This study is to analyze the properties of concrete according to the types of binders and cement powder and to utilize them as fundamental data for the development of early strength concrete. In the case of fluidity, all of the formulations satisfied the 180±25mm, and the flowability of HSF was decreased by high fineness cement. For the air content, 4.5±1.5% of the total content was satisfied. Compressive strength of HSF was found to satisfy the 5MPa in 2days of aging. In case of 28 days of aging, the strength of HSF was more than 24MPa.

As the importance of maintenance of reinforced concrete structure recently has emerged, the attention of durability of structure has been increasing. There are many studies about durability decline especially due to the carbonation. In order to study carbonation progress after surface repair of carbonated concrete, each carbonation penetration velocity from different repair materials of concrete structure is compared through the experiment of carbonation accelerating CO₂ concentration to 5%. As carbonation infiltration progress is predicted through this study, the counterplan of service life evaluation will be prepared on selection of repair materials of concrete structure.

For the structural analysis of reinforced concrete structures, the mechanical properties of concrete at each temperature are required and the mechanical property values according to specific temperature are presented in the design regulations and codes. In this study, the mechanical properties of concrete were experimented by using 35MPa concrete produced in Korea from 20℃ to 900℃(two kinds of test method). Compared the results with previous domestic papers, we aimed to contribute to the construction of mechanical characteristics D.B. of at the elevated temperatures of domestically produced concrete which can be used for structural analysis in fire.

The properties of concrete produced by ready mixed concrete company in Busan were tested. Because the concrete was mixed with blast furnace slag and fly ash, the compressive strength and chloride ion diffusion coefficient were lower than OPC concrete even though the specified concrete strength was same. If the durability about salt attack were satisfied, the concrete of lower specified concrete strength would be adopted to concrete mixing design.

Red mud is an inorganic by-product produced from the mineral processing of alumina from Bauxite ores. This study is to investigate characteristic with respect to curing conditions according to the red mud content. The results best of best showed that the water curing compressive strength better than atmospheric curing, steam curing.

In this study, the flexural behavior of fiber-reinforced concrete by fiber type were evaluated. As a result, the flexural strength of the hooked steel fiber-reinforced concrete(HSFRC) was lower than that of the amorphous metallic fiber reinforced concrete(AFRC), however it was shown strain-softening behavior by the pull-out of fiber. The flexural strength and the equivalent flexural strength of polyamide fiber-reinforced concrete(PAFRC) were lower than other specimens, but the equivalent flexural strength ratio was similar to that of AFRC. The flexural behavior of the fiber-reinforced concrete was associated with the bonding and pull-out properties of the fiber and matrix depending on the fiber type.

This study is to provide a evaluation method for the penetration depth of emulsified refined bio diesel(ERBD)applied to a surface of the concrete by using water absorption capability of the concrete. The concrete applied with ERBD was immersed at water for 1 min., 5min., and 10 min. and then was checked the brightness with elapse of time. Test results indicated that there was clear difference between ERBD part and non ERBD part in concrete specimen after measuring the brightness until 120min.

In this study, fundamental properties by pore structure and heat of microhydration test were determined. As a result of pore structure analysis, BS(AA) specimen showed showed the maximum peak value of significantly lower incremental intrusion than the maximum peak value of incremental intrusion at smaller pore size than that of BS. As a result of heat of microhydration test, the maximum heating value was in the order of OPC > BS > BS(AA), and initial drying shrinkage and compressive strength of BS(AA) were expected to be improved.

This research aimed to analyze the fundamental properties of cement mortar accompanying the change of solid contents of PC type water reducing agent. As a result of the experiment, in the case of flow to the properties of the fresh mortar, it shows a tendency to decrease as the solid content ratio decreases, and the decrease width with the passage of time is greatly reduced when 30 minutes passed since the passage of 60minutes It turned out that it was. In the case of the air contents and the compressive strength, it was found that there is almost no difference due to the change in the solid contents.

Gamma-C₂S (γ-C₂S) is a substance that is difficult to react with water under normal temperature but can absorb a large amount of CO₂ in the air. The addition of γ-C₂S to cementitious materials through the curing of CO₂ can improve the pore structure and improve the durability of the material. In this study, three kind of Ca-bearing materials : CaO, Ca(OH)₂, CaCO₃, were calcined 2.5h at 1450℃ to synthesize γ-C₂S after mixing with SiO₂ respectively. Among them, Ca(OH)₂ mixed with SiO₂ after calcining shows highest content. Synthesized γ-C₂S was added to the cement mortar, after water curing for 1 month, accelerated carbonation test was experimented. After 28d accelerated carbonation test, pore structure will be detectived by MIP. Based on the MIP result, following the calculation method of Fractal theory, the pore structure will be quantitative described.

Oyster packs generate about 150,000 tons a year. Various studies are under way to utilize this oyster shell. Ca is the main component of oyster shell and is used as a raw material of refractory board. Studies on application of refractory board using oyster shell are also continuing. It is expected that the refractory characteristics will be improved as the mass of oyster shell, that is Ca, increases. In this study, mortar specimens and board specimens were fabricated by increasing the mass ratio of oyster shells classified below 0.6mm, 1.2 ~ 0.6mm, 2.5 ~ 1.2mm and 5.0 ~ 2.5mm, and the strength and fire resistance characteristics were examined.

For this study, alkali-activated slag red-mud pavement is manufactured to examine the usability of red-mud as a recycling material in the construction industry. In the compaction curve in terms of the replacement ratio of red mud by binder type, the dry density changed gradually depending on the water content, which implies that there is no distinct difference in compaction according to the replacement ratio of red mud. The compressive strength at 28 days was observed to be 18.9~27.0MPa in ASS, and 18.4~28.8MPa in OPC, showing a similar level between the specimens.

The objective of this study is to evaluate the performance of polymer-modified surface preparation mortars with pozzolanic materials for corrosion prevention method in deteriorated sewage treatment structures. The prepackaged-type surface preparation mortars are prepared with a polymer-binder ratio of 10%, ground granulated blast furnace slag contents of 0, 15, 30%, a fly ash content of 15%. And, the specimens are tested for workability, adhesion in tension, water absorption, crack and impact resistance. As a result, the prepackage-type surface preparation mortars for sewage treatment structure are satisfied with quality requirements by KS F 4716, Japan sewage work agency(JS) and JIS A 6916 for surface preparation mortars.

