Earticle

Spatial structures have the different dynamic characteristics from general rahmen structures. But, because most researches of vibration control were conducted for rahmen structures, the usable results of those researches are very limited for vibration control of spatial structures. This studies is conducted about the arch structures that the basic dynamic characteristics of spatial structures is inherent in, and the change of its seismic response is analyzed according to installation location of TMD(Tuned Mass Damper). The seismic response of arch structure is effectively reduced, when TMD is installed on a quarter of its arc length.

According as the demand of high-rise building has been increased lately, the using of high-strength steel has been also increased. Many studies on high-strength steels have performed such necessity, but in case of hollow section, the design equations limit the maximum yield stress up to 360MPa in the design code KBC 2009. So it is necessary that the study on the 600 MPa circular hollow section(CHS) with various type of connection is required. An experiment study on the longitudinal plate connection has already been carried out. This study is performed to investigate the behavior and strength of tube-gusset connection through comparing the experiment results and FEA. The maximum strength can be expected by FEA with less than 8% error.

This paper presents an analyse study on structural performances of the high-strength steel material with low yield ratios, which has been developed recently by modern steel-making technology in Japan(so called, 60kg class high performance steel). The purpose of this study was to analyze the structural performance according to the low-yield-steel members of high strength steel and to predict the probability of upward movements and its applications in Korea.

The purpose of this study is to clarify the effect of the monomer ratio on properties of the polymer-modified mortars based on re-dispersible polymer powder, and to obtain basic data necessary to develop appropriate latexes for cement modifiers. This paper deals with the effects of monomer ratio on the typical properties of the polymer-modified mortars with re-dispersible polymer powder. The polymer-modified mortars using the re-dispersible polymer powder are prepared with different polymer-cement ratios, air contents, water-cement ratios, flexural and compressive strengths. From the test results, the polymer-modified mortars using re-dispersible polymer powder can be recommended for practical applications. Their basic properties are greatly affected by the polymer-cement ratio rather than the polymer type, and are improved over un-modified mortar.

As structures are high-rise and bigger, the demands of high strength steels have enabled it to be produced which have excellent properties such as strength, ductility, weldability and toughness than conventional steels do. Computer models of WUF-B connection were formed and analyzed using the finite-element analysis computer program of ABAQUS. The analysis model is based on the test program using high and normal strength steel. In general, the failure mode and maximum deformation obtained by test could not be simulated from the finite element analysis specially for the cyclic loading. The maximum equivalent strain and accumulated plastic strain obtained by FEA were found based on the cyclic test result at the failure. The applied load history of FEA model was traced as same as the cyclic test until it failed. And, the accumulated equivalent plastic strain was selected to find the global deformation capacity of connection at failure. Analysis results show that the selected maximum accumulated equivalent plastic strain at failure for different strength, normal and high strength steel, are different. The suggested plastic strain could be used to find numerically the limit of deformation capacity of beam-to-column connection, which results in the reduction of expensive test.

The column-supported wall system structures are being built according to increase of population and accelerated urbanization. In this study, characteristics of shear wall system subjected to lateral load is analyzed and the stress distribution and deformation characteristics of the column-supoorted wall system structures were compared. The results obtained from the model using the plane stress elements were compared with the results of the model with a beam-column elements for column - supported wall type structures. The bending moment of the model with beam-column elements was 0.53 times of that of model with plane stress elements at the end of transfer girder. And the bending momomet at the center of transfer girder consist of beam-column elements was 1.59 times of that of model with plane stress elements.

The column-supported wall system structures are being built according to increase of population and accelerated urbanization. In this study, characteristics of shear wall system subjected to lateral load is analyzed and the stress distribution and deformation characteristics of the column-supoorted wall system structures were compared. The results obtained from the model using the plane stress elements were compared with the results of the model with a beam-column elements for column - supported wall type structures. The bending moment of the model with beam-column elements was 0.53 times of that of model with plane stress elements at the end of transfer girder. And the bending momomet at the center of transfer girder consist of beam-column elements was 1.59 times of that of model with plane stress elements.

There are many buildings that need curtain wall system with increment of high-raised buildings. It is important to design curtain wall system effectively and economically in order to have the buildings to be safe and inexpensive. In Korea, there are very a few specifications to control the design of the curtain walls and each specialists has different skills or procedures to design curtain walls. These facts make the communication difficult one another. Therefore, there is a strong need to develop a series of procedure to design curtain walls. This Study had summarized whole process of curtain wall system construction on buildings and developed the evaluation worksheet which can easily examine the curtain wall member's such as mullions and transoms stability through analyzing the structural design reports and previous studies.

