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Reinforced concrete structure has been widely used thanks to its easiness to construct with longer service life, but it produces several problems such as crack, deflection and lowered strength of a structure due to various external and environmental factors like loading and earthquake. Researches are actively being carried out on repairing and reinforcing method to improve these problems. For the strengthening material mainly used at construction sites, steel plate and fiber can be counted in general, and for the fiber case, a composite material like glass fiber, carbon fiber and aramid fiber for reinforcing is commonly used in concrete structures. For the end development method, only the development effect has been verified through experiments without providing an effective development design per FRP strengthening quantity on a tensile surface. Further more, clear understanding on the cause of bond failure is not enough and the problem is that development of an effective development method to control it is not yet carried out up-to-now. Therefore, this study acknowledges the strengthening effect through behaviors of each specimen and test results by performing tests on total 4 reinforced concrete beams with the strengthening quantity and its position as variables in order to evaluate the performance of the Peel-ply method using aramid fiber plate to increase bonding strength with the basic material concrete.

In this study, the eco-friendly concrete using geopolymer encouraged alkali activation reaction has rapid hardening speed and showed possibility as a high strength concrete. Also, the RC beams applied this showed similar movement and destroy tendency with RC used previous cement. It is thought that eco-friendly geopolymer concrete can be used in construction material and subject matter as a basic research to replace cement concrete and if there is application to structure subject matter in PC form as well as production of 2nd concrete product can improve the productivity, concrete for reduction and more of efficiency.

Unreinforced masonry (URM) occupies most of low-rise residential buildings in Korea. In this study, the validation of reliability for the push-over analysis using Midas Gen program has been performed based on the results from domestic experimental research regarding to masonry walls. This study was progressed the evaluation of capacity for domestic existing prototype masonry building, and evaluate seismic fragility curve of URM building. In comparison with existing fragility curves, the damage probability for each model are 1∼5% higher.

In this paper, we carry out tensile testings to estimate the ultimate capacity of block shear rupture with parameters considered in case of the single angle, H-shape section. The resurt is that the joint happened. two types, tension yield-shear ruptures and shear yield-tension ruptures. Tension rupture line, which is same as specification, happens in the center line of bolt hole, but shear rupture line happens in the outside line of bolt hole rather than in the center line of bolt hole which is specified in the specification. Shear rupture in this test was happened along the outside line of bolts. Thus, ultimate shear strength factor was larger than 0.6 due to the increasement of pure shear area. Also, it was a little bit larger than 0.6 when real shear rupture line was applied.

Voided slabs is by means to reduce slabs dead loads which curtails the amount perpendicular structural members and seismic loads by controlling the concrete loads. This research paper analyses the flexural behaviour of one- way voided slabs in relation to hallow and aspect ratios. For this flexural behavior of one-way voided slabs analyses, I’ve set the model variables of hollow ratio up to 50% by 0%-5% unit, aspect ratio up to 2.0 by 1.0-0.1 unit and used a general structure analysis programme to model a 3D one-way voided slabs. The results displayed a moderate drooping of hollow ratio above 35% and not much considerate alteration to aspect ratio. An appropriate level of hollow ratio seems to be 20-35% from this research.

In this study, experimental research was carried out to evaluate the structural performance of the reinforced concrete beam retrofitted by strengthening methods(embedded CFRP rod of hexagon, metal fittings) in existing reinforced concrete buildings. Test results showed that the maximum load carrying capacity of retrofitted specimens(BCR2-AC2, BCR3-AC2) were increased by 53% and 74% respectively in comparison with the standard specimen BSS.

The solar collectors were affected by Typhoon Bolaven last year, because they are mainly a lightweight structure and directly exposed to the outside. Nevertheless, a study on wind pressure of solar collector is not sufficient. Therefore, It is necessary that a study be conducted to discover the effect of separation distance on solar collectors. This study conducted the wind tunnel test to analyze the distribution of the wind pressure in accordance with the separation distance of solar collectors. wind tunnel test conducted by changing separation distance to 0.3m, 0.5m, 1.0m. As a result, the study can be the useful basic data to set standards for safety technology in the solar collector.