In order to improve the flow performance of high performance concrete, use of high performance water reducing agent and low viscosity type water reducing agent is a study of suitable range of use due to side effects. in this study, we aimed at reducing viscosity and yield value using high performance water reducing agent and low viscosity type water reducing agent, and this was evaluated using a rheometer. as a result of analysis of viscosity and yield value, it was found that the high performance water reducing agent has higher reduction effect than the low viscosity type water reducing agent. however, the larger the viscosity lowering effect is, the lower the usable range is, compared to general high performance water reducing agents, and it was found that sufficient consideration for this judgment of appropriate quantity is necessary.

This study used Geopolymer to study tile waterproofing adhesives. The materials used in this study were polymer and acrylic resin, and were evaluated based on adhesion and water resistance. In particular, the adhesion was evaluated under various conditions, and the substrate was comparatively evaluated on the concrete and tile surface conditions.

In Infrared rays, which are 50% of sunlight, act as heat rays to heat buildings. Solar heat paint is widely used to protect buildings from sunlight. Solar heat coatings are used to block buildings form sunlight. Solar heat paints are classified as heat-reflective paints and heat-insulating paints according to the differential thermal mechanism. In this study, we study the thermal differential mechanism by analyzing the temperature change of the coated steel plate and the solar reflection spectrum on the surface. In this experiment, exposed steel plate, heat-reflective coated steel plate, heat-insulating coated steel plate, and general paint coated steel plate were used. As a result, when the infrared rays of 780nm ~ 1400nm were irradiated, the heat reflective paint had a temperature lower by 10 degrees than other paints. Analysis of the reflection spectrum of the paint shows that the heat paint is lower in heat than other paints because it has higher reflectance of light and absorbs much of the infrared rays.

This study aims to evaluate the humidity control performance of low-priced generic ceramic panels that are used to control humidity. Temperature and humidity are monitored by using 'Living Lab' and the change of indoor relative humidity is measured and analyzed. According to the results of the study, the indoor relative humidity of rooms installed with ceramic panels was found to be low compared to that of living rooms by 2.2%RH (test period) and 3.2%RH (daily). In the case of maximum relative humidity, rooms installed with ceramic panels were found to be low by 6.9%RH. The results are attributable to the humidity absorption of ceramic panels. Accordingly, future ceramic panels need the improvement of performance and an appropriate construction area should be derived depending on indoor space.

In this study, an investigation was made to study the chemical resistance performance of epoxy resin injection type leakage repair material used in the Korean construction market in accordance to the test method outlined in "ISO TS 16774, Part 2; Test Method for Chemical Resistance." This is a new standard document used for quality control method of injection type repair material used for leakage cracking of underground concrete structures. The results of this study can be expected to be utilized as reference data that can be used for quality improvement of the maintenance methods for future construction.

In this study, mortar strength was measured by grinding oyster shell and changing the particle size distribution. For the experiment, the oyster shells were processed to a fine aggregate size of 10mm or less. In this experiment, seven particle size distribution conditions were selected and tested. Because oyster shells are different in density from sand, their volume ratios were calculated and converted to mass ratios of 1: 3. The strength test was carried out one day after the steam curing.

As the environment and energy problems such as global climate change (global warming, urban heat island phenomenon) and energy depletion have come to the fore, the construction and waterproofing industry are responding more critically to the demands of global green technology and are employing more eco-friendly technologies as of recent. In this study, the application of the waterproofing material with thermal response performance in construction buildings was investigated to confirm whether the thermal performance is being properly secured by the change of the surface temperature. Experimental results showed that the surface temperature difference between before and after the application is at least 19.8℃ at the maximum 26.3℃. When the degradation rate is converted, the degradation effect of about 40% on average was confirmed.

The substrate behavior response testing outlined in KS F 2622 evaluates the leakage cause of waterproofing membrane systems when subjected to the concrete joint load behaviors by removing the waterproofing layer after testing, relying mostly on visual observation and subjective analysis. A non-destructive leakage cause and failure type analysis method is proposed currently in this study by the means of detecting leakage paths using thermal emission imaging systems. Test specimens are placed in varying temperature conditions after the concrete joint movement testing and are scanned using the thermal emission camera to determine the location and dimension of the adhesion failure/leakage path beneath the waterproofing membranes.

The safety accident of construction industries occur variously in other industries, including other industries, resulting in significant losses of human and material losses. In particular, General worker represents the highest safety accident rate each year, and the various types of accidents are the ones that show the greatest interest in the field, which is the most interesting job in the field. This study aims to identify trends in safety hazards and to analyze the accident severity for major types and influence factors.

Through the case study, we surveyed an applicability of digital fabrication in irregular-shaped building construction project. By digital fabrication, we mean is a precision manufacturing method has been used in aircraft, ship and car manufacturing industry. We collected construction-completed "LotteWorld Tower Podium" project data and analyzed its process in terms of construction quality andduration. The result shows that digital fabrication is considered a competitive technology that enabled to complete the project in seven months within 3mm surface curvature threshold. The digitalfabrication is expected to apply on a number of irregular-shaped building construction project.

The High-rise building has a problem the ventilation performance of natural ventilator by stack effect that it occurs by pressure difference. For that reason the study about natural smoke ventilator of High-rise building consistently needs. Therefore on this study does analysis of difference with abroad through investigate of Natrual smoke ventilator's law, it conducts of natural smoke ventilator's research on the actual condition. As a result on this study, in the case of abroad that it states more specific standards than domestic. Also the result of a field study, it shows that the natural smoke ventilator is installed same size and the number regardless of building's pressure difference.

Recently, the nation's elderly facilities have grown rapidly since the implementation of the long-term care law in 2008. Also, older adults who use older facilities are also growing. With the increase in the number of fires, increasing the number of fires is also a social issue. In this study, the study conducted an investigation into the smoke control system to analyze the smoke control methods of the elderly and elderly citizens in order to secure the safety of the elderly facilities in the event of a fire, and investigated the smoke control status of the elderly in Korea.