In the country designated as national treasures and cultural treasures, was built in most of the timber. These traditional wooden structure are state on degradation and deformation caused by deterioration, and it's about time that maintenance and preservation should take a deep interest. However, the current maintenance and preservation are carried out by the previous experience of carpenter, these bring secondary deformation and degradation because did not identify the exact reason, and it is the reality of our maintenance and preservation of cultural assets. Therefore, future maintenance and preservation of traditional wooden buildings should be followed to the scientific and structural approach. So, this study choose unit member where many damages happen to structural members of wooden cultural property, and made 8 specimen of rectangular section of flexural member to understand the structural behavior and phase by reinforce damaged members with synthetic resin. The results of the experiment, the most neutral axes of specimens are located at the opposite of the reinforced part. If the neutral axis moves to the reinforced part, the maximum strength is expected to be improved. And the compression is judged to be effective.

The objective of this study is to determine the possibility of re-using waste concrete. The strength test was conducted with four aggregate compounds(0%, 15%, 30%, 50%) which were replaced a natural aggregate with recycled aggregate. For the relatively comparison between natural and recycled compounds, while the unit aggregate weight was changed, other conditions were fixed. The results of experiments showed that the strength value was usually similar or decreasing within the limites of 50 percent and blow and the best of it was 30% of replacement ratio because recycled aggregate includes high rate of absorption and adhered mortar. As a result, recycled aggregate concrete with mechanical properties of plain concrete can be used as an alternative.

In this study, experimental research was carried out to improve the structure performance of R/C interior beam-column joints without shear reinforcement using high ductile fiber-reinforced mortar. Test result shows that retrofitting specimen(IJNSP1.0) designed by the improvement of structure performance of reinforced concrete interior beam-column joints, maximum load-carrying capacity was increased 1.1 times in comparison with the standard specimen. The retrofitting specimen(IJNSP1.0, using high ductile fiber-reinforced mortar, designed with no shear reinforcement) show similarly load-carrying capacity although without shear reinforcement in comparison with standard specimen. For such joint, it is considered efficiently to attain shear performance.

In this study, experimental research was carried out to improve the seismic performance of high-strength reinforced concrete interior beam-column joints using advanced reinforcing detailings. Test result shows that retrofitting specimens(IJIR, IJIRS) designed by the improvement of earthquake-resistant performance and ductility using advanced reinforcing detailings could attained more maximum load-carrying capacities and stable hysteretic behavior. The maximum load-carrying capacities of each specimens were increased 1.3～1.4 times in comparison to standard specimen.

As an importance of new and renewable energy increases, scientists are actively studying photovoltaic system. Nevertheless solar collector, an important part of photovoltaic systems, has been ignored by people. Even though there is need of study to make up for the weak points. Solar collectors, which is installed on house surface usually roof, are easily effected by wind but wind pressures of solar collector are not included in KBC2009. Therefor, we made solar collector model and conducted on wind pressure test in wind tunnel facility and investigated how the model is being effected by four seasons at two different places such as roof and ground. Based on these results, basic wind pressure distribution of the solar collector module is provided. This can be useful data for the wind resistant design of solar collector module.

In this study, experimental research was carried out to evaluate the structural performance of reinforced concrete beam-column joint using steel plate, carbon fiber, and aramid fiber materials in existing reinforced concrete building. Test result shows that Retrofitting specimen (LBCJ-SP45, LBCJ-CS1, LBCJ-AF1) designed by the improvement of structural performance and ductility using various materials(steel plate, carbon fiber sheet, and aramid fiber sheet) could attained more load-carrying capacity and stable hysteretic behavior. The load-carrying capacity of each specimen was increased 25.8~49.5% in comparison to standard specimen.

The PC composite wall typically consist of two outside 4cm thickness layers surrounding a cast-in-place 10cm thickness reinforced concrete layer. The outer layers are usually constructed of precast concrete and connected by kaiser truss connectors through the cast-in-place reinforced concrete layer to form a structural composite panel. An objective of this study is to evaluate the compactness of the infilled concrete in the precast concrete composite wall. The test is consisted of three stage which are the ultra-sonic test. Test results was obtained the proper material type and the pouring method of the infilled concrete.

