private companies that are to meet the Green Building Certification Criteria. Despite offering these incentives, the Green Building Certification Criteria record share of newly-built building in 2010 is 0.35%, very low. Effectiveness of Green Building Incentive applied by the Green Building Certification Criteria is questioned. So we attempts to analysis about effectiveness of Green Building by using Cost-Benefit Analysis. But if we want to use CBA, we need to draw cost, benefit factors that compose the incentive. So in this study, for applying CBA, we analysis cost, benefit factors.

Since the financial crisis in 1997, the paradigm in property has been changed. So the domestic asset management market was generated and developed. While developing the asset management, however, there were a variety of problems about management of property information and asset management specialist shortage. For effective property management, this study propose the strategy of making information management system.

Domestic architect office from a period of high growth from the 1970s to the '80s has been established as some of the large corporations or publicly traded corporation. 1997 IMF has pointed out there is a lot of need for improvement activities in accordance with the construction recession since the 2008 global financial crisis. In order to address these causes, the company's continuous efficient operation for accurate efficiency and competitiveness analysis was required. Leverage financial ratio indicators Study Using Data Envelopment Analysis Data Envelopment Analysis (DEA) model, how to find a benchmark for the improvement of the efficiency of inefficient enterprises in various sectors being. In this study, a comparison of the conventional DEA model and the DEA-AR model is used to analyze the efficiency and domestic architect office is to improve the management efficiency.

Recently, Construction industry has been trying to reduce environmental loads reflecting the global trend 'Green Growth'. Internal and External countries are provided 'green building certification', 'relevant law/regulations', 'guideline to life cycle', however, construction phase has been overlooked though environmental loads occurred intensively in this phase. Therefore, this study intend to deduct components reflected the guideline in construction phase and assess them quantitatively. The basis data is collected through survey targeting construction managers and related researchers and analyze these data using Analytic Hierarchy Process.

Value Engineering(VE) process is going to make a series of improvements for the effective construction project management or optimal proposal to improve quality, performance improvement, cost reduction and customer satisfaction. For making the quality model based on better than the architecture that is required in the VE, such a project promoting creative plan, functionality and constructability reflecting the materials and improved construction methods and building life cycle for reviewing the smooth progress of the construction projects may be necessary for management techniques. This study is to establish a management plan in the educational facilities construction process through education institution's recent orders completed by VE case study.

The purpose of this study is to analysis of counter strategy of greenhouse gas·energy target management system for the construction firm. For this purpose, the greenhouse gas·energy target management system of other industries was investigated. The selection possibility that is construction firm to be managed company was analyzed. In addition, status of counter strategy on the greenhouse gas·energy target management system were investigated and analyzed about 5 domestic major construction firm via questionnaire and interview. As a result, the counter strategy by organization and annual for the greenhouse gas·energy target management system was drawn.

This paper presents a system architecture and database of construction quality management system which encourages real time information tracking and monitoring. It improves the real time quality record tracking by using QR code technology in the project delivery. The advantages and issues relative to QR code and the database structures of the tracking system are presented. Conventional project scheduling system, operation modeling and analysis system, and quality management system are hybridized using QR code technology. The system improves project quality management by tracking the atomic tasks which consists of a construction process at the lowest level of construction hierarchy. It analyzes the quality records to determine the causes of abnormality and/or nonconformity. Using QR code technology, the construction quality management system may be more effective than the conventional one. It was confirmed that the quality management processes in construction project delivery can be more visible and controllable by integrating QR code technology, project scheduling system, and quality management system.

Estimating the productivity of labor has relied on the experience and intuition of an estimator, or productivity data, such as standard in practical estimation. However, when new technologies and new construction methods employed in the construction industry, Dependence of a quantity surveyor's intuition is increased. This is because of the lack of a systematic methodology which models, estimates, and measures the labor productivity, Due to the historical productivity data is unavailable. Even thought project history data contains information that is important to predict the performance of a project, It can not provide valuable information to model, estimate, and measure the labor productivity. This is because 1) the absence of the productivity measurement system with consistency, 2) the difficulty of reusability of historical data collected. Therefor, this study suggests a methodology which build a productivity model by measuring the productivity of labor and collecting the historical data systematically. In addition, this methology is applied to develop a productivity model of shop-drawing and manufacturing process using descrete event simulation.