As the construction industry has been increasingly complex, aging workers, hard-working avoiding young generation, foreign workers having language problem for the past decades, delivering of construction qualified workers has been a rising problem. This misalignment between the complex jobs and the number of skilled workers will continue to be in issue that the construction industry will face for following decades. Construction field workers who are working outside in uncontrollable condition unlike manufacturing industry are exposed to easily construction safety accident. There are so many efforts to prevent and control the construction accident. However, the relationships between the construction works and construction safety accident has not been well dealt and investigated based on objective accident data except for the qualitative study through interview, delphi and so on. Therefore this study analyzes job risk matrix exposed to safety accidents based on statistic data for 20 years from Korean Occupational Safety & Health Agency in order to prevent the construction field accidents.

In this study, the initiation of steel corrosion was monitored due to chloride attack using embedded sensor. In general, Steel bars embedded in concrete are protected from corrosion by being forming a passive film on the surface. However, the passive film is destroyed by chemical erosion such as concrete carbonation and chloride penetration, and the rebar is exposed to the deteriorating factor and corrosion proceeds. In order to realize the initiation of steel corrosion, OCP and change of Impedance parameter were observed by using Half-cell and EIS method depending on cover depth. As result, 10mm cover showed the impedence increased in 6weeks.

Protective coatings at nuclear power plants should be designed to withstand exposure to ambient conditions during normal operation or design-basis accidents. However, there was a change in the perception of the protective coating to the revision of the Regulatory Guidelines by the NRC in July 2000. In other words, maintenance guidelines have been strengthened in order to minimize the clogging of the cooling water system due to the substances in the containment building. Therefore, KHNP, the contractor and operator of the nuclear power plant, plans to develop the coating system for nuclear power plants in accordance with the regulation, and plans to develop its own coating expert.

Early-frost damages easily take place in smaller and thinner walls and slabs. In case of slabs, it is difficult to visually determine the depth of early-frost damage. As such, the current study aims to determine the depth of early-frost damage caused to concrete structures due to bad curing in the winter. As a result, the study found that the depth of early-frost damages increased from the top as the atmospheric temperature on the concrete surface decreased. The changes in the color allowed the observer to easily identify the depth of early-frost damage with the naked eye. In particular, the color difference between potentially damaged parts and undamaged parts were the greatest around thirty minutes of drying after wetting.

In the case of korea, it was enforced the performance based design in 2011 for fire safety to the construction that is hard to safety secure by code based design. However as a result of domestic performance design case analysis, as it conducts that the standard is insufficient, most of cases show that they use the method of adding facilities by strengthening legal standards. Therefore on this study, it conducts the analysis of Performance based design seminar data that it was done by SFPE and each countries Performance based design guidelines. Also based on this, it will use the basic data for developing the domestic performance based design guideline.

Recently, The Building has became high rising and large scaling according to development of economy in domestic and other country, also the building has increased a variety of functions of insulation for warmth. and it has a symbol of economic growth, but it has risk factor for disasters such as fire. this hazards include not only general building but also residential building. Recently, Grenfell Fire that occurred in England has increased in combustion to the 24th floor of the 1st floor for 1 hour. it resulted in 80 deaths and 79 missing persons. In this study we suggest basic data of residential building for fire safety design related to domestic environment to analyze the problem of Grenfell Tower.

In this study, unlike high flowing concrete, using glass bubble to develop self-compacting concrete(hereinafter referred to as "SCC") with excellent filler performance by evaluating both flowability and yield stress, viscosity An experiment was conducted. Experimental results show that when 1 kg of glass bubbles are used, it is effective in stabilizing the physical properties of concrete, reducing the yield stress and viscosity.

In this study, it is speculated that the special admixture can be mixed with ERCO beforehand to prevent adsorption of cement and AE at the time of contamination together with water, and the change in the amount of special admixture preliminarily added to ERCO We will try to analyze the influence on normal strength mortar. As a result, the flow quantity, the air quantity, the compressive strength and the flexural strength were improved as the added amount of the special admixture was increased, and When the special admixture with the addition amount of ERCO 3% was added, the strength was rather lowered. Therefore, it was found that the optimum amount of special admixture added to ERCO was 2%.

In this study, the effect of insulation curing for mass concrete wall according to thickness and curing period was evaluated by thermal analysis.

This study examined the effect that the amorphous metallic fibers had on the static mechanical properties and the impact resistance of cement composites to those of hooked steel fibers. The hooked steel fiber exhibited pull-out from the matrix after the peak flexural stress was attained, while the amorphous metallic fiber was not pulled out from the matrix, but was instead cut off. In terms of impact resistance, the amorphous metallic fiber reinforced cement composite was found to be more effective at resisting cracking than the hooked steel fiber reinforced cement composite. Therefore, amorphous metallic fiber should be used in fiber reinforced cement composite materials, and for structural materials, and for protection panels.

This study analyzed the compressive and flexural strength characteristics and the permeability coefficient of the trial product of amorphous metallic fiber reinforced porous block using high volume blast furnace slag powder.

In the construction site, it is necessary to estimate the compressive strength of concrete in order to adjust the demolding time of the form, and establish and adjust the construction schedule. The compressive strength of concrete is determined by various influencing factors. However, the conventional method for estimating the compressive strength of concrete has been suggested by considering only 1 to 3 specific influential factors as variables. In this study, seven influential factors (W/B ratio, Water, Cement, Fly ash, Blast furnace slag, Curing temperature, and humidity) of papers opened for 10 years were collected at three conferences in order to know the various correlations among data and the tendency of data. The purpose of this paper is to estimate compressive strength more accurately by applying it to algorithm of the Deep learning.

Fiber reinforced concrete as a construction material has been widely used. Fibers, as the reinforced component, the physical properties and the distribution influence the engineering properties of the composite. To illustrate the engineering properties, fiber distribution and orientation are necessary. Steel fibers can be easily captured by X-ray, but it is difficult them to express being numerical because they don't show as perfect circular shape on the grinding face. To get the more exact information for this, the numerical method for the orientation and distribution of fibers have to be more elaborately. This paper presents a possible method which makes the calculate for orientation possible.

Curling is caused by the shrinkage difference between surface and bottom side of concrete, and the cracks can be occurred by vehicle load after curling. It is important to investigate and predict the curling behavior to minimize the quality defect of concrete due to the curling. Therefore, the experimental and analytical investigation was carried out.

Concrete can be used semi-permanently unless the steel is corroded. However, the concrete exposed to the marine environment is exposed to sea breeze, so chloride ions penetrate into the concrete and the steel is corroded accordingly. In order to solve these problems, there is a method of increasing the covering depth of the concrete and an application of the epoxy paint to the steel. In this study, the hydrotalcite type corrosion inhibitor was mixed with the concrete and the compressive strength, chloride diffusion coefficient and the corrosion properties of the steel were examined.