A form-finding process of tensegrity structures with decomposition methods is observed. Our observation is particularly focused on the application of singular value decomposition (SVD) to the force density matrix in the form-finding technique based on force-density method. Note that the SVD has been usually used to decompose the equilibrium matrix to confirm whether the final tensegrity form is in equilibrium. Three plane tensegrity structures are used in this observation.

Recently, Korea design codes about CFT columns were indicated. Such are the Specifications and Codes for Allowable Stress Design by Korean Society of Steel Construction in 2003 and Korean Building Codes for Limit State Design by Architectural Institute of Korea in 2005, which was revised in 2009. However, KBC/LSD provision underestimate the strength of CFT columns. Therefore, more accurate estimation of strength of CFT columns is needed. Current research performs column tests under eccentric axial load and investigates buckling loads of the columns in inelastic range. It also compares the test results to KBC/LSD provision. This paper suggests new design method of CFT columns for KBC/LSD provision.

The purpose of this study is comparison and analysis between standard impact source and human impact source. also showing characteristic of general slab and hollow slab when each impact sources is applied in general slab and hollow slab and comparing and analysis of characteristic in slab. As a result, load of tapping machine was difference to load of human light-weight impact source. and bang machine had difference on load. so we think we need additional studies about standard heavy-weight impact source to supplement this difference. and we can have decreae load of running impact source if we will use hollow slab having hollow proportion under 40% in application of slab about running impact source.

The purpose of this study was to investigate the optimal fiber volume fraction in concrete mixed with recycle aggregates. In this study, a total of 9 variables (① 0% steel fiber content with PVA fiber contents of 0%, 0.25%, 0.5% ② 0.75% steel fiber content with PVA fiber contents of 0% 0.25%, 0.5% ③ 1.5% steel fiber content with PVA fiber contents of 0% 0.25%, 0.5%) are set. However, 30% replacement ratio of recycled aggregates and 35% water-cement ratio are fixed. The results of the compressive strength (0.75% steel fiber, 0.25% PVA fiber content), the splitting tensile strength (1.5% steel fiber, 0% PVA fiber content) and the flexural strength (1.5% steel fiber, 0.5% PVA fiber content) show the excellent material performance.

The most fast, effective and simple method is external bonding. Traditionally steel plates bonding was done in Europe, USA and Japan. But there is requirement to find other method beside steel plates, because of corrosion and weaken heat-resisting property of steel. For this reason FRP(fiber reinforced polymer) composites have been used since 1980’s FRP composite materials has high resistance to corrosion, tensile strength and high fatigue strength rather than steel plate. Therefore this way to strength is known as suitable method. In addition, according to different reinforcing pattern, quite a few reinforced concrete structures using FRP reinforcement for reinforcing study show various result. Therefore, our purpose in this study is that analysis reinforcement effect according to various reinforcement patterns.

CFRP retrofit in concrete members has various applications owing to its advantages of constructability and performance. The currently popular surface retrofit method frequently experiences reduction of attachment performance which is most important in CFRP retrofit. To resolve the problem, Near-Surface-Mounted Rertofit (NSMR) method was developed and being studied. In this paper, experimental and analytical study were performed to find the effect retrofit length and effective simulation method for the flexural behavior of RC beam strengthened by NSM CFRP. Nonlinear finite analysis as well as nonlinear sectional analysis for the RC beam were conducted by considering the bond characteristic in the connection and the results were compared to the experimental one. Test result indicated that the longer bond length the specimen had, the higher ultimate strength was shown. And the load-deflection behavior of RC beam strengthened by CFRP plate could be suitably simulated by using nonlinear sectional analysis approach.