This study is to discuss the issues with the change of the angle of inclination when forming the tension-field in the high-rise structures under the lateral force. The high axial and flexural column forces caused by the high overturning moments would decrease the overall stiffness of the shear wall, and the change of structural mechanism may induce the change of the angle of inclination. So, the analysis study was performed with four finite element models, 3, 9, 14 and 20 stories. Each model was classified in shear and flexure mode by comparing to the strength of estimates calculated by the equation and analysis results. In the model of shear deformation mode, it was showed to form constant angle to cause tension-field by checking the principal stress vector.; whereas, the column plastic hinge occurs bending deformation in flexural mode and the change of tension-field according to the mechanism showed highly differences from the existing theory.

An analytical study was performed to apply upgrading design of the shape of established transmission tower. Finite analysis of transmission tower using beam element and shell element perform and Propose of analytical ultimate strength of member based on nonlinear analysis of local and partial finite element model used. Providing an design guide to development of limit state design specification for electric transmission tower.

Since high-rise buildings require satisfaction of building drift limit due to lateral loads, steel plate shear wall system appears to resist the lateral loads instead of reinforced concrete wall system. But, there is lack of research and understanding of steel plate shear wall system so that no real building of such system exists in Korea. In this study, Standard SPSW system based on the coupling beam connections in parallel with the structure of the steel plate shear walls in a study to assess the performance analysis includes information. For this purpose, a coupled steel plate shear walls with various parameters it is verified by analysis.

This paper investigates the interaction of structural steel reinforcement and strain-hardening cement composites (SHCC) in uniaxial tension. The effects of cement composite on the steel reinforced composite deformation behavior are experimentally investigated and contrasted to conventional reinforced concrete. Also, Using an expansive admixture can reduce an initial shrinkage crack and improve a prestress. Axial tension members made of both normal and high strength concrete are used to investigate tension stiffening and cracking of SHCC to determine experimentally if any relationship exists between SHCC strength and post-cracking behavior. Tension stiffening represents the tensile strength of concrete between cracks in a reinforced concrete member and can significantly affect member stiffness, deformation, and crack widths under service loads. A specimens using 30 and 100 MPa SHCC were reinforced with D16 bars. The presence of fibers controlled the splitting cracks and led to significant increases in the tension stiffening of SHCC using an expansive admixture

In this study the lower column of RC frame structure received shock due to abnormal load, and when a 3D modeling is carried out by a Zeus-NL program, a Push-down analysis was executed after the column receiving shock is removed from the 3D modeling. The X-tract, which is a nonlinear section analysis program, was used for analysis of a member such as columns and beams of each floor. The case that an inside column received shock and the case that an external column received shock were decided as a variable of analysis, and its analysis was performed for 5, 10 and 15 storie buildings, and then the moment and deflection of structures were compared with each other for progressive collapse. As a result, the stress was concentrated to the beam that a column was removed, and as it goes up to higher stories, the moment change of an upper story appeared less and the deflection also showed an analysis value trying to maintain horizontal.

Recently, P.E.B systems with tapered section shape are usually used in steel factory and warehouse. The tapered shape provides the effective cross-section performance considering the difference in the stress distribution of member. Therefore, this study presents the initial topology decision method of steel structure considering tapered shape. The optimal topology of tapered shape structure is obtained by performing topology optimization according to design constraints and load conditions. Through the application results, we can find out the reasonable initial shape of steel structure with tapered shape.

The purpose of this study was to investigate the effect of finish surface coatings on the chloride attack resistibility of concrete. Recently, There has been studied for the amount of chloride penetration into concrete, but the actual construction has been built through of various finishing method except of exposed concrete. therefore, this study was tested using finishing material while investigate the amount of chloride penetration into concrete. As a result of this study was obtained as follows, 1) There is chloride ion penetration quantity of none-coating concrete more then coating concrete. 2) Chloride attack resistance of dry-vit(D) is the best among the used materials. 3) There is type, physical property and thickness of Finishing material that is affects to the chloride ion migration coefficient test. 4) This study identified amount by depth and distribution of Chloride Ion by using the Nernst-Planck equation.

In this study, researchers directly experienced the feasibility of co-housing on the basis of analysis proceeds from sale of land purchase and construction cost of the imported items and expenditure items such as cash flow analysis table was created based on (Cash Flow Sheet) are correct and each expenditure A number of factors have a direct impact on the simulation analysis, and subsequent analysis of the problem by introducing an alternative to the ones you want to do real estate development future direction of research aims to present.

