• Journal of the Korean Recycled Construction Resources Institute
• /
• v.11 no.4
• /
• pp.493-500
• /
• 2023

The use of TiO₂ photocatalyst in the production of concrete blocks for the purpose of nitrogen oxide reduction is an issue of controversy due to the conflicting evidence on its effectiveness. Efforts have been made to reduce the level of nitrogen oxides in the environment by using of titanium dioxide (TiO₂). This study examined the effect of incorporating activated carbon into concrete blocks on the reduction of nitrogen oxides released into the atmosphere and the durability of the blocks. The efficiency of photocatalyst was enhanced through the addition of a surrounding conductive substance. The addition of activated carbon resulted in a significant increase in the electrical conductivity of photocatalytic blocks and improved durability. The cement mixture using 5 % TiO₂ and 15 % activated carbon exhibited the optimal mixing ratio for the purpose of nitrogen oxide removal. The effect of the addition of conductive carbon to the photocatalytic blocks was discussed with the results of conductivity, flexural and comprssive strength and nitrogen oxide removal test. The relationship between the addition of conductive carbon to the photocatalytic blocks and its resulting effects have been studied by several tests, including conductivity, flexural and compressive strength, and nitrogen oxide removal.

• Journal of Korea Society of Industrial Information Systems
• /
• v.28 no.6
• /
• pp.45-52
• /
• 2023

Recently, as the importance of walking in daily life has been emphasized, projects to guarantee walking rights and create a pedestrian environment are being promoted throughout the region. In previous studies, a pedestrian environment assessment was conducted using Jeonju-si road images, and an image comparison pair data set was constructed. However, data sets expressed in numbers have difficulty in generalizing the judgment criteria of pedestrian environment assessors or visually identifying the pedestrian environment preferred by pedestrians. Therefore, this study proposes a method to interpret the results of the pedestrian environment assessment through data visualization by building a web application. According to the semantic segmentation result of analyzing the walking environment components that affect pedestrian environment assessors, it was confirmed that pedestrians did not prefer environments with a lot of "earth" and "grass," and preferred environments with "signboards" and "sidewalks." The proposed study is expected to identify and analyze the results randomly selected by participants in the future pedestrian environment evaluation, and believed that more improved accuracy can be obtained by pre-processing the data purification process.

• Journal of Environmental Impact Assessment
• /
• v.24 no.1
• /
• pp.16-34
• /
• 2015

Impervious covers(IC) are artificial structures, such as driveways, sidewalks, building's roofs, and parking lots, through which water cannot infiltrate into the soil. IC is an environmental concern because the pavement materials seal the soil surface, decreasing rainwater infiltration and natural groundwater recharge, and consequently disturb the hydrological cycle in a watershed. Increase of IC in a watershed can cause more frequent flooding, higher flood peaks, groundwater drawdown, dry river, and decline of water quality and ecosystem health. There has been an increased public interest in the institutional adoption of LID(Low Impact Development) and GI(Green Infrastructure) techniques to address the adverse impact of IC. The objectives of this study were to construct the modeling site for a samll urban watershed with the Storm Water Management Model(SWMM), and to evaluate the effect of various LID techniques on the control of rainfall runoff processes and non-point pollutant load. The model was calibrated and validated using the field data collected during two flood events on July 17 and August 11, 2009, respectively, and applied to a complex area, where is consist of apartments, school, roads, park, etc. The LID techniques applied to the impervious area were decentralized rainwater management measures such as pervious cover and green roof. The results showed that the increase of perviousness land cover through LID applications decreases the runoff volume and pollutants loading during flood events. In particular, applications of pervious pavement for parking lots and sidewalk, green roof, and their combinations reduced the total volume of runoff by 15~61 % and non-point pollutant loads by TSS 22~72 %, BOD 23~71 %, COD 22~71 %, TN 15~79 %, TP 9~64 % in the study site.