Recently, there has been an increasing interest in natural radioactive gas radon(Rn-222), the problem of indoor air quality pollution to worldwide. It has been scientifically proven to be hazardous to various diseases such as lung cancer and skin cancer if the human body is exposed to long-term accumulation of atomic nuclei due to the destruction of radon and alpha lines. Based on the indoor air quality control policy, this study is a basic experiment in the manufacture of a selective elimination function to containing radon adsorption and reduction of radon concentration, which is used to absorb radioactive isotopes such as phosphorus and radon in indoor environment.

Oyster shell is produce by shucking process in oyster farming in southern coast of Korea. In average, about 6.7kg of oyster shell is produced as an industrial waste for 1kg of oyster flesh, and even only in last year, it is estimated that about 150,000ton of oyster shell is produced. Oyster shell is light weighted and the strength characteristic of it is similar to send. We produced mortar test piece using grounded oyster shell powder according to Filler and Fiber. So I wanted to measure the strength and use it as a baseline for follow-up studies.

Performances such as retention, setting time and strength generation of mortar with phosphate-introduced chemical admixture, domestic and foreign admixtures are evaluated to find one that meets over 3 hours retention in extremly hot weather condition in this study.

This study investigated the drying shrinkage and compressive strength properties of mortar by the blaine of ferro-nickel slag powder to estimate the applicability of ferro-nickel slag powder for cement replacement materials. As a test result, the blaine of ferro-nickel slag powder increased, the compressive strength increased and the shrinkage rate decreased.

LEFC(Light Emotion Friendly Conceret) was developed in Korea with demands of esthentic requirements in line with the recent developmental trend of concrete technology. The LEFC is made by inserting transparent transparent rods, and this forms a heterogeneous structure in the concrete matrix causing the LEFC substrate to crack due low adhesion between the rod and the cement. In this study, as a way to strengthen the bonding to the rod inserted in the LEFC, high strength vinylon fibers of varying mixture ratios were applied and physical properties were tested accordingly. To study the effect of different spacing of the bars on the LEFC, physical property testing was conducted on respective specimens with two different diameters (5mm, 10mm) inserted in different intervals of spacing (10mm, 15mm, and 20mm).

This paper is to provide a method to prevent air loss of the concrete using reject ash based ternary blended aggregate due to absorption of AE agents by reject ash by adding AE agents into reject ash before mixing concrete. Test results indicate that air loss due to presence of reject ash in ternary blended aggregate can be recovered by over use of AE agents into aggregate directly before mixing.

Previous studies have confirmed the performance of pH reduction agents using liquid sodium phosphate based ammonium chloride as a pH reduction agent. In this study, the pH reduction performance considering economical and applicability as a practical stage and the property change analysis for the identification of the reaction mechanism of the pH reduction agent were carried out. As a result, the pH reduction performance at a low rate of the pH reducing agent was confirmed. The specific gravity of CaO decreased significantly after XRF analysis. It is also believed that this reduces the amount of Ca(OH)₂ produced and contributes to pH reduction.

The purpose of this study is to derive the optimum water absorbing curing time. It was found that the cement paste compressive strength was increased with the water absorbing ratio up to 40%, but the compressive strength was slightly lower when the catch level was over 50%. It is considered that the superfluous water did not react and remained in the inside of the specimen, causing microcracks in the inside due to the high temperature curing, resulting in a decrease in strength. Therefore, it is considered that the optimum catcher curing time for improving the strength through catcher curing is when the catcher reaches 40%.

In recent years, it has been urgently required to develop and study a product that adsorbs and reduces lardon gas due to the risk of lardon gas in Korea. Therefore, this study develops a board for adsorbing lardon gas into the inside and outside of the room. The thermal conductivity was measured in order to carry out an adiabatic test for satisfying the following conditions. Experimental level and factors were substituted with silica gel. In addition, silica gel was used by dry mixing and prewetting, and 10, 20, and 30% of cement was substituted for each. As a result of the test, the thermal conductivity decreased to 0.45 W/mK with increasing the amount of replacement, and reached a similar level when compared with diatomite.

Radon has been considered the greatest source of exposure within the total radiation exposure of the human body. xposure from radon, which exists in indoor air quality, lacks public perception, Radon, which exists anywhere on earth, is not regarded as a state of attention even if it is above the average level. Indoor radon exposure situations are not intentionally introduced, and essentially the attention and responsibilities of radon exposures are assumed to be in indoor occupants. So, these are caused by common uranium and thorium scattering on Earth, and are brought into the building by fine cracks or exposed indicators of the buildings. Therefore, this study aims to reduce the risk of radon rays and reduce radon, which induces diseases caused by breathing in the body of indoor air pollutants and emitting diseases by emitting alpha rays from the radon gas.

In this study, the change of composition of cement hardened at high temperature through XRD was observed. The specimen was made of cement paste and the heating rate condition was applied at rapid thermal annealing (10.0℃ / min). The decrease of calcium hydroxide was not confirmed, but the calcium carbonate tended to be impossible or decreased after 800℃. Calcium silicate and larnite were observed to increase with increasing temperature. It is considered that silicic acid, which is a stable structure due to the decomposition of calcium silicate, is changed into a phase such as lime.

According to the experimental results of researchers recently seen, there is a case where a significant difference between data of several reports and measured powder is detected, and concrete examination on this is necessary. In this study, we compare the actual powdered degree of powdered aid on the report against 20 OPCs that are actually being brought into the raw concrete plant, and the OPC powder also influences the difference of OPC powder's strength characteristics on hardened mortar Was analyzed. As a result of the analysis, doubts were raised on the reliability of the OPC powder degree described on the certificate, and the bending and compressive strength tended to increase as the degree of fineness of the measured OPC increased.

The combined waterproofing method is an excellent method to overcome the disadvantages of the single waterproofing method by composing two or more materials to complement each other, but it is a method that can cause defects such as separation and peeling between materials due to the heterogeneity of the applied two materials. In order to improve this, in this study, we aimed to develop a technology for inducing chemical unification between materials through a urea reaction with a coating material applied on the lower side by laminating a nonwoven fabric treated with a modified amine on the back surface of the sheet material, The adhesion performance test was carried out with the presence or absence of denatured amine treated nonwovens as variables. As a result of the test, it was confirmed that the adhesion performance of the specimen to which the modified amin - treated nonwoven fabric was applied was improved by about 60% or more as compared with the specimens not having the denatured amine treated specimen.