In this study, the effect of strength improvement on concrete were found on several different replacement ratio of recycled aggregate mixed with blast furnace slag, replacement ratio of fly ash, and material age. The effect of strength improvement were evaluated by compressive, tensile and flexural strength. As a result, the recycled aggregate without blast furnace slag showed the highest compressive strength with 20% of fly ash And tensile and flexural strength were highest with 10% of fly ash. In the case of compressive, tensile and flexural strength on 30% of recycled aggregate showed the highest performance improvement with 10% of fly ash. On the other hand, 30% of fly ash showed the lowest strength

Generally speaking, as time goes on common RC structures are weaken by various reasons. But rebuilding of reinforced concrete structures is hard from economical and environmental reasons. For this reason many researchers considered about structure reinforcement. A Study has been constantly on FRP (fiber reinforced polymer composite) for reinforcing RC structures. Therefore a purpose of this study is to analyze effect of CFRP(carbon fiber reinforced polymer) for estimate long-term performance of FRP strengthened RC beams.

This paper focuses on the evaluation of bond strength of the CFRP-bar to concrete joint with NSM system. Based on the existing mathematical models, the bond strength variables such as sectional shape and perimeter of surface bond length, effectiveness of anchorage system, will be evaluated. The contributiveness of variables will be shown through the experimental test result and With these test result and indexes valuated, this paper provides basic data of the bond strength about the CFRP-bar to concrete joint with NSM system.

Recently occurred at the 7.0 scale earthquake on 2010 Haiti, 8.8 scale earthquake on Chile, 6.3 scale earthquake on New Zealand and 9.0 scale earthquake on East Japan As we can see from the occurrence of earthquakes Directly, the Number of casualties, economic loss and urban infrastructure failure due to the industry is huge indirect losses. In recent years, 2011 9.0 scale earthquake on East Japan after the occurrence, Korea also has the not safety of the earthquake existing building evaluation of the seismic performance and seismic retrofit. First, the school building gradually work this.

In this study, Beam-column joint specimens of building structural steels(SN490) and welding structural steels (SM490) were conducted lateral cycle test. The experimental method was conducted Certification testing methods presented in KBC2009. Through experiments, Hysteretic behavior of Load-displacement, Moment-Rotation angle ductility, stiffness and energy dissipation capacity was analyzed. Specimens type is all welded type(WA-1, WA-2) and welded flange, double angle spliced web(WB-1, WB-2) total 4 types. Instead, fracture occurred at heat-affected zones or the stress- concentrated point near the weld access hole of the beam flanges.

The study on, in case of mix the existing Industrial by-products in the modified sulfur and Ordinary Portland Cement, According to the mixing of the modified sulfur, the compressive strength and durability property tries to be analyze. The test result, When mixing modified sulfur compressive strength increases 3∼6% based on 56 days of age but difference is small. In the case of the tensile strength, it confirmed that it increases 6∼11% based on 56 days of age when mixing the modified sulfur. In terms of chemical resistance of concrete when mixing the modified sulfur carbonation 10∼20% was slow progressed. In case of chloride penetration depth 15∼38% resistance was excellent and in the case of the Sulfate resistance 32% was excellent.

Recently the government enactments "Promote and suppor for small and medium industry's products of law" which sets conditions for shared growth of major industry and small and medium industry. However this system has many problems at material procurement and overburden staff who is in charge of material procurement. So this system needs improving at application. Through this study, we will rebuild integrated material procurement process through the analysis and deduction of the main factors for successful and efficient material procurement process in construction project.

The human resource management in site is one of the most important factor for project success. Generally, supply of most field workers rely on off-line human market, it makes many inefficient wastes in human resource management process. The purpose of this study is to analyze problems in current off-line supplying method for hiring and managing irregular field worker process, and to suggest systematic process using online supply-demand system.

As the construction of information technology systems for construction projects increasingly larger and more complicated as systematic management of construction projects, and in a similar business plan in the future for the purpose of information arising from the construction site to reflect the accumulation, to take advantage of the processing, interest and importance is increasing. This research will suggest the direction of improvement of construction fieldworks and derive the priority of each scene seeks to provide direction for improvement in the business.

High-rise buildings to reduce energy consumption and environmental impact of the high-rise buildings that make up the outer shell of the curtain wall material for research and development, compared to the current one urgent domestic overseas a lot and leaves much. This scene can be easy, inexpensive construction curtain wall method of construction for eco-friendly performance and wind loads and seismic identification and structure safety for full-size Mock-UP for testing, such as sustainable building exterior of the required performance. Following this, ALC panels for construction life cycle from the point of sustainable environment-friendly method to complete with a figure-of-merit for evaluation of various items to each other.