• Archives of design research
• /
• v.19 no.2 s.64
• /
• pp.99-108
• /
• 2006

Based on the results from the already published 'A study on factors that make busy of street space' and 'A study on street the image evaluation of streetscape', this study is an attempt to explore factors, other than the structural factors, that compose the street space and affect the image of street to be more lively. First of all, this study was mainly concentrated on the structure of street space that fits the theory of the previous two theses, stating that the structural ratio ($D/H=0.5{\sim}2$) gives the street an interesting image. The next study subject was the street space that exhibits the amenity and busy of image according to the space structure ratio. I defined that exhibiting amenity and busy means the activation of the street space, and I attempted to extract the activation factors from the component elements. The street space that shows amenity and busy image after the activation was named as 'lively street space' in this study. Furthermore, I selected 20 street spaces, after classifying the whole, according to nations and local characteristics as the previous theses had done and looked for the 'lively street space', whose structural ratio was not in the range of $D/H=0.5{\sim}2$ and the factors that contributed to the Image. As the result, I founded that in case of the business areas with the ratio of $D/H=0.5{\sim}2$, street activation factors were hydroponic facilities, sidewalks, and wayside buildings and In case of the commercial areas, the factors were sidewalk, wayside buildings, hydroponic facilities, and illumination facilities. Especially, 5 commercial areas in Korea and 1 business areas in Japan did not have the structural ratio of $D/H=0.5{\sim}2$, but still exhibited lively image as streets. This was because aside from the structural element, other street activation factors such as facilities also had major contribution in these streets. In other words, in commercial areas in Korea have wayside buildings, sidewalks, and hydroponic facilities as activating factors, whereas in street spaces in business areas in Japan, hydroponic facilities, wayside buildings, and sidewalk factors are influential to the activation of street spaces.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.12 no.6
• /
• pp.97-107
• /
• 2013

On the Staggered Crosswalks, pedestrians cross the crosswalks two times. This method can reduce the cycle, the vehicle delay and the walking distance by increasing the major direction of green time. The safety of pedestrians is also effective. This study suggests the warrant of the facilities of island width and length etc. by considering the road structure and pedestrians. Also this study suggests the standard of the safety through the accident analysis of Staggered crosswalks and General Crosswalks. In the results, accident rate of the Staggered Crosswalks 18.3(100 million vehicle-km) was lower than the accident rate of the General Crosswalks 28.3(100million vehicle-km). By understanding the start point of crossing of the Staggered Crosswalks, the analysis of the location and types of accident suggests the safety zone(spare space). The setting warrants of Staggered Crosswalks are 4 lane over the road and the 2 meter over sidewalk width of island. The minimum length of the Pedestrian island was doubled compared to the crosswalks width. And the maximum length was set by considering the wait time of the pedestrians.

• Archives of design research
• /
• v.17 no.2
• /
• pp.135-146
• /
• 2004

The street landscape image is through complex experience of psychological factor by the visionary experience and physical factor by recognize a street's structure. Therefore, the need for analyz-ing and evaluating the psychological and physical aspect of street view was aroused, and how much it has an effect on the outcome. Above all, a definite street standard of a region in its characteristics was selected to analyze the street characteristics of a region (commercial, business, and complex area). A questionnaire was used to measure psychological information felt in a street area. As a result, the street image holds similar characteristics according to regional characteristics and the amenity and busy condition play a major role in having the effect. To know of the effect of street of a region that is known to cause the busy in a region, the discriminant analysis was made between the selected regions to analyze the difference. As a result, the difference of the width of street, ratio of widths of sidewalk and driveway, the ratio of height of a building and width of street, and the difference of tree-planting ratio were main factors which helped to feel more of the contrary of street in a region. Current research has helped to make more precise analysis and evaluation of all kinds of street images, and suggested different means of having more live image in a street region through physical factors. To create more the busy in a region, it is considered that analyzing the image of a street would be used more.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.891-894
• /
• 2008

This study was performed to investigate how to design, where to construct, why to degrade, what plan to use systematically the underground structures such as underpass, underground passageways. About 50% of the underground structures are located on Seoul, Kyungi-Do. In design of the underground structures such as underpass, underground passageways, the required conditions are defined. And also in construction stage, the conditions of soil, required structure depth, site characteristics, reasonable construction method, are investigated. In the selection of details for underground structure, the items mainly considered, are the wall and column type, the sidewalk type, anchoring-system type, the water-proofing method, entranc shape. The reason and the adequate measures for the degradation of concrete structure are also investigated. The initial cracking properties due to the thermal characteristic are considered. The state of the art report on the new technologies are reviewed. The recent project for the systematically application to the underground structures is reviewed.