Polyurethane coating materials are widely used in waterproofing construction because they ensure easy workability and high performance mechanical properties, and such polyurethane coating materials are in various mixture ratios. This study carried out a test to determine the basic physical property changes of polyurethane coating material based on the amount of charcoal additives to. The results showed that he tensile strength was found to be 3.1 N / ㎟ when the charcoal amount was at 2%, displaying the highest performance rate.

As the building is becomes bigger and larger, it can lead to big damage in case of fire. Also, tunnel, machine room and underground joint are spaces that can cause high temperature fire above 1,350℃ in case of fire. Therefore, a refractory material is need that can be withstand in high temperatures for long time. One side, the composition of oyster shell is CaCO₃ of 90% or more. It is expected that it will be possible to use it as a high calcium natural material which is the material of the refractory board. According to, Study on bending, compressive strength of mortar according to temperature and heating time change using classified oyster shell as aggregate.

In this study, the spalling properties of Polypropylene reinforced concrete were evaluated by the restrained ring-type test. As a result of the experiment with the fiber mixture ratio set at 0, 0.15 vol.%, The PP fiber reinforced specimen showed lower water vapor pressure as a whole than the Plain specimen, but the restraint stress was measured to be higher. This is thought to be due to the fact that higher thermal stresses were applied in the PP fiber reinforced test specimen.

This study investigates the effect of improving the heat resistance performance when carbon fiber is mixed in the polyurea coating material. A tensile strength test method was carried out with the carbon fiber mixed polyurea specimens at an interval of 7, 14, and 21 days after heat treatment at 140±2℃. The test results showed that there was a significant decrease in the tensile strength performance. While the elongation and tensile performance decreased greatly, it was confirmed nevertheless the overall performance was maintained. This study proposes that mixing carbon fiber to the polyurea resin can effectively secure long-term heat resistance, thereby solving the problem of deterioration of physical properties caused by exposure to ultraviolet rays.

Concrete properties alone cannot provide satisfactory waterproof performance because concrete can generate cracks due to possible problems in design, construction and curing process, and various environmental factors. Therefore, concrete structures require installing waterproofing layers for concrete protection and various types of construction methods are currently being applied. The purpose of this study is to investigate the concrete strength changes when waterproofing admixtures are mixed into the concrete. The results of flexural strength testing confirmed that the initial strength of concrete specimens with the admixtures was lower than that of the concrete specimen without the admixture based on different curing periods.

The combined waterproofing technique, which forms the waterproofing layer of two or more substances, is characterized by forming a waterproof layer, which is characterized by the formation of waterproof layers and the thickness of the waterproofing layer is inherently formed. In this study, it is intended to verify the integrity of the material through the manufacture of materials for special purpose waterproofing methods, primarily for the manufacture of composite waterproofing materials and composite waterproofing methods using cement materials and materials.

This paper examines the efficiency of the application of conventional and insulated gang forms for curing and protection of concrete by comparing the amount of electric energy required therefor. In addition, a thermal vision camera was used to identify heat loss from surfaces of the gang forms after each placement of concrete. Experimental results, show that the heat loss at the submerged temperature was large at the submerged surface due to the large calorific value at the surface of the mold. The insulated gang form had some heat loss in the horizontal bars. In the case of adiabatic reforming, the pattern shows a constant calorific value over time. In conclusion, the insulation performance is better than that of general gang form.

Generally, a lot of reinforcements are used in nuclear power plant concrete structures in order to improve the structural safety, but it may cause several potential problems due to the overcrowded reinforcement, such as the degradation of concrete quality, the construction delay and the increase of construction cost. In order to resolve these problems, structural test researches and code change studies on using high-strength reinforcement (Gr.80) in unclear power plant structures are under way, and there is good progress in code change of ASM BPVC.III.2 and ACI 349. This purpose of this study is to review the code change status ASM BPVC.III.2, ACI 349 under way to use the high-strength reinforcement in nuclear power plant structures. Also I will introduce the design optimization of NPP structures with high-strength reinforcements in order to maximize the effect and minimize the problem when using the high-strength reinforcements in NPP structures.

This technology employs a method of forming a single-ply PLUS waterproofing sheet layer comprised of applying a single-ply synthetic polymer layer on a vibrating structure (steel frame, RC) or an inclined surface by using a T joint lap-filling coil and an embedded metal coated sheet. The T - joint reinforcing lap-filling coil was used to block the ingress channel of the rainwater by applying the material in the vulnerable area where the three sides of the waterproof sheet overlapped. Conventional waterproofing techniques have a problem in that the waterproof sheet is pierced because the end portion of the waterproof sheet applied to the vertical portion is fixed by a nail, and the sealant applied to the end portion of the sheet cannot easily secure long-term waterproof durability due to the influence of the external environment. Therefore, the developed technology secured the waterproof durability against the vertical part by using the embedded metal sheet. In addition, automatic hot-air fusing is used to improve the quality of waterproof construction and point fixation method using fixed hardware. This is a technology that is not significantly restricted in the high degradation level regions of domestic waterproof construction environments in Korea such as low-temperature environment, wet floor.

New waterproofing technologies have emerged in the field of building waterproofing due to the recent diversification of the size and type of structures, the enhancement of required performance, and the diversification of new technologies (such as materials and methods)(Sheet waterproofing material, coating waterproofing material) is reduced, and composite waterproofing materials that utilize mutual benefits are widely used by compounding them (sheet+coating film, coating film+sheet). However, it is true that there is no evaluation method that can verify these composite waterproof materials, which is the most widely used at present, but the KS standard only specifies tests for individual materials However, there is a situation in which the countermeasures without a test method for composite waterproofing become sudden.

Due to the recent depletion of natural resources and global warming, a passive house type building exterior system has been developed and applied. For this purpose, we developed a building exterior thermal resistance performance evaluation system and verify the feasibility of this system for evaluation of passive house building system.