Overseas construction industry has performed the leading role in the economic development. In this study, effect of international oil prices, GDP and price index, on the regional international construction contract amount is compared and analyzed. Overseas construction market received a devastating effect due to the 1997's economic crisis. However, the market has remained stable since 1998, and since 2005, the trend has been a surge in new orders.

With the rise of BIM application and green building assessment, studies on assessment of CO₂ emissions from buildings using BIM are needed. In accordance with the requirements, this study aims at developing BIM Template database, as a part of development of CO₂ assessment technology using BIM. Based on the research of construction materials, this study develops database by applying Procurement Agency Item Code to BIM Template. The results of this research makes it possible to assess CO₂ emissions of materials with BIM Template and building data modeling implementation.

Changes in the price of materials in construction projects is one of the important variables. Therefore, measures are necessary to respond to the demand and supply of materials and price instability. In previous studies, mainly of ready-mix concrete and steel beam analysis was carried out. However, a study of non-ferrous material prices are still insufficient. So, in this study, the researcher identified the causal relationship between the construction cost and non-ferrous materials prices. Construction Cost Index was selected as a proxy variable of construction cost.

The accuracy of cost estimation at an early stage in school building project is one of the critical factors for successful completion. So many method and techniques have developed that can estimate construction cost using limited information available in the early stage. Among the techniques, Support Vector Machine(SVM) has received attention in various field due to its excellent capacity for self-learning and generalization performance. Therefore, the purpose of this study is to verify the applicability of cost prediction model based on SVM in school building project at the early stage. Data used in this study are 139 school building cost constructed from 2004 to 2007 in Gyeonggi-Do. And prediction error rate of 7.48% in support vector machine is obtained. So the results showed applicability of using SVM model for predicting construction cost of school building projects.

Recently, construction industry makes a great effort on minimizing the environmental impact. While various environmental-friendly technologies are applied to the operating phase of buildings, few equipment or machinery are partly used during the construction phase. For this reason, this study carried out a comprehensive analysis on environmental-friendly technologies for the whole construction process. In this study, appropriate environmental-friendly technologies of each construction activity were elicited to improve the environment of construction sites. Environmental-friendly technologies and construction activities were selected by professional consultation and descriptive statistics analysis, and proper environmental-friendly technologies were elicited from Cross-Impact Analysis. As a result, waste disposal and recycling technology was highly effective for demolition work while development of replacing materials was for reinforced concrete work.

Recently new construction system, the Infill Modular Construction System, is being emphasized depending on the industrialized technology introduction and the needs of high-rise housing. In order to applicate the Infill Modular Construction System and activate the domestic market, development of insufficient element technologies against the advanced technologies should be preceded and mobile device development of Infill Unit Module which is differentiated from the existing modular construction systems should be needed urgently. As advanced research for the activation of the Infill Modular Construction System, this research aims to develop Infill Unit Module's mobile device. This is expected to improve the constructability of Infill Unit Module. In addition development of mobile device considering weight of Infill Unit Module and construction errors are being planned.

A thermal stresses by heat of hydration was analyzed according to a change of a pour height in reactor containment building. In case of more than 3.6m pouring height a crack index by heat of hydration analysis resulted in less than 1 because there is not a construction joint of vertical direction and for a self-restraint effect of circumferential section shape. Therefore detailed consideration on a mixture proportion of binder type, quantity in concrete and selection of a form in seasonal air temperature is needed for a control of tensile stress by heat of hydration.

Analysis on structural effects which are reduction of friction coefficient and increase of tendon area by HDPE greased and large size strand in post-tensioning system of reactor containment building was carried out. Effective ratio of tendon force increases 67% to 83% by HDPE greased strand and vertical, horizontal internal section forces increased maximum 51%, 41% respectively. Tendon quantity could be reduced 30% by large size and HDPE greased strand that can maintain safety of ultimate internal pressure same as at present.

It is analyzed that constructability of post-tensioning system applying HDPE greased strand that is greased and coated by high density polyethylene on a bare strand in reactor containment building. The improvement of corrosion resistance by greasing and HDPE coating on a strand makes transportation, handling and installation of tendon to be easier. Therefore, serial and repetitive process of post-tensioning composed of construction preparation, tendon installation, stressing and anchoring, grease injection could be improved parallel and lumping process of installation and grouting, stressing and anchoring.