• Korean Journal of Construction Engineering and Management
• /
• v.13 no.2
• /
• pp.58-69
• /
• 2012

In modern society, rooftops and underground spaces are utilized for overcoming a confined space limitation of metropolitan areas. Therefore, floor covering construction is also increasing steadily. From the user's viewpoint, skid resistance performance of floor covering methods is a very important performance criterion for safety and amenity, but an appropriate design and assessment criteria for skid resistance performance are not available. This study presents the skid resistance performance assessment method of floor covering methods considering the sidewalk skid resistance standard of Seoul city and the guideline of the Ministry of Land, Transport and Maritime Affairs(MLTM) of Korea for road safety facilities'installation and maintenance. For this research, three alternatives among urethane floor covering methods are selected and their skid resistance performance is analyzed through an experimental study. The analyzed performance is also evaluated by the skid resistance performance assessment method. Finally, the comprehensive performance assessment including the results of skid resistance performance assessment is conducted by Value Analysis(VA) in order to encourage the construction methods of floor covering which have a high skid resistance performance. As a result of VA, the particle method which the skid resistance performance is improved up to four times more than other alternatives shows the highest performance index of 83.86.

• Korean Journal of Construction Engineering and Management
• /
• v.11 no.6
• /
• pp.111-121
• /
• 2010

As the customer's interest for sidewalk block in the street or apartment complex is increasing, the materials of block which had been a concrete block exclusively are varied to clay paver, native rock and wood etc. Especially, the sales volume of clay paver which is environment-friendly and ergonomic is dramatically increasing every year with two digits growth rate, however, many problems like "Edge Cracking" "Freezing Breakage" "Bending Breakage" "Joint Gap" are happening frequently within a couple of hours after installation due to the durabilities. Because of the characteristics of Ceramic products, clay pavers are very easy to be broken when they are bumped against each other. In addition, they are relatively fragile by a freezing expansion breakage when exposed to water due to hydrophilic property as well as the intensity and absorptance of the products are varied with small difference from the production process such as production equipment and process control. Therefore, it costs a lot of money to repair the breakdown unless production and installation is carried out according to the strict criteria of the quality control. In this study, the symptoms of breakdown frequently happened in clay paver are classified by each type and finally the solution for this problem in the production of brick, installation and criteria of quality control through compressive strength and absorptance test is suggested.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.1D
• /
• pp.91-98
• /
• 2011

Recently, the usage of elastic paving using EPDM Chip instead of pedestrian sidewalk blocks or permeable concrete used mostly for pedestrian walk, trails and in parks has been increassed as it can absorb impact during walking and produce wide range of colors and designs. However, the properties of EPDM Chip including elasticity and durability are decreased when exposed to ultraviolet ray and scenic paving functions through various colors are lowered due to the yellowing phenomenon. In this study, ultraviolet ray accelerated weathering test has been conducted to analyze the color changes in EPDM Chip and polyurethane resin, which are the main ingredients of elastic paving, when exposed to ultraviolet ray. The color differences are quantitatively analyzed through the color value coordination of the colored space by using the color difference scheme. The experimental results show that the color changes in BL polyurethane resin which is used most frequently at present was larger than that of EPDM Chip. Moreover, the total color difference, ${\Delta}E$, of BC polyurethane resin are 3.162 on the $14^{th}$ day of commencement of acceleration, which is 6 times greater color change resistance against ultraviolet ray than that of BL polyurethane resin with total color difference of 20.639. Therefore, the usage of BC polyurethane resin, which is manufactured to have chain-type molecular structure by using the isocyanate as the HMDI at the time of producing polymer, as binder in elastic paving with EPDM Chip is found to be a highly efficient method of restraining the color changes due to the ultraviolet ray.