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This paper introduces a system called Simulation-based Stochastic Bidding Cost Estimation System (S2BC) that use simulation modeling and analysis technique. It better represents the real world system involved in construction bidding. The prediction accuracy was compromised because of the assumptions which existing models have adopted. However, The S2BC complements the lack of accuracy. Historical bidding data obtained from the Korea National Housing Corporation was used to validate the method. Bidding projects in the Historical DB were selected by random sampling. The ration of bidding let was calculated using the occurrence of participants who entered into a specific bidding. On the assumption that bidding pattern retained on the historical DB has reproducibility, the probability of winning was computed using the cumulative probability distribution that is obtained from the user defined numbe r of random sampling of bidding projects out of the Historical DB. The existing computation, which is handled by means of deterministic procedure, was converted into stochastic model using simulation modeling and analysis technique. The best fitted probability distribution function is estimated using the historical data. The reliability of estimating probability of winning on specified bidding let is improved using the S2BC.

The object of construction project management is to achieve planned quality by adequate cost and schedule of the project, thus the effective time management is a critical factor to actualize the object. But the traditional time management by using milestone has several limitations which are not sufficiently considered mutual relation and variated from the task. In other words, applying the concept and principles of Lean Construction to the project shall be the best way to not only reduce waste and variation, but also improve the productivity and ability to overcome limitation as mentioned above. Thus, this study proposes specific and systematic time management through introduction of management method of lean construction. The study, Last Planner System, specially focuses on constraint analysis which is used in Lookahead planning system. Consequently, this study presents constraint analysis able to improve reliability of work and Percent Plan Complete by controlling major factors of project before the planning phase.

It is seen the construction project which comes to be constructed recently. It gradually is a tendency which becomes highly, largely and complicatedly. The important gradually increase the hoisting, specially case of skyscraper construction of the city center area from smallness one space to ascend with the upper floors it is gradually augmented. It develops the automatic hoisting technology of the tower crane which uses a radio frequency identification from in automation technique. Like this research to lead the work efficiency of the tower crane and safety of worker come to be high.

Ministry of construction and transportation has been enforcing extensionally design phase VE(Value Engineering) to the construction costing more than 10 billion won, an importance of design phase VE accordingly is raising to get rid of a waste of cost and noneffective factors previously in construction projects. Although there are legal supports and technical effects, an effect about an introduction of design phase VE can not be applied properly because of several problems at the process. So, in this study, present competency evaluation checklist of design phase VE to highly raise the output through organizing an effective team at the beginning stage of design phase VE. Find out 29 competency factors through characteristics of design VE team for the checklist, classify by team knowledge, team work skill, and team attitude. Get an efficiency regarding importance and find out competency evaluation items of design VE team, present a competency evaluation checklist for indicating an objective standard to competency evaluation by measuring relative importance as to each competency evaluation item.

Quality cost is used as a main rating indicator which measures evaluates validity and efficiency of quality system. Quality cost even takes up over 10~20% of overall construction cost, which shows the impact and significance on business and competitiveness of the industry. These days, among domestic construction industry, centering around major companies, the implement of quality cost system is promoting as a solution for evaluating validity and efficiency of quality system. This study structured presented quality cost item's classification system reflecting characteristics of construction works to utilize as the standard of measure evaluate quality cost for solving these problems. Evaluations were performed focusing the users, after measuring and analyzing construction works' quality cost to verify validity and efficiency of classification system of construction works' quality cost item. As the result show, measuring and analyzing quality cost, applying to established quality management system, were concluded to be easy, based on the fact of having excellent capability among all the value factors, particularly the compatability with quality management system was excelling.

In this study, it has been indicated reasonable investment decision makings for an apartment house remodeling and the process to analyze VE/LCC(Value Engineering/Life Cycle cost) analysis for selecting patterns. Through the process indicated, it makes the squandering of resources and environmental disruption minimize in public. In the ultimate, this research is accomplished to indicate objective analysis patterns for the value which is a main valuation pattern for the most reasonable investment decision makings. The VE/LCC process is applied to remodeling selecting patterns in real as well.

