• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.133-144
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• 2006

In order to catch out such Bond Strength, the preceding researchers had ever examined the Bond Strength of FRP Plate through their experimentations by setting up of various fluent. However, since the experiment for research on such Bond Strength takes much of expenditure for equipment structure and time-consuming, also difficult to carry out, it is conducting limitedly. This Study purposes to develop the most suitable Artificial Neural Network Model by application of various Neural Network Model and Algorithm to the adhering experiment data of the preceding researchers. Output Layer of Artificial Neural Network Model, and Input Layer of Bond Strength were performed the learning by selection as the variable of the thickness, width, adhered length, the modulus of elasticity, tensile strength, and the compressive strength of concrete, tensile strength, width, respectively. The developed Artificial Neural Network Model has applied Back-Propagation, and its error was learnt to be converged within the range of 0.001. Besides, the process for generalization has dissolved the problem of Over-Fitting in the way of more generalized method by introduction of Bayesian Technique. The verification on the developed Model was executed by comparison with the resulted value of Bond Strength made by the other preceding researchers which was never been utilized to the learning as yet.

• Journal of the Korea Institute of Building Construction
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• v.6 no.3 s.21
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• pp.91-97
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• 2006

Sewage facilities are positively necessary for environment improvement such as rainwater removal, sewage disposal, preservation of the qualify of water and health of the citizens in present-day. Meanwhile, a deterioration of the concrete sewer pipe is increasing rapidly due to the chemical and physical attack and especially biochemical attack that is to say biodeterioration. In this study, researches for the development of antibiotics and antimicrobial concrete were conducted to reduce biochemical corrosion of sewage concrete. First of all, desired performance, such as watertightness, antibiosis, homogeneity, workability and harmlessness, was proposed and performance of antibiotics and antimicrobial concrete were evaluated by them. And developed antimicrobial concrete was applied to actual construction field. As results of this study, dispersibility and antibiosis of liquid antibiotics superior to powdery antibiotics. Antibiosis of antimicrobial concrete was verified, and amount of elution of harmful and effective ingredients was little. In workability, setting time of antimicrobial concrete was delayed. Compressive strength and resistance to carbonation of antimicrobial concrete were more increased than ordinary concrete. Finally, as there were no problems in quality and construction progress of antimicrobial concrete produced in plant, applicability of antimicrobial concrete to actual construction field was verified.

• Advances in concrete construction
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• v.6 no.3
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• pp.311-322
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• 2018

This paper presents an experimental investigation on the performance of concrete with and without glass powder (GP) subjected to elevated temperatures. Mechanical and physicochemical properties of concretes were studied at both ambient and high temperatures. One of the major environmental concerns is disposal or recycling of the waste materials. However, a high volume of the industrial production has generated a considerable amount of waste materials which have a number of adverse impacts on the environment. Further, use of glass or by-products in concrete production has advantages for improving some or all of the concrete properties. The economic incentives and environmental benefits in terms of reduced carbon footprint are also the reason for using wastes in concrete. The occurrence of spalling, compressive strength, mass loss, chemical composition, crystalline phase, and thermal analysis of CPG before and after exposure to various temperatures (20, 200, 400, and $600^{\circ}C$) were comprehensively investigated. The results indicated that, the critical temperature range of CPG was between $400^{\circ}C$ and $600^{\circ}C$.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.975-978
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• 2008

To strengthen the technological competitiveness of the construction market in Korea, researches have been performed to replace the prescriptive design codes (PD) to the performance-based ones (PBD). As one of the basic requirements for PBDs, development of the optimized concrete material models for domestic applications have been tried by comparing and verifying the pre-existing models with the observations and quality evaluations of ready mixed concretes that are used in the domestic market. This paper shows the summary of the present state of the research progress in the areas of compressive strength and elastic modulus.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.49-52
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• 2008

The present study was to develop a dry PFB method similar to the existing gypsum board construction method in order to apply the existing wet PFB method that uses fire-resistant adhesive. It was found that the existing wet method can produce concrete compressive strength of 80MPa and fire resistance of 3 hours with 30mm PF boards. The goal of development in this study was fire resistance of 3 hours through dry construction of 15mm fire-resistant boards. 1. Improved PF board was prepared by adding inorganic fiber to existing board and using aggregate with grain size of 3mm or less. Molding was done at temperature higher than that for existing PF board molding. While wet curing is used for existing PF boards, this study used dry curing in order to enhance heat insulation performance. 2. According to the results of fire resistance test, when the dry PF method was applied, the temperature of the main reinforcing bar was 116℃ in 15mm, 103.8℃ in 20mm, and 94℃ in 25mm, and these results satisfied the current standards for fire resistance control presented by the Ministry of Land, Transport and Maritime Affairs. When a 3-hour fire resistance test was performed and the external properties of the specimen were examined, the outermost gypsum board hardly remained and internal PF board maintained its form without thermal strain.