In this study the continuous rectangular spiral hoop is used for saving cost and time, solving manpower shortage, and the quality of structures. Generally the use of continuous spiral reinforcement in reinforced concrete elements improve the strength and the ductility of the concrete. Savings in cost and time is demonstrated with the continuous rectangular spiral hoop through the mock up test of beam and column elements. In case of a 4m column element the time of rebar work decreases up to 40% compared with traditional hoop, and in case of a 8m beam the time also decreases 40%. This study present the construction method and details.

Temperature during concrete curing can be effectively used to predict the early age strength of concrete However, various current methods have limits to provide the temperature data in real time due to harsh working environment including frequent cutting of wires. This paper presents the results of our investigation of an all-in-one Wireless sensor network (WSN) for the management of the curing temperature of in-placed concrete at early curing stages. Also, the network device for transmission can be easily separated from the probe sensor part and reused consistently. The field experiment entailed measuring the curing temperature of concrete using the WSN. After fresh concrete was poured into the formworks, the signals were measured at a 150 m radius from the field office. The signal was acquired for 28 days without any dispersion or interruption at the construction site; therefore, this study confirms the applicability of the proposed system to a construction site.

Korea residential housing generally use wet floor heating system 'Ondol' which consist of insulation cushioning, lightweight foamed concrete, hot water pipe and mortar on top of reinforced concrete slab. Wet floor heating system's installation process is too complicate and difficult to supervise field for continuing assurance quality. Also, this method has a huge impact on the progress of construction because it take a long time to cure finishing mortar and lightweight foamed concrete. Therefore, it is considered a disturbance factor of reduction of construction duration for enhancing competitiveness. In this study, we conducted an experiment about the radiant heat performance and temperature difference on upper panel of rolled dry floor heating systems which is jointly developed by Kolon global and Sumisho Metalex for remodeling housing, studio apartment and the urban-life housing.

The Tuned Pendulum Slab Damper(TPSD)system is mainly composed of suspended pendulum slab which was hanging with cable wire from the top floor of building without any extra loads structurally, and can be helpful to reduce vibration with effect of tuned mass damper function by the principle of pendulum movement. The experiment was performed with miniatures of the 30stories of steel structure building by the forced vibration test using shaking table, and the result was reduced about 42% of vibration. The purpose of this study was to make analysis of application of the TPSD system to new building and exist building against strong wind or seismic wave. The result of this study was that the TPSD system shall be satisfactory in field of execution, process control, safety and economical efficiency with saving up to 70% of construction cost.

Recently increasing high-rise building cleaning on the exterior walls of high-rise buildings, there has been increased interest. Building exterior cleaning is cleaned by a cleaning robot and how to clean the exterior walls of the building and exterior glass cleaned by personnel. Number of stories in the building increases, being carried out by personnel cleaning the outer wall as there is a limit order to overcome this method. therefor, this study is a new exterior wall cleaning device has been proposed.

Underground structure construction in the downtown is very difficult despite the development of construction technology. We have been a lot of research in order to solve the problem, it was a remarkable achievement. But there are still many difficulties. This study is to analyze the construction technology to demolish the existing underground structures and to build new building applied topdown method at the same time. This technology was effective to suppress interference between the exsisting structure and new building. Therefore, this technology is expected to be able to be used in similar cases in the future.

Construction work is affected by the weather; e.g. snowfall, rainfall and low-high ambient temperature, especially at a site in a severe climate. The influence of the weather is one of the possible reasons for delays in a construction schedule and quality deterioration. To protect the worksite from severe weather conditions, the temporary roof and wall could be installed on the outside of main structures designed in advance and the temporary structures could be took down after a period use. The greater coverage all-weather construction method is applied, the larger the effect. so, it is important and needs that the temporary roof and wall can be widely applied, designed to effectively about structure and layout.

Because of the high level of the safety and durability, a lot of reinforcing bars is placed in the concrete structure of the Nuclear Power Plant. But the overcrowding re-bars cause some problems during the construction as the diseconomy, construction delay, quality deterioration, and so on. These problems can be solved by applying the high-strength reinforcing bars to NPP structure. To achieve this, after analysing the structural target performance like the control of cracks, adherence, shear, torsion, development of reinforcement and earthquake-resistance, the results of the analysis will be reflected in the structural performance evaluation test.