In this study, it was investigated the state of domestic and foreign demolition engineers for the development of the domestic demolition industry. And it was analyzed the market size and company state in the domestic and foreign demolition industry. We suggested six proposals, such as trainning of demolition engineer, D/B establishment of expert, opening of teaching program, arrangement of teaching system, accomplishment of institution, to devolop the domolition industry.

This research examines basic property of sub-slab concrete mixed with recycled coarse aggregate, according to different unit quantity, replacement ratio of fine and coarse aggregate, BFS, and FA; the purpose is to encourage use of recycled aggregate. In case of fresh concrete, the fluidity increased along with the replacement ratio for recycled coarse aggregate; the air volume became larger in mixed concrete than in plain as the replacement ratio for recycled coarse aggregate increased. Mass for unit volume declined with the increasing replacement ratio. As for hardened concrete, compressive and tensile strength of mixed concrete reached over 80% of plain concrete, up to the replacement ratio of 30%. For drying shrinkage, the change in length became greater for mixed concrete than for plain as the replacement ratio increased.

The purpose of this study is to suggest approaches to cost-effective decision-making through cost-benefit analysis tools for evaluating various alternatives in architectural planning and construction. For this study, we applied tools of life cycle cost, economic value added, return on investment for a cost-benefit analysis framework.

Recently advanced nations utilize evaluation system about LCC, and KOREA begin to introduce the system to reduce construction expense. And Introducing "Technical proposal type bid" that is new government construction order mode made needs for valuation of price to evaluate facilities LCC. These days LCC is evaluated by BTL and turnkey project in KOREA, but it is suffering from difficulty in evaluation. because evaluation element and standard are indefinite. In addition LCC evaluation of public construction business except BTL and turnkey is not consisting. Therefore, in this research we present LCC evaluation Index for systematic and objective evaluation.

In current, the building construction has been mega-structured and more complicated, so it is strongly demanded for reducing the working duration. In order to accomplish this, it should be systematically planned for the working schedule of workers, building materials, and construction equipments. In the aspect of managing workers, building materials, and construction equipments, however, the deviation of the workers' attendance is large and the rate of working time is not continuous but intermittent. The purpose of this study is to establish the materials management system for the concentrated management of multi-construction sites in the aspect of Multi-Construction Sites. - Development of building materials, and construction equipments in multi-construction sites.

Recycled aggregate that is waste tile and waste interlocking block result, waste tile and waste interlocking block that execute an experiment to foretell practical use possibility availability as recycled aggregate for concrete giving change in the principal parts rate for coarse aggregate recycled aggregate appeared in the world by available thing to coarse aggregate to rate 10% but necessity that present amount used establishing material application standard that is crushed than uniform application standard to receive entropy of recycled concrete quality is judged to be.

This study investigated the application of lightweight foamed concrete due to change of unit volume weight and W/B. The result of the examinations about change of unit volume weight and W/B on the lightweight foamed concrete mixed various powdered material showed that unit volume weight and W/B which were favorable to applicate were 0.5-W/B 70%, 0.6-W/B 65%, and 0.7-W/B 60%. Sinking depth decreased according to increasing unit volume weight and W/B, but air void content increased caused by decline of unit volume weight. All proportioning without each unit volume weights on W/B 70% satisfied KS range, and heat conduction of all cases also satisfied KS range. Totally, compatibility conditions according to change of unit volume weight and W/B to applicate were estimated as 0.5-W/B 65%, 0.6-W/B 60%, and 0.7-W/B 60%.

This study investigated the fire resistance properties of high strength concrete due to the various mixing ratios of nylon and PP fibers. Ahead, on the fresh concrete, All of the changing fiber contents satisfied 700±100mm on slump flow and 3.0±1.0% on air content. The compressive strength of all were about 70MPa, and tensile strength was about 9% of the compressive strength. However, there was not definite tendency due to change of fiber content. On the spalling properties after fire test, spalling and scaling occurrence on below 0.03% of fiber content, and spalling was prevented on above 0.04% of fiber content. The residual compressive strength was above 30% on more 0.03% of fiber content. Especially, it was about 59% in the case that nylon and PP fiber was used concurrently on 0.05% of fiber content. Totally, the spalling was prevented on 0.04% of fiber content, but 0.05% of fiber content was the best condition considering safety and economic.