• Journal of the Korean GEO-environmental Society
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• v.15 no.2
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• pp.17-25
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• 2014

In the present study, it were performed an unconfined compression test and a field applicability test according to a mixed ratio of SS, soil type and curing period to analyze strength and deformation characteristic in order to evaluate engineering characteristics of soil mixed pavements using the eco-friendly soil stabilizer (SS). The test results revealed that SS mixed soil shows fast strength development at the initial curing time while 28-day strength amounted for 97% of the final strength. Furthermore, coarse-grained dredged sand (DS) and weathered granitic soil (WGS) have a larger ratio of deformation coefficient with respect to unconfined compressive strength than fine-grained dredged clay (DC) and organic soil (OS). Moreover, a comparison test between natural and forced drying conditions was conducted and test result showed 54% to 67% of strength degradation while having 55% to 63% of strength degradation in the freezing and thawing test result. Finally, a repeated loading test result showed that DS experiences up to 35% of strength reduction compared to initial strength under 10,000 times loading in maximum. Thus, it was validated that an appropriate amount of fine-grained sand is necessary to secure resistance capability to repeated loading.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.35-43
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• 2022

The aim of this work was to a comparative review the performance of high calcium silicate cement (HSCSC) and that of ordinary Portland cement(OPC) and blast furnace slag cement(S/C). The result of the compressive test confirmed that the compressive strength development rate of high calcium silicate cement concrete at the age of 3 days was 73.6% that of ordinary Portland cement concrete. However, at the age of 28 days, the strength development rate of high calcium silicate cement increased to about 107.0% compared to ordinary Portland cement. In addition, the test of the chloride ion penetration resistance of concrete showed that at the age of 28 days, the passed charge decreased by 73.4% and 93.0%, respectively, in blast furnace slag cement and high calcium silicate cement compared to ordinary Portland cement, and at the age of 56 days, it decreased by 79.1% and 98.3%, exhibiting excellent resistance to chloride ion penetration. In particular, it was confirmed that the rate of decrease in the passed charge with age was higher in high calcium silicate cement than in ordinary Portland cement and blast furnace slag cement.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.2
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• pp.185-191
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• 2017

The objective of this paper is to investigate the effect of waste refractory powder(WRP) and desulfurization gypsum(FGD) as activators on the flow properties and the strength development of high volume blast furnace slag mortar incorporating illite(BSM) having adsorption and deodorization. To fabricate the BSMs with 60% of W/B, blast furnace slag are incorporated with 45% and 65%, respectively. WRP and FGD are substituted from 5 to 10%. Test results indicate that the flow is decreased with increase of WRP and FGD, while increase of WRP and FGD enhance the compressive strength due to accelerated reaction of blast furnace slag, The use of illite results in a decrease of compressive strength. pH has increasing tendency until 7days, while it has reduction. In this paper, optimal dosages of WRP and FGD are believed to be around 5% each.

• Journal of the Korea Institute of Building Construction
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• v.17 no.4
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• pp.313-320
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• 2017

Flue gas desulfurization gypsum(FDG) is produced when removing sulfur oxides from combustion gas generated by coal power plant. However, the recycling of FDG is still limited to the certain purposes. In order to expand the possible application of FDG, this study aims to utilize FDG as an activator for ground granulated blast furnace slag. FDG produced by dry- and wet-process were used for the experiments. Slag paste specimens were produced by mixing with deionized water and simulated pore solution, and the role of FDG as an activator for blast furnace slag was evaluated using hydration study by XRD analysis and compressive strength development. According to the results, dry-type FDG was found to work as an activator for blast furnace slag without the presence of soluble alkalis. However, wet-type FDG needs assistance by soluble alkalis in order to work as an activator for blast furnace slag. It was also found that the substitution of dry- and wet-type FDG into blast furnace slag can increase the 28 day compressive strength of slag paste. It is expected that efficient and economical recycling of FDG will be possible if quantitative analysis of strength enhancement according to substitution rate of both dry- and wet-type FDG.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.15 no.3
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• pp.83-91
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• 2009

It is very difficult to export the fresh agricultural products to long distance countries such as USA and EU without any damage. Fresh products exporting would overcome very severe conditions such as hot and cold weather changes, heavy vibrations with rolling and pitching during the target distribution period, therefore, the packaging needs the immobility of products in the container and the keeping its quality by packaging materials or methods under any surrounding environments, especially. The physical strength of outer box should be designated according to its own characteristics for agricultural product packaging. Packaging dimension which would be fit to standard pallet is also very important factor to reduce the distribution cost. There have been many agricultural products researches for export packaging to the USA so far. However they have never got desirable results which enough to apply it in real. The main purpose of this research is to develop optimum compressive strength and optimum dimension of corrugated fiberboard box which would be used to USA export packaging of fresh melon as well as Japan.