If the mechanical development be applied to the Nuclear Power Plant Structures instead of the standard hook development, the problem of overcrowding re-bars in the anchorage zone can be solved and the construction quality of the concrete work will be improved. But there are some problems in applying it to the NPP structures because of the restriction on the re-bar yield strength and diameter. After the performance evaluation test for the mechanical development, we can develop the new design equation of the mechanical development length in order to solve the limitation and apply it to NPP structures.

Recently, High-Strength steel reinforcement has been studied throughout the internal and external. One of the advantages using High-Strength steel reinforcement in construction is the economic effect due to the decreasing of its quantity. Also, another good effect is the increases of workability by reason of reducing the congestion. But, realistically it is not used in nuclear power plant construction site because of the restriction of design standard. The purpose of this report secures the reliability and changes the code through the performance evaluation test of the wall using the high-strength steel reinforcement in nuclear power plant.

One of the advantages using High-Strength steel reinforcement in construction is the economic effect due to the decreasing of its quantity. Also, another good effect is the increases of workability by reason of reducing the congestion. This study explain plan of experiment after analysing of ACI 318, 349, 359 to develop 550MPa re-bar design criteria applicable to flexural members of nuclear power plants.

In general, nuclear power plant concrete structure's performance has been very good with the majority of identified problems initiating during construction and corrected at that time. This study is experiments to improve drying shrinkage using glycol ether-based material for the durability of nuclear power plants. Thus, this study evaluated the obtained data from a mock up test for the practical use of concrete containing glycol ether. According to the results of this study, the concrete showed resistance performance of around 40% to drying shrinkage.

This study is aimed to utilize for basic material of concrete quality management through evaluate properties of fresh and hardened concrete with the aggregate quality. As a result, fine aggregate's slump change of between one grade was 8~82% and in case of coarse aggregate, slump change of between one grade was 2~22% on same mixing condition. The unit water for same workability condition, unit water was increased 16kg/㎥ with decreasing of one grade for fine aggregate and unit water was increased 5kg/㎥ with decreasing of one grade for coarse aggregate.

Cement is an essential material for social infrastructure. Cement production process for cement itself is energy-intensive and requires a large amount of natural resources for fuel and raw materials. This study is to development of recycled cement from waste concrete powder in manufacturing process of recycled aggregate concrete. Recycled cement is low carbon and green growth materials concept for eco friendly construction environment. From the test results, waste concrete powder is same chemical proportion regardless of manufacturing process of recycled aggregate concrete.

To prevent energy waste in buildings used heat insulator. Heat insulator materials can be classified inorganic and organic. The organic material is due to toxic gas emission, when a fire occurs. And it 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 fire resistance performance of the curtain walls. This study focused on evaluation of the physical properties of light-weight inorganic foam panel for using industrial by-products materials and performance evaluation by mock up test.

This study is about the assessment of utilization possibility as a material for cementation of ground which is necessary for the reinforcement of soft ground by making environment-friendly inorganic composite utilizing inorganic recycled resources, and it was verified that it showed higher uniaxial compressive strength than the existing cementitious ground solidifier when it was applied as a combination material for soft ground such as dredge reclaimed land, and since an inorganic composite utilizing recycled resources such as high calcium fly ash and blast furnace slag etc. does never use cement, it is considered that it would be safe in the issue of a hexavalent chromium that was recognized as a problem of a cementitious solidifier.

The purpose of this study is to analyze the situation and feature of construction technology by analysis properties and the mixture proportion of a reinforced concrete building from the modern domestic and to leave technological records for the optimal maintenance of the cultural heritage. The study says, the case of the 1:3:6 mix concrete has been standard regardless of the kind of structures after the concrete has being used in earnest, However, The strength range is big from Water-Cement ratio difference according to the concrete casting site.

In this study, the experiment was conducted in the level of mortar as one of the basic studies on pre-cast concrete which acceleration curing is not done. This study has the purpose to develop the strength of mortar into 20MPa within 6 hours in the condition of room temperature using admixtures which can accelerate C3S hydration reaction. In this experiment, W/C was fixed into 20%, PCE which can stimulate C3S was used as an accelerating admixture. From the results of this experiment, maximum content of accelerating admixture was 1%. Also, as more than 20MPa was measured through 6-hour compressive strength, it can be known that strength can be developed without steam-curing.