In an effort to resolve environmental pollution problems, developed countries enforce green building certification systems such as LEED, BREEAM, CASBEE, etc. South Korea also introduced green building certification system since 2002 for energy-saving and environment-friendly residential environment, and implements incentive systems. However, there are some problems in activating the system the due to a lack of understanding of systems and the problems related to cost distribution. Thus this study will suggest the basic data for decision making from the view point of orderers through a feasibility study according to the incentives in green building certification system.

Lately the construction market using modular system, which is one of dry construction methods, is increasing rapidly. Furthermore the demand of urban living homes using modular system due to happy home project is expected to increase. However, due to low awareness of this construction method and uncertain economics compared to conventional construction methods, the purchases by private consumers are inactive. Thus this study will conduct an economic analysis by calculating cost and profit by construction method in order to provide basic data for establishing directions for the projects in the future and making decisions.

Recently, as the national policy of green growth is promoted, construction field also makes an effort to reduce CO2 gas released when producing cement continuously. Also to prevent environmental pollution and solve waste treatment, the use of industrial waste such as red mud and blast furnace slag has been studied for a substitution material of cement. Thus, in this study, physical properties of ternary system concrete mixed with red mud was investigated, and to know an optimum mixing method, the volume fraction of red mud and blast furnace slag was varied.

Analysis of the drying efficiency characteristics of heated veneer rolls demonstrated that the heating efficiency varies depending on the thickness of the board and its board during heating. And the roll shape showed superior drying quality, Thermal distribution and weight & moisture content reduction when heated, in comparison with the board shape.

The study identified the efficiency of the new technology, No.618 and No.660, which are the crack control engineering of the mat concrete, developed by the research team, by applying both in the field at the same time. The efficiency is attained by analysing the overall mat concrete properties and the hydration heat temperature hysteretic characteristics First of all, as the fresh concrete characteristics, slump, air content, chloride content and concrete temperature satisfied all the target values. The compressive strength of the hardened concrete at the age of 7days and 28days met the nominal strength required by the orderers. From the measurement of the temperature hysteretic characteristics, the temperature gap between the center and the surface of A and B sector, which can be caused by the casting time difference at the initial time, was minimal. The maximum temperature of the middle part of A sector was 59.6℃ and 55.6℃ for the surface. In the B sector, 54.6℃ and 48.9℃ respectively for the middle part and the surface. So there were no cracks caused by hydration heat in the sector A and B. Both, A sector and B sector generate the hydration heat in the upper and lower part of the concrete at the age of 8~9 hours. But the cracks did not occur because Double Bubble Sheets insulated the surface and reduced the temperature gap between the middle part and the surface. Finally the study confirmed that for the hydration heat crack control of the mat concrete, new technology No.618 and No.660 are recommended to be used at the same time.

Cement has been widely used in the construction and civil engineering field in the past decades. The environmental pollution has been increased by emission of CO₂and harmful gases. So research on the development of alternative materials is an urgent situation. Therefore, In this study, To reduce emission of CO₂and harmful gases produced for result of cement production evaluated mechanical properties ranging from the high intensity by manufacturing mortars mixed industrial by product of blast furnace slag(Granulated Blst-Furnace Slag; GBFS), the newly emerging admixture meta-kaolin and two alkaline activators.(최대 6줄만 입력가능)

A recent installation of rainwater harvesting system have been increased and all of rainwater harvesting system use its roof surface as water catchment area. However, it has limited uses because of limitative catchment. Therefore this thesis suggest way of collecting rainwater in not only roof surface but building wall if place of high population density like metropolis use rainwater as water for living. To achieve this, we do experiment work in a rainy day using three of scaled model which have different slenderness ratio and evaluate possibility amount of collecting rainwater through the building wall. In addition, we compute a water catchment coefficient to provide baseline data about collecting rainwater in building wall.