This research aimed to analyze the fundamental properties of cement mortar accompanying the change of the solid contents of the maintenance type PC water reducing agent. As a result of the experiment, it was found that the properties of fresh mortar show a tendency to decrease as the solid contents decreases in the case of flow and air contents, and the decrease width with time is small. It was found that the compressive strength of the hardened mortar has almost no difference due to the change of the solid fraction.

In this study, the tensile properties of mono and hybrid fiber reinforced cement-based composite according to fiber blending ratio under the high strain rate was evaluated. Experimental results, the HSF1.5PVA0.5 shown the highest tensile strength because the PVA fiber suppressed the micro cracks in the matrix around the hooked steel fiber and improved the pull-out resistance of hooked steel fiber. Thus, DIF of strain capacity and fracture toughness of HSF1.5PVA were greatly improved. Also, the fracture toughness was greatly improved because the tensile stress was slowly decreased after the peak stress by improvement of the pull-out resistance of hooked steel fiber at strain rate 101/s.

It is known that physical and chemical changes of cement hydrates cause problems in the volume stability of concrete. In order to overcome these problems, there is a growing interest in research on mixing technology of cement-based materials and nanomaterials. Among the nanomaterials, carbon nanotubes (CNTs) are attracting attention due to their excellent mechanical properties. The CNTs are made of cylindrically shaped graphene sheets. According to the number of sheets, single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) are classified. Although the SWCNT has superior mechanical properties, the research using MWCNT is vigorous due to the difficulty of marketability and manufacturing, but the research using SWCNT is insufficient. In this study, we investigate the effect of SWCNT on the formation of hydrate of cement paste by observing the microstructure of broken cement paste after measuring the flexural strength of cement paste with SWCNT dispersion.

This tests examined the effectiveness of bacteria slime on the chloride ion penetration resistance of cement mortar. Test results exhibited that the chloride ion penetration depth of mortars including 5% expanded vermiculite immobilizing bacteria was 17% smaller than that of the control mortar without expanded vermiculite.

Graphene is a nanomaterial and is known to have very high mechanical strength, thermal and electrical properties. However, graphene is known to be difficult to disperse among carbon-based materials due to van der Waals force. In this study, to solve the dispersion problem of graphene nanoplatelet, oxidized graphene nanoplatelet was prepared by oxidizing GNP in nitric acid. The prepared GO was dispersed in ethanol and distilled water before incorporation into the epoxy paint to confirm dispersibility. In addition, GNP/Epoxy and GO/Epoxy tensile specimens were prepared by mixing GNP and GO at 0.1, 0.3, 0.5 and 1.0 wt.% In epoxy coatings and tensile stress-strain characteristics were investigated.

Borosilicate glass was incorporated to improve the neutron shielding capability of concrete. Boron is a typical neutron shielding material, and it is contained in borosilicate glass. However, borosilicate glass causes alkali-silica reaction, which damages the concrete. Therefore, studied to reduce the expansion due to alkali-silica reaction and to improve the neuton shielding capability. The measurement of the expansion due to the alkali-silica reaction was based on ASTM C 1260. Experimental results show that the expansion due to alkali-silica reaction is reduced when borosilicate glass powder incorporated. In addition, the neutron shielding capability was significantly improved when the fine aggregate replaced with borosilicate glass.

This tests examined bond stress-slip relationship of V-ties embedded into concrete as a supplementary lateral reinforcement proposed for ductility of concrete flexural members. The different leg shapes of V-ties were prepared as a test parameter. The V-tie with pressed end-legs exhibited 28% higher bond strength than the conventional V-ties, whereas bond stress-slip curves were insignificantly affected by the embedment length of V-ties.

Recently, researches on controlled low strength materials using coal ashes have been actively conducted in Korea. Controlled Low Strength Material by using a large amount of Coal Ashes, which is a by-product of the industry, will solve the environmental problems caused by coal ash as well as economic formulation. In this paper, the compressive strength and flow of the CLSM binder were investigated in order to select the optimum mixing ratio.

As the use of cement increases with the development of modern society along with the increase of buildings, environmental pollution intensifies and researches on industrial byproducts are continuing. Research on blast furnace slag and fly ash as industrial byproducts is increasing, and research on industrial byproducts such as polysilicon sludge and paper ash used in this study is increasing. Blast furnace slag, which is one of the industrial byproducts, has been widely studied as a material used with cement. However, in this study, we fabricated lightweight matrix of polysilicon sludge and paper ash replaced based on blast furnace slag, and performed SEM analysis.

The paper is to investigate the effect of spreading of various kinds of oils on resistance to chloride attack of the normal strength concrete. Resistance to chloride attack was measured for 32 weeks and six different kinds of oils ere used. Test results indicated that resistance to chloride attack was improved in order of DSP, BD, ERBD and ERCO compared with that of Plain mixture due to filling effect of capillary pore by the use of oil.

The purpose of this study is to investigate the effect of tile adhesion failure due to weak adhesion with concrete admixture (FA, SP) on walls. The test specimens were divided into four types : (1) OPC 100% (2) OPC 80%+FA 20% (3) OPC 80%+SP 20% (4) OPC 60%+SP 40%, each adhered on a 650 × 650mm wall with 200mm thickness capable of attaching two insulation tiles (300 × 600mm). The tests were carried out on the four types of walls by mortar bedding application method, and after 4 weeks of curing period, adhesion strength test was carried out. The adhesion strength difference was investigated between the concrete wall with added admixture (FA, SP) and general concrete wall.

In this research, the blast-furnace slag powder using the hydrometer also attempted to analysis the influence factor due to the temperature change of water and sample, and the number of upside down turns at the time of rapid evaluation. As a result, the influence of the number of turn was not large, but was the temperature of the water and sample are greatly affected.

In this study, the adequacy evaluation of limestone for exterior use is presented. Major flaws of limestone for exterior use are reviewed. In addition, freezing-thawing test of the limestone specimens were performed. As a result, the limestone specimens was damaged by the freezing and thawing action for 300 cycle.

There is some recognition that Decoration Wood-based Flooring Board in Korea is a material that inhibits the heat transfer from the substrate to the room. There is a lack of substantial research literature on the surface heat transfer and condition of Decoration Wood-based Flooring Board, which is insufficient to deal with false perceptions. In this study, the purpose of this study is to analyze the surface heat transfer characteristics of Decoration Wood-based Flooring Board and to obtain basic data to cope with recognition.