This study is to high early concrete development which reveals 14 MPa within 12 hours in order to reduce the mold time of dismantlement and not do the steam curing of the precast concrete product. About (40~50) min could shorten the final setting time if the coagulation test result cement amount 100 kg/m3 was increased. In the case of the compressive strength, it was exposed to be satisfied the target value with the cement amount 500 kg/m3 combination according to the hardening accelerator addition.

Nowadays the widely used media in architecture include visualizations, animations and three-dimensional models. An optimized 3D digital method using active CAM(Computer Aided Manufacturing) and CNC(Computerized Numerical Control) imaging is developed for accurate shape and 3D measurements in freeform buildings in this paper. In contrast to a conventional building using auto CAD system and others, the proposed active digital optimization is based on a combination of 3D numerical data and parametric 3D model. The objective of this paper is therefore to present digital optimization method for constructability of freeform building. The 3D digital optimization method is appropriate to serious variations in freeform shape. The developed digital optimization method is necessary to be carried out to verify the robustness and accuracy for constructability.

In contemporary architectural practice, flat sections and plan drawings are no longer a primary means of representation and communication with participants. A typical building design has an ornamental exterior wall system and a roof system that should have water-proof quality and drainage function. By comparison, distinction between exterior wall and roof are unclear in freeform buildings, and they are integrated into a concept of a building envelope. This study is to propose 3D coordinate control technology for freeform structure by CNC curved tube method in order to develop a BIM-based envelope design and construction method for freeform building. Because a much wider freeform building construction can be achieved with correct 3D data and easy-to-implement in construction field, the proposed 3D coordinate control technology is highly recommended for practical use instead of the conventional CAD system.

The supply chain in plant construction project can be defined as a network combined between elements which is engineering, procurement, construction, start-up. For successfully leading construction project, close relation and mutual cooperation should be preceded and Supply Chain Management(SCM) system is needed to improve the relation. In particular, because safety is a top priority for the companies work in the construction of Nuclear Power Plant(NPP), it is necessary to control all parties realated with NPP construction systematically. In this situation, it is important to purchase high-quality equipment in timely manner by developing Integrated cooperative systems. Therefore, this study aimed to propose developing solutions of SCM such as JIT and Envelop Design system, which can reduces difficulties of decision making between the parties involved in the project and will increase the efficiency of the engineering process in NPP.

Continually having growed up overseas construction market for new Nuclear Power Plant(NPP), the exports of Korean Reactor emerges as the key task of National Nuclear Business. The objective of this study is to strengthen the competitiveness of Korean Reactor through the improvement of Construction Project Contract & Delivery System for NPP. This study suggests the method for increasing Korean Reactor's competitiveness of exports by analyzing the business environment of foreign market and comparing Contract & Delivery System between domestic and foreign.

As a way to improve productivity and integrated project delivery in construction industry, BIM(building Information Modeling) using IT technique is being studied and applied recently. S-BIM application Process was established that enable efficient work through Structural BIM detailed Model in consideration of the collaboration among relevant fields. This study has the objective applying S-BIM technique to enable effective Cost Analysis in initial design phase and presenting the method for practical works using Construction Cost Analysis Process based on S-BIM.

The major industrialized nations have continued to develop industrialized construction techniques based on automated production processes in factories, and are applying them to a wide range of building. However, the unit modular construction system has had a shorter history of development and application in Korea compared to advanced countries, and consequently, Korean modular builders have a relatively poor technical capacity. So this study is draw a conclusion on the target of priority improvement for idea creation. It study on the enhancement of the functionality of the tool for assemble of Unit Modular that choose the enhancement of the functionality through the analysis of function on the three-level of functional definition and classification, functional arrangement, functional appraisal.

Recently, research has been actively conducted for getting interested in unit module housing. However, the domestic unit modular housing research in the early stages yet, so the major process for research is lacking. Explore all these reasons fit with domestic unit housing development this paper, focusing on the process of shipping cargo by truck, transport unit module was studied. The purpose of this paper is to present new ideas and derive the direction of the development of the equipment safely and effectively fixed to the unit module of the transport unit module that will be helpful in the development of the equipment required for the transport process of the next unit module.