The concrete which is the porous material is exposed to variety outside environments so the moisture from environments permeates into the concrete. As time passes, volume of absorbed water and moisture distribution are changed in internal concrete. These moisture diffusion has caused various problems such as penetration of acid rain, neutralization and freezing and thawing in the aspect of durability of concrete structures. The moisture in concrete involved in movement of deterioration substances and the reaction. The concrete depends on the internal pore distribution, size, and shape by mixing conditions, So behavior of moisture diffusion in the liquid phase is different. The some study on moisture diffusion of concrete has been studied, however The study on quantitative evaluation of moisture diffusion coefficient according to variety mixing conditions has left much to be desired. The purposes of this study is consideration through experiments about relationships between properties of concrete according to a variety of mixing conditions and moisture diffusion coefficient. As a result, moisture diffusion properties of concrete were greatly influenced by mixing factor deciding volume of voids of internal hydration organization.

The objective of this study is to scrutinize certification effects and improvement schemes of the ISO 9001 quality management system. The ISO 9001 is a system adopted to improve the quality and effectiveness of the construction industry in the Busan province. However, many of growing companies are certified in certificate revocation. This paper consists of four chapters and based on the field survey such as visiting interview, mailing, and phone-calling conducted for two weeks. The survey targets were the Busan ISO 9001 certified manufacturer change, satisfaction, utilization and the competitiveness of the positive aspects and negative aspects divided into. By analyzing the survey results, improvement plans were considered for issues.

To effective management and the construction time, cost saving, Korea has imposed Construction Management that has been developed sharply. Because the demand of Construction Management has increased, work duties or research on Construction Management are progressing at institutes. Although lots of research has progressed, research which is analyses on CM work elements and guidelines is insufficiency. This study makes the process of CM works suitable for Korea's law and construction practice to solve these problems. And actual procedures operated will be understanded by doing a survey. By comprehending duties that are performed by CMr, this study drew actual construction management tasks in construction site. Also effective manpower, time share are expected in the performance of construction management tasks. This study are expected to can assess CMr's performance and skill.

When placing concrete, due to delay placing of concrete occurs in treatment of Cold Joints. It required a separate equipment and additional personnel, in addition, equipment costs, labor costs and material costs are increased. So, in the field be no special treatment is common to place concrete. By the analysis the increase in quality of Cold Joint process through the Alkali-hydration reaction effect to promote higher strength for hardening concrete. Research includes properties for Laitance and alkali activator to present the way of treatment for Cold Joint surface process. To consider workability and economical facts in application of the construction field, research implemented by using the way to jet alkali activator with Cold Joint surface. At the result, it is founded that concrete fulfilled excellent strength in the case which uses Calcium Hydroxide with Potassium Hydroxide + Potassium Sillicate and this is regarded as the alkali activator excellent Hydration reaction effect efficiently at Cold Joint surface.

The purpose of this study is suggesting a basic data for which scientific preservation and rehabilitation of modern architecture through the analyzing property of clay brick used in modern masonry architecture. The clay brick which is used in the early 1900s has even lower properties such as compressive strength and absorbing ratio than present clay brick because of poor firing technique at that time. And, it could be possible to properties and effective stability estimation of modern architecture from nondestructive test which is significantly associated with properties.

In this study, Shortage of construction site workers would appear much higher than that now are judged. Thus, the issue of construction site workers can be improved through the survey. Practitioners to examine in detail their status in regard to the questionnaire items were deemed important. And in three categories are derived from details of construction workers on the potential benefits offered to analyze trends. In this paper, we survey of practitioners in the construction site in earnest to make the questionnaire was becoming an important key. Conducting surveys in the future if practitioners analyze the status of the personnel management system based on this scene by using the administrative functions required skilled manpower will be able to quickly locate and invest. Practitioners in the field of construction management which can be facilitating further two day laborers and construction workers and 3D industries construction site job not changed in recognition of professional technicians and construction site workers in the field as a result of their professional duty and obligation to the efforts of your technology also does not neglect improving quality and productivity of construction is expected to improve.

The construction time management is very important technique that is improving construction efficiency and cut construction expenses. But domestic construction companies have not practically implement the time management by shortage of skilled labour, education. Foreign construction companies are implementing efficient time management by legalisation related process. Both partial process technique is used and small business is virtually not skilled labour related process in Korea. Accordingly this study do forge region construction companies to reinforce a capability that is progressive better than past unsystematic or inefficient construction time management. That's in addition to forge the efficient time management and to develop a process. The efficient time management should operate small region construction companies to outsourcing.