Waste concrete has been increased by an acceleration of the development of urban and the enlargement of redevelopment projects, so recycling of waste concrete is actively progressed. However the usage is limited to a lower value-add such as the roadbed material etc. Now, the research and the development have been performed to produce the high quality recycled aggregate. However recycled fine aggregate has low quality because it contains large amount of old mortar. Thus to produce the high quality recycled aggregate, breaking and washing process must be added to the existing process and the ingredient of old mortar must be removed from aggregate. Also, alkaline water which occur from treatment process of the waste concrete is becoming the cause of environmental problem. Accordingly, this research is to develop on the high quality recycled fine aggregate produced by low speed wet abraser using sulfur and investigated the engineering properties of the mortar used the recycled fine aggregate by this process. Test results indicate that recycled fine aggregate by acid treatment process satisfies the quality standards of KS F 2573 (recycled fine aggregate for concrete) for the first-grade recycled fine aggregate. It is also shown that strength of mortar using recycled fine aggregate by this process was great to that using recycled fine aggregate removed under 0.15mm powder by sieving.

This study investigates spalling properties of high performance concrete, W/B 25%, made with maximum sized coarse aggregate and lightweight aggregate, adding ratio of polypropylene(PP) fiber. Test results showed that increase of the fiber content but decrease of the maximum sized aggregate inclined the fluidity of fresh concrete. Especially, fluidity was inclined in the case that the maximum size of aggregate was 25mm. For the properties of harden concrete, the compressive and tensile strength due to increase of PP fiber content is similar tendency. The result showed that the spalling is prevented When the ratio of PP fiber was 0.10% on 20mm of the aggregate size, and residual compressive strength on 0.15% of PP fiber content was opposite tendency to the aggregate size. There was no spalling without the fiber caused by the inner pore of aggregate in the case that lightweight aggregate was 4～6mm.

Salt injury and carbonation which is the a blazing primary factor decreasing durability of concrete is fatally based on prior performance lowering of concrete structure, structure stability, and reduction of serviceability limit period. Especially, in the event that chloride is penetrated and spreaded to reinforced concrete structure, salt injury becomes primary factor lowering of durability performance such as crack and popout of concrete due to iron expansion. In this study, after durability improvement agent which strengthens carbonation and salt damage resistance is added to concrete as much as 0.0, 0.3, and 1.0% , engineering properties such as slump flow, air content, and setting time & durability such as compressive strength, cracking state, and chlorine diffusion factor in the watertight concrete are measured. As a result, although durability improvement agent is not effect on engineering properties, it is make sure that durability improvement agent is effective to improve durability because of reduction of carbonation, cracking and diffusion factor of chloride

This research intends to offer bases on the thesis of earth construction technology through the analysis of the case of brickworks and plastering works in city of Gumi, Kyeongsangbukdo. We search for those instances of earth buildings because we need to follow trends that earth construction recognize as environment-friendly, sustainable and newly spotlight field to alternatives of building construction techniques. This research follows those orders; we study theoretically and then make a frame of analysis through theoretical consideration about earth construction and prior study. Finally, we analyze the selected buildings which is selected by priority in city of Gumi as authorized preservation value, cultural assets and recently built modern constructions. We lead to draw the conclusions about the problem solution and the invisible development of technologies of earth construction method in the case study which those buildings have as we study.

Currently the domestic apartment house from the situation which attempts a development with the quality side of the materials market and currently our interior finish materials tendency is follow as elegant, diversification, differentiation day by day according to globalization. The research which it sees recognizes importance of interior finish materials in apartment house so it grasps especially with the space finish materials preference of the consumer investigates and comparison that it analyzes is objective of this research, and finality it presents the fundamental data of the overview and system of finish materials totally which it does organization in selection of the consumer with dwelling plans.