Lately the Infill Modular Construction System which meets the domestic standards about the structure and fireproof performance and which is applied to the remodeling techniques is being emphasized. In order to introduce the Infill Modular Construction System to domestic market successfully, the development of insufficient element technologies and systematic analysis of process should be preceded. This research aims to establish of Standard Construction Process, as advanced research for the settlement of the Infill Modular Construction System. As advanced research for the activation of the Infill Modular Construction System, this research aims to develop Infill Unit Module's mobile device. This is expected to improve work efficiency. In addition organizing optimized Standard Construction Process by steady work analysis and improvement is being planned.

Concrete based on blast-furnace slag has a problem that its deterioration occurs process and quality of concrete are difficult to control. Therefore, it is judged that organized and comprehensive R&D will be continuously performed. In this study, the durability of concrete replaced with blast-furnace slag was evaluated for a solution. Experimental results, Concrete based on blast-furnace slag improved the durability.

The purpose of this study is to suggest and verify high-strength concrete mix design model applying neural network theory, in order to minimize effort and time wasted by using trial and error method utill now. There are 7 input and 2 output to predict mix design. 40 data of mix design were learned with back-propagation algorithm. Then they are repeatedly learned back-propagation in neural network theory. Also, to verify predicted model, we analyzed and compared value predicted from 60MPa mix design with value measured by actual compressive strength test.

Epoxy resin without any hardener can harden in the presence of hydroxide ions in cement mortars and concretes at ambient temperature. The purpose of present study is to examine the hardening properties of hardener-free epoxy-modified mortars by curing conditions. The hardener-free epoxy-modified mortars using diglycidyl ether of A epoxy resin are prepared with various polymer-cement ratios, and subjected to initial moist/dry curing, initial steam(90℃) curing, initial steam/heat(80℃, 100℃) curing.As a result, degree of hardening of epoxy resin in initial moist/dry cured, initial steam cured and initial steam/heat(80℃) cured hardener-free epoxy-modified mortars is decreased with increasing polymer-cement ratio. However, it is markedly improved with additional dry-curing periods. On the other hand, regardless of the polymer-cement ratio and dry curing periods, degree of hardening of hardener-free epoxy-modified mortars with initial steam/heat(100℃) cure is over 95%.

As RC structures in the marine environment rapidly increase, the interest and the importance of Chloride Penetration durable design have been growing. However, there is hardly any domestic Chloride Penetration durability of RC structures designed analysis programs. Currently, Chloride Penetration durable design method is studied and launched actively as a program in the United States, Europe, Japan and etc., but it is limited to Chloride Penetration durability of RC structures excluded from maintenance construction. Also, the level of dependence on the foreign technology is high; the foreign program is imported and used when needed. The main objective is to compare and to evaluate with the durability assessment program and several conditions when considering the design of Chloride Penetration durability through the programs developed abroad.

The field application through the quality control of self adhesive rubberized asphalt waterproofing sheet was regulated by KS F 4934 of Korea Standard in 2003. However, regulations that different material properties of self-Adhesive waterproofing sheets are difficult on the standard. Therefore, this research was performed for of quality control all affiliations of self-adhesive waterproofing sheet through basic properties test and proposed quality standard revised bill in KS F 4934.

In this study, the ultra high strength concrete which have 100, 150, 200MPa took the heat from 20℃ to 70 0℃ 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.

The purpose of this study was to investigate the compressive strength property into mortar using rice straw ash. In an effort to evaluate the effects of rice straw ash firing temperatures on compressive strength properties of mortar, a change in the components of rice straw ash was observed according to firing temperatures, and compressive strength of mortar and X.R.F was measured. As a results, As the mortar with a mixture ratio of rice straw ash up to 15% was found to have a compressive strength superior to that of plain mortar.

To evaluate the incoming salt quantitatively which is the reason of salt attack is a very important aspect to calculate the durability life of the structure. Incoming salt is influenced by various weather changes during the transmission and consequently, the changes of incoming salt quantity occur. Therefore, the study to analyze incoming salt quantity was executed which are changed by the weather environments (occurrence frequency of wind direction / wind speed); study results showed that influences to the changes of incoming salt quantity are bigger than those of wind speed, compared with the frequencies.

In this study, for purpose of having a prediction on the flowability of mortar, we use the theory of excess paste, which gives a relationship between viscosity of paste versus water-binder ratio and mortar flow versus relative excess paste volume. Pastes and Mortars with four different mix proportions incorporating mineral admixtures were prepared. As a result of experiment, it seems that high flowability of mortar can be attributed to both lower viscosity of paste and increasing the volume of excess paste.