Although the application period of hot weather concrete in our country is two months of July~August which is relatively short, many problems in various aspects such as generation of plastic/dry contraction cracks and cold joints can be caused unless proper quality control measures are established at this time. Therefore, this study compared the temperature history of the placed concrete by applying a mono white and aluminum-deposited bubble sheet developed with surface coating curing materials for surface exposure and summer to an actually constructed apartment slab. The analysis result showed that the mono white bubble sheet is the best method.

Many problems in various aspects such as generation of plastic/dry contraction cracks and cold joints can be caused unless proper quality control measures are established in hot weather circumstances. Therefore, this study aimed to compare the crack patterns of concrete by applying a change in 3 surface curing methods such as a mono aluminum-deposited bubble sheet developed to reduce the temperature and cracks through reflection of heat in summer and a PE film and a surface exposure used generally to an actually constructed apartment slab. The study result confirmed that the best concrete crack reduction effect can be obtained with a mono aluminum-deposited bubble sheet.

The beam-column connection using high-strength GFRP bars exhibited a comparable flexural strength but brittle failure mode, when compared with those of connection using high-strength steel reinforcement.

In order to improve the constructability of tall building construction, there is increasing needs to derive the design output by performing construction engineering at the design phase. It contributes to minimizing wastes such as design changes and reworks as well as improving project performance. Therefore, in this study, we analyzed the application period and participants for engineering tasks derived from a previous study, and then regrouped to efficiently reflect them at the design phase. Considering similarity of application period and attributes, the existing 22 engineering tasks, which were classified into 5 factors, were reclassified into 13 groups. The results of this study can be used as basic data for efficient construction engineering execution at the design phase.

This study analyzed the performance of new construction technology in construction site. The main results are as follows. First, 83.6% of the new technologies developed by SMEs(joint development by large enterprises) account for the majority. Second, new construction technology is mainly applied to construction and civil engineering, but it is mainly applied to four major types of work(waterproofing, soil and foundation, reinforced concrete, bridge). Third, the number of on-site applications with a construction value of less than 500 million accounted for 89.5% of the total, which indicates that new construction techniques are mainly applied to small-scale construction.

Some of the information created during the design phase of an New NPP life cycle is useful only for the execution of the construction phase; however, much of the information greatly impacts the longer-term operational phase. To most make use of design and construction information produced by data based design system during the construction and operation phase, This research is identified controlled data and drawn design information of controlled equipment from documents generated during the life-cycle stages. This study aimed to analyze related documents to assure traceability of controlled equipment from design phase through O&M and then suggested DB(Data Base) based control method on technical information of major equipment throughout nuclear power plant lifecycle.

Even large construction projects of nuclear power plant construction and production data is increasing dramatically due to the introduction of ICT technologies, such as 3D scanning technology, wireless communication technology, virtual construction management technology. There are various attributes and types of data to be produced and managed because the documents generated by the contract method are different from the cost processing method. According to the requirements of the international nuclear bid, it is required to present the cost that is calculated based on resource quantity. This research considers ways in which the cost management based on the resource quantity.

Korean government is trying to adopt 'CM at Risk(CMR)' method to solve some problems of traditional project delivery method such as cost increase, delay, low quality. Pre-construction service(PCS) is a project management methodology of CMR and BIM is the best tool for efficient PCS execution. PCS is consisted of several main items such as Target costing, Cost trending, GMP, Design optimization, Constructability review and Productivity. The purpose of this research is to analyse contractor's PCS application case result and to find improvement items.

As buildings take on more advanced features, mechanical facilities of buildings are accounting for increasingly greater significance in building construction projects. However, mechanical facility designers are forced to be content with design service fees that do not properly compensate their excessive workload, with lowest-bid-first tendering practices compounding their economic woes. In relation to this, this Study aims to offer suggestions for better standards for compensation of design service for mechanical facilities of buildings, highlighting five key suggestions in consideration of relatively small size of work and unmatched long duration of work.

In response to the economic depression, the demand for fixed rent income has increased according to the easing construction regulations. it caused indiscriminated investment to stakeholders. This leads to oversupply in the multi-family Housing market and increases unsold housing and vacancy rates except specific area such as Gangnam-gu.In order to solve this issue, although studies on the optimization price of apartment houses has been conducted, the study is insufficient regarding on residential officetel. Therefore, the objective is to suggest a basic study on optimal price estimation model development by using probabilistic forecasting method in planning phase. To achieve the objective, first, variables are defined such as expenses, financial costs, income, etc. Second, causal loop diagram is suggested. Third, basic optimization prices estimation model is developed. In the future, this study can be used as one of decision making tools in planning phase of officetel development projects.

In this research, the density value of the turbid solution is measured by using the principle of inexpensive but easy Hydrometer method for cement delivered to the actual raw concrete plant, By analyzing the correlation of powder aid, we will try to present a scheme that can be utilized as a method of acquisition acquisition inspection. As a result of the analysis, it was found that there was a large difference between the measured powders assisted with cement powder on the report, and the correlation with the actually measured powder aid Hydrometer density value was good. Therefore, using the method of Fig. 3, it was possible to know that the degree of powder quality of cement delivered to the raw concrete factory can be evaluated quickly and utilized at the time of argument inspection.

The number of human accidents in the construction industry is increasing every year, and it constitute the highest percentage among industry. This means that activities performed to prevent safety accidents in the country are not efficient to reduce the rate of accidents in the construction industry. In order to solve this issue, research has been conducted from various perspectives. But, research regarding to quantification model of human accidents is insufficient. the objective of this study is to conduct a basic study on quantification model development of human accidents. To achieve the objective, first, Cause of accident is defined the through literature review. Second, a basic statistic analysis is conducted to determine the characteristics of the accident causes. Third, the analysis is conducted after dividing into four categories : accumulate rate, season, total construction cost, and location. In the future, this study can be used as a reference for developing the safety management checklist for safety management in construction site and development of prediction models of human accident.

Large spatial construction needs to consider various construction management factors through the construction guide, including high-tech roofing works for creating large space without columns and erecting large spatial structure. However, the domestic large spatial construction relies on overseas construction technologies due to the lack of construction guide of large spatial construction and experience in similar type of project. To improve the problem, we deduced principal items of construction management considering characteristics of large spatial construction as a preliminary study for developing a construction guide.