Recently skyscrapers with high-strength concrete come to the spotlight internationally and main downtown buildings in the world get ultra higher-storied. However, Korea avoids using high-strength concrete because of the reasons as a lack of its construction experience and study. Therefore, the purpose of the study was to make a close inquiry into each kind of engineering properties with high-strength concrete of 80MPa and to select the optimum combination of high-strength concrete with good applicability and placeability. The study set up its condition of testing combination as W/B(25%), S/a(45%) and W(160㎏/㎥) and enforced experiments, mixing and adding each kind of binders in many ways. Also, the study used the minimal quantity of superplasticizer with in a scope to satisfy slumpflow of its target. As the result, combination of type Ⅱ showed good results in flowability, strength properties and durability.

The purpose of this study is carbonation control of concrete by the ratio of Steel powder. First, The depth of carbonation and penetration depth profile of chloride ions in admixture mortar was decreased greatly by increase the displacement ratio of Steel powder and changing the property as compared with non-admixture mortar. Accelerated curing of corrosion after accelerated carbonation test is also performed to accelerate the corrosion of steel powder. The depth of carbonation correlates the pore volume and pore size distribution depend on exposure duration in the accelerated chamber. The penetration depth of mass in different environment of corrosion decreases due to the replenishment of pore by corrosion products. Based on these test results, concentration depth profile and diffusion coefficient for chloride ions of mortar that mixed with steel powder was decreased 20%～80%, compared with plain mortar.

This study investigates the evaluation of concrete due to the solid powder and leaving along time recycling water containing saccharic based stabilizing. Test results showed that increase of saccharic based stabilizing agent(SSA) inclined the fluidity of fresh concrete and declined the values with leaving along time progressive as well as indicating the similar tendency in terms of air content. For the setting time, while specimens using only recycling water without SSA were not dramatically different from that of control concrete and it was accelerated according to prolonging leave alone time and increasing solid powder, it is confirmed that specimens using more SSA effectively delayed the initial and final setting time. It was demonstrated that the compressive strength of concrete using SSA slightly and the content of solid powder increased, but it was decreased that leaving alone time was prolonged. Lately, It was also demonstrated that the length change by drying shrinkage was increased caused by prolonging leave alone time and increasing solid powder, but it was decreased according to more SSA.

Currently buildings in Korea get ultra higher-storied by rapidly changed technology of construction and a dense population. However, Korea uses high-price silica fume depending on import in the whole quantity generally to be manifested compressive strength for ultra high-rising buildings and currently has a lot of difficulties in applying high-strength concrete to the field by increase of concrete’s unit price according to using silica fume. Therefore, the study enforced experiments, setting up each kind of water-binder rates and fin aggregate rates to achieve design standard strength and slumpflow of its target and applying each king of additives to analyze engineering properties of high-strength concrete with high-strength binder with which we can replace silica fume. As the result, high-strength binder showed better tendency than the existing silica fume in fluidity and early strength properties.

This study investigates the chemical reaction of the aluminum with alkali and others of the concrete as the fundamental research for the development to improve finishability of the concrete using the aluminum form. As the results of the observation, the reaction is increased in accordance with Ca(OH)2, KOH, NaOH, and NH3OH. For the KOH and NaOH, extreme reaction is occurred even 0.1m, and the damage for the aluminum is advanced rapidly. For the amount of the hydrogen occurrence according to changing temperature on 0.1m, it is increased in accordance with growing temperature, however it is suddenly declined at 5℃. The amount of the hydrogen occurrence increases gradually by increasing W/C of the cement paste. It is caused by reacting time between the aluminum and hydroxide of the cement and moving time of the hydrogen gas delayed on the cement paste at low W/C.