In apartment building with column structure, reinforcing bar of the column is constructed mainly using gas pressure welding job. Therefore, gas pressure welding job in very critical process is construction apartment building with column structure. The purpose of this study is to analyze productivity of gas pressure welding work in column structure apartment using Web-CYCLONE. In this study, a CYCLONE model was developed for the productivity analysis of gas pressure welding work. Through this model, the optimal combination of the resources was obtained. This study will be utilized in the future as a useful tool of productivity analysis and the determination of an optimal combination of resources for gas pressure welding in apartment with column structure.

After the introduction of CM(construction management) for improving productability in construction industry, the CM market was shown to actively grow shape until 2007 but suddenly appears passive movement of the market after in 2008. However, on one hand, the CM corporations has increased, because the construction supervision market come to the CM market area by reduction their work place. Because of this, it was discussed that will intensify competition between companies in the CM market. Therefore, this paper want to analyze to status of the CM market structure for studying about the CM industry status and change during last 3 years. As a result, by decreasing the Market concentration, the CM market competition rate did not too high with business despite that CM market downsize and has been increased the number of companies.

The Construction Standard Production Unit(CSPU) has been used for the standard cost estimate in public and private construction projects. However, It is questionable if the reliability and/or authenticity of the system is acceptable due to the lack of consistent enactment and/or revision procedures. This study identifies informational conditions and issues relative to using daily work report as a data collection method for enacting and/or revising CSPU system, and establishes the measures for improving the daily work report. This study aims on the information constitution of daily job-site report, daily manpower report, wages register for specialty contractors. According to the research results, most of necessary data were included in a daily job-site report. In conclusion, it is investigated that data of daily manpower report and wage register need to be included in a daily job-site report for understanding the current state of worker in the future.

Construction performance and productivity improvement are key focus areas in construction industry for any nation. There have been frequent delays and cost overruns in construction projects and poor productivity is one of the major contributions. For this reasons, there have been many research studies performed on the improvement of construction productivity for several decades. However, measuring productivity on a construction job site is still not an easy work. Because collecting reliable data consistently from the job site requires a lot of personnel efforts causing extra time and cost. This paper provides a basic study on the application of image processing technology for measuring unit productivity. It presented the possibility of unit productivity measurement by image processing technology through case study.

High-rise building construction has been increasing for the recent years and the construction process has become more complicated. This suggests a need for precise planning based on reliable data to prevent cost overruns and delays. However, the process planning is implemented based mainly on the experience of engineers that can result in critical damage in cost and time. Accurate productivity estimation and unit cost analysis must be considered important matter to prevent such disaster. This study estimates productivity and unit cost of curtain wall operations in high-rise building construction by simulation techniques and statistical methodologies. This study suggests a decision making methodology for the site personnel that enables to compare various combinations of productivity and unit cost based on reliable data that has been collected in actual construction sites. It is expected that this study contributes to the following research of developing an optimized construction performance assembling model for the site personnel.

In the large scale projects, it is difficult to manage every blocks because of the apartment housing project have repetitive shapes and structures. Therefore, it is necessary to divide construction site into work zones and blocks considering site plan, the number of units per each floor, arrangement of blocks, etc. In this study, 20 influencing factors on the grouping of work zones and formwork crew team formation are identified through case study and literature review. Factors are analyzed to determine the degree of influence through experts interviews. A systematic process of crew formation based on work zoning and the considerations by each steps are presented.

The building construction industry of Korea was going through difficulties in improving productivity and competitiveness in international market. Therefore we expected to see the improvement in productivity by applying six-sigma based approach to general reinforced concrete construction work. As a result of applying DMAIC method, one of 6 sigma tools, we found that the most effective inspection items are 'Gap of forms' and 'status of clean'. We could see from this case study that the percentage of additional work days has decreased to 37.7% as a result of applying six-sigma based approach to reinforced concrete construction.

Progress in the construction project, the estimated cost of the measure is very important. Use preliminary estimate cost data for the prediction of construction cost. But, preliminary estimate cost data a clear calculation, there is no way. it is rely on the historical data and the past construction data. As a result, a significant difference in the actual construction cost and the predicted cost of the problem occurs. In this study, taking advantage of BIM Cost Prediction for efficient and rapid preliminary estimate BIM for building database through the study preliminary estimate cost data.