The Configuration Management(CM) of Nuclear Power Plant(NPP) is an activity that maintains consistency among the design requirement, facility configuration information and physical configuration. It is a systematic approach to performing various engineering tasks such as change management by identifying, documenting the characteristics of plant Structures, Systems and Component(SSC). The first activity that should be performed the configuration baseline setting at the start of project. The configuration baseline of the NPP construction phase is the status of the SSC of the plant at a specified process and time, and the actual configuration changes depending on the condition of plant. In this paper, I have studied the current status of configuration baseline used in the software industry and general plant industry, method of establishment for the configuration baseline which was first applied to the construction of NPP.

In this paper, we classify 3D printer technologies which are becoming a recent issue, and analyzed the features and limitations of the technology. As a result, we can see that there is no 3D printer technology that can produce a completely free-curved architectural structure. In order to construct a completely free-curved architectural structure with a 3D printer, it is necessary to draw up a new concept technique that complements the drawbacks of the two methods.

In case of developing a guide-rail type window cleaning robot, only the first prototype has been developed. In this study, it was considered that the size and the load of the window cleaning robot was not optimized, and through the structural analysis of the self-weight of the window cleaning robot, the stress concentration area was derived and the concentrated stress was quantified. Analysis showed that the upper rail shaft had a bending stress of 9.964Mpa and the bolt had a shear stress of 19.544Mpa. The results of this study will be used as basic data for designing future prototypes.

The purpose of this paper is to examine a reasonable share of cost in the apartment remodeling projects. Therefore, the case model of remodeling apartment was made up and then the rate of return by method of floor area change rate, method of proportion, method of investment earnings rate and method of proportion reflected business contribution were estimated. Consequently, the model by the method of proportion reflected business contribution presented 20.6% of rate in all apartment units.

The current study assumed a condition in which concrete curing was not completed correctly in the winter, in order to analyze the effect of changes in early low-temperatures in early-frost damage depth. As a result, lower external temperature early on after depositing the concrete greatly reduced the temperature in the upper parts of the concrete, and it delayed the time during which the concrete temperature restored. In addition, for early-frost damages, lower early temperature increased the expansion of frozen water, which in turn relaxes the concrete structures and increases the absorption rate, ultimately extending the depth of early-frost damage.

Recently, bathroom tile defects in households are occurring more frequently. Until now, the destructive investigation method has been required to analyze tile defects. This study proposes a non-destructive using a thermal emission camera imaging as a possibly more precise method of investigating tile failure compared to previous existing methods.

In this study, a survey was conducted to investigate the environmental degradation factors of specific areas in residential apartment underground structures an'd the required performance attributes for waterproofing material. Based on the survey, it was concluded that joint displacement of concrete is the highest cause for problems, and the required performance was determined to high wet surface adhesion performance for waterproofing materials.

Existing studies highlights the problems about the negative-side waterproofing design of apartment complex underground structures. This study suggests the alternatives for waterproof design construction details of as a solution, and a review on the applicability of this new construction design details through a mock-up construction is provided.

Residential apartment underground structures are being utilized for many purposes such as parking lots, community centers, fitness centers, etc. for efficient use of space. However, there are increasing problems of leakage due to various environmental and deterioration conditions. This paper proposes the development of an information network system which can serve as a base to provide solutions, alternatives and technical information for leakage prevention and effective design at the beginning of the construction stage.

Current domestic waterproofing market in Korea mainly uses single-ply waterproofing materials comprised of coatings or waterproof sheets and two or more-ply composite waterproofing methods. In order to evaluate these types of composite waterproofing systems, a new test equipment and method that incorporates various deterioration conditions (joint displacement, chemical exposure, water pressure etc) was developed. In a comparison testing, the results showed that flexible type materials have higher response performance towards joint displacement than the hardened material. Furthermore, the importance of securing the stability of the waterproofing method in the vulnerable over-lap joint areas of waterproofing sheets is emphasized.

An analysis of the current water leak status of understand structure (underground parking lots, staircases, plumbing systems, water reservoirs, etc.) of multi-family housing in South Korea shows that water leaks are found from cracks in all areas of the underground structure caused by the degradation environment (water pressure by underground water, humidity, temperature, earth pressure, soil behaviour and vibration, etc.), which result in various problems, including mold, malodour, debonding of finishing materials, exfoliation, breakout, water leaks in electrical boxes, efflorescence, sedimentation of calcium hydroxide, decoloration, rusting, damages and pollution among others. Therefore, this study aims to analyse the current status of water leaks in underground structure and use the results as the basic data for developing a standard guideline for water leaks and maintenance by parts of the underground structure of multi-family housing.

In this study, various materials such as epoxy material, urethane material, cement material, and acrylic material are used to solve the water leakage occurring in underground structures. However, in the reality that the durability is insufficient and the effect is insufficient, it is aimed to improve the repairing effect by using cement and acrylics in combination. As a first study, we tried to verify the performance of improve the performance by checking the product properties according to the composition ratio of polyacrylic resin. Polyacrylic resin is evaluated in three different composition ratios. When the material is selected for polyacrylic resin, it is applied to the field to understand the maintenance effect and durability.

Recently, there has been a growing interest in the development of non-sintered binder to reduce CO2 emissions from the cement clinker manufacturing process and a number of studies have been conducted on fly ashes as an industrial by-product. However, in order to utilize fly ashes as a non-sintered binder, it is necessary to solve problems such as safety issues and economical efficiency due to use of an alkali activator. This study evaluates the material properties and compressive strength characteristics of three types of circulating fluidized bed boiler ashes. As a result, it was confirmed that the characteristics of each binder vary depending on the location of the power plant and the types of raw materials. In addition, it has been confirmed that the fluidized bed boiler ash shows a high compressive strength and can be used sufficiently as an non-sintered binder.

In this study, the inductor heating which is confined to the metal processing is used by demolition technology in reinforced concrete. And, the purpose is the verification of realization for this technology. Using the inductor heating device, the temperature rising is measured depending on the difference of the generating capacity. And, the demolition of reinforced concrete is evaluated by the vulnerability of concrete due to the inductor heating of rebar in reinforced concrete.

This study aims to achieve an enhancement in the quality of high strength concrete through a reduction in autogenous shrinkage by supplying the moisture needed for hydration through recycled aggregates that retain high amounts of moisture. The result showed that, moisture supply increased with the higher replacement rate, autogenous shrinkage dropped by up to 60 percent. Also, compressive strength was increased by up to 10 percent.