This study investigated the effect of the mixture of the mechanical properties of the lightweight foamed concrete. The lightweight foamed concrete was fabricated to provide the method for the fire resistance and spalling prevention of the high performance concrete(HPC) attached with the stone panel. For the fluidity according to the mixing factors, it was increased with the increase of W/B. The target flow was achieved based on mixture adjustment regardless of W/B except for OPC 50 mixture. The sinking depth is within the range of KS, and the amount of foam showed similar tendency with the amount of foam. The apparent densities of the OPC 50 and OCL 50 also satisfied KS. Although OCL use less cement for the OPC, OCL 50 was most favorable at 7 and 28 days caused by the micro filler effect of the CKD and LSP. The thermal conductivity of all specimens were satisfied with KS. In conclusion, it is believed that OCL 45(unit volume weight : 450kg/㎥, W/B : 60～65%) was most appropriate for the packing materials for the fire resistance and spalling prevention.

This research intends to understand the rammed earth method and suggest the possibilities of adoption on high-rise rammed earth structures through the case study on the method. The rammed earth construction has been regarded as one of the solutions in the modern environmental-friendly construction field, thus according to such trend, this study tries to find out the limitations of the rammed earth structures to be multistory and grope for solutions in the attached wall construction method. The procedures of this research is to figure out the limitations of rammed earth structures through theoretical consideration on those structures and analyze the actual cases of them, and to assure the possibilities on the development of the rammed earth method that can make the structures multistory earthen structures in the rammed earth method and induce immediate issues for it.

The citizen of world is getting interested in circumstance therefore respective country struggle that eco-friendly environment has to be saved. A form of pert of the this certification, which is a Green Building Certification System, a Korean government has worked to certification into confirmation institute and reform the raw. In this study, we are going to compare with foreign certificated system which are LEED, CASBEE, GB-Tool2005. And then we would like to fix on our certificated system. The citizen of world is getting interested in circumstance therefore respective country struggle that eco-friendly environment has to be saved. A form of pert of the this certification, which is a Green Building Certification System, a Korean government has worked to certification into confirmation institute and reform the raw. In this study, we are going to compare with foreign certificated system which are LEED, CASBEE, GB-Tool2005. And then we would like to fix on our certificated system.

In case of occurrence of sunshine disputes over educational facilities, values which come from the analyses make differences according to sunshine measuring standards against classrooms and playgrounds and also the values continually have the points at issue. The results of this study were as follows; specialists say that each centerpiece of opening per classroom is the most valid as standards which people estimate sunshine environments, the method to allot the measuring point by sector standard is adequate because it is regular and consistent. it is found that standards for establishing sunshine limit values that consider sunshine environments of four seasons or the whole year is necessary.

This study aims at constructing EGIS DB of a coastal area Haeundae and performing statistical analysis for understanding urban structure and for ultimately accomplishing numerical simulation. The accomplished results of this study are as follows. 1)Building Information Database is constructed as integrating digital maps and building register file into an GIS Database. 2)EGIS DB is constructed as mesh data with environmental information data and preceding building information database. 3)EGIS DB is converted into statistical data supporting to accomplish statistical analysis and calculate urban structure factors' figures according to frequency analysis . 4) On the base of 18 urban planning items of study area, 6 component is pulled out according to Principal Com ponent Analysis and whole study area is grouped as 8 types. 5) To evaluate thermal environment of 8-type group, summer thermal environment simulation is carried out by UCSS (Urban Climate Simulation System) Box Model and the result is analysed on the side of air temperature and heat budget.

In the current residential building, hot water supply system consumes the second largest energy in order to make the thermal comport condition of residential space. The more residential environment improves the more the demand for hot water and water consumption is increasing gradually. So this study examines the possibility of applying the recirculation for individual hot water supply system compared with the existing method for waiting time for hot water, wasted water and energy consumption. The results are as follows. (1) In case of recirculation system method the waiting time for hot water can be reduced up to 69～85% in spring and fall period and so dose up to 77～85% in winter period. (2) The total wasted water has a little change compared with the existing method which can make the total wasted water reduced about 77～86%. (3) The efficiency of hot water supply system can be improved, if the method which blocks the inflow of cold water is applied, when return pump is operated to recirculate hot water in recirculation system.