• Korean Journal of Health Education and Promotion
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• v.22 no.4
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• pp.203-213
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• 2005

Purpose: To assess the environmental hazards of falling accident in the homes of the elderly. Method: 222 homes of the elderly were assessed by the home environmental Checklist from May to July in 2003. Results: The mean score of home environmental hazards for fall were 13.19 with the highest score being 49, ranging from 4 to 24. The bathroom was the most hazardous place in the home, porch came next bedroom, kitchen, living room and stair followed them. The floor surface such as finishes and non-skid mats was the most hazardous interior factor in the home, using bathroom came next furniture and illumination followed them. The floor surface such as finishes and non-skid mats in the bathroom, kitchen, living room and porch, illumination of bedroom and stair were the most prevalent hazards in the home of interior. Of the 49 potential hazards, bathroom grab bar was the most prevalent one with 89.9%, and non-skid rugs in the porch, bathroom and kitchen, safety of dinner table, the threshold and furniture of porch, and illumination of bedroom were prevalent more than half of the home under assessing. Men, living in the separate house or villa with stairs were in more hazardous environments. Conclusion: To reduce the potential hazards of fall accident in the home, improving hazards relating to floor surface such as slip resistance surface and mats is important specially those of the separate house or villa with stairs.

• 한국도로학회:학술대회논문집
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• 2009.11a
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• pp.213-220
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• 2009

• International Journal of Highway Engineering
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• v.14 no.6
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• pp.45-55
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• 2012

PURPOSES : Skid resistance and noise of roads highly depend on the characteristics of pavement texture. Therefore, estimation of texture characteristics may give useful information for the skid resistance and noise of road. Generally, Sand Patch Test is performed in order to estimate MTD(Mean Texture Depth). However, it is time-consuming and needs traffic control. This study aimed to investigate the effectiveness of measurement texture depth using the Portable Laser Profiler that give the MPD(Mean Profile Depth). METHODS : MTD and MPD were collected on the number of expressway sections including Central Inland Test Road sections in Korea. Statistical analysis are performed to establish the relationship between MTD data based on Sand Patch Test and MPD data obtained by the Portable Laser Profiler. RESULTS : Linear relationship MPD and MTD is observed for both of asphalt pavement and concrete pavement such as R-square of 0.51 to 0.58. CONCLUSIONS : Even though, the test method and definition of MPD and MTD are different. EMTD(Estimated Mean Texture Depth) can be obtained by using the correlationship between MPD with MTD.

• Journal of the Korean Ceramic Society
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• v.31 no.7
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• pp.767-771
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• 1994

In a salb-preheating furnace of steel-making industry, the oxidation/degradation behavior of Cr3C2 ceramic composited dkid button reaction with scale in Fe-oxide system occurs and was thermodynamically examined. The reaction of scale with Cr3C2 skid button produces Cr3C2(s) and C(s), and Co gas is then evolved from the reaction of C(s) with Fe-scale. Cr3C2(s) from oxidation of Cr3C2(s) reacted with Fe-oxide(s) becomes high-melting chromite. The chromite acts as protection layer against further oxidation and improves resistance of the reaction of Cr3C2 skid button with Fe-scale.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.117-127
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• 2007

The exposed aggregate PCC(EAP) pavements have been successfully used in Europe and Japan as low-noise pavements. Coarse aggregate are exposed on the pavement surface texture of EAP by removing mortar of surface. The pavement surface texture should maintain not only low-noise characteristic but also adequate skid resistance level during the performance period. Skid resistance decreased with wearing and polishing of tire and pavement surface due to the repetition of tire-pavement contact. Since the tires mainly contact the exposed coarse aggregate, the shape and rock type of coarse aggregate significantly influence wearing and polishing of EAP pavements. The test for resistance to abrasion coarse aggregate by use of the Los Angeles machine(KS F 2508) and the method of test for resistance to abrasion coarse aggregate by use of the Accelerated Polishing Machine(ASTM D 3319-90) are generally used to evaluate polishing characteristics of aggregate. In this study, polishing of coarse aggregate of different five rock types were evaluated by KS F 2508(LA abrasion test) and ASTM D 3319-90(PSV method). The results of LA abrasion test and PSV method were contrary to each other. Since LA abrasion test is estimated the quantity of abrasion by the impact of aggregate, it may not be adequate to evaluate the polishing of aggregate by the repetition of tire. In the case of PSV method, the resistance of polishing is estimated the skid resistance variation of polished aggregate after repetition of tire. The PSV method is adequate for the evaluation on polishing of coarse aggregate. From the test results of PSV method, it was founded that rock type, specific gravity, coarse aggregate angularity, flat or elongated particles in coarse aggregate are significant to the resistance characteristic of coarse aggregate.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.69-76
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• 2020

Global warming is a very important problem as it causes rapid climate change and natural disasters. Therefore, researches related to renewable energy are being actively conducted while promoting policies such as reducing carbon dioxide emission and increasing the proportion of renewable energy. Solar power generation is being applied in urban areas like BIPV as well as existing idle areas outside the city. Therefore, in this study, precast concrete blocks developed for paving roadways capable of solar power generation were designed and constructed. For the evaluation of field applicability for 6 months, skid resistance and block settlement were measured. As a result of the experiment, it was found that skid resistance satisfies the standard of general roadway in Korea, but not the standard of highway. The skid resistance tended to decrease as time passed. In addition, the settlement of the block gradually increased slightly, but it is much smaller than the allowable settlement of the roadway. Therefore, it is necessary to establish a maintenance period and method based on the periodic measurement results in the future.

• Rubber Technology
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• v.5 no.2
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• pp.94-103
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• 2004

The present work describes modification of dual phase filler by electron beam irradiation in presence of multifunctional acrylates like trimethylol propane triacrylate (TMPTA) or silane coupling agent like bis (3-triethoxysilylpropyltetrasulphide) and in-fluence of the modified fillers on the physical properties of styrene-butadiene rubber (SBR) vulcanizates. Modulus at 300 % elongation increases whereas the tensile strength decreases with increase in radiation dose for the dual phase filler loaded styrene-butadiene rubber vulcanizates (SBR). However, modulus and tensile strength significantly increase, which is more, pronounced at higher filler loadings for TMPTA modified dual phase filler loaded SBR. These changes in properties are explained by the equilibrium swelling data and Kraus plot interpreting the polymer-filler interaction. Electron beam modification of the filler results in a reduction of tan ${\delta}$ at $70^{\circ}C$, a parameter for rolling resistance and increase in tan ${\delta}$ at $0^{\circ}C$, a parameter for wet skid resistance of the SBR vulcanizates. Finally, the influence of modified fillers on the properties like abrasion resistance, tear strength and fatigue failure and the improvement in the properties have been explained in terms of polymer-filler interaction.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.115-123
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• 2011

This study was conducted to investigate the early-age behavior and performance of precast pavements constructed by replacing existing asphalt pavements for an intersection in urban bus only lanes. The monitoring items included level differences between asphalt pavement and precast panels at the beginning and ending locations of the precast pavement, level differences and joint widths between precast panels, precast panel settlement, and skid resistance of the panel surface. At a certain time after the construction, the diamond grinding method was applied and its effect was also investigated. The monitoring results showed that as time went by, the panel level, joint width, settlement, and skid resistance were not much varied. That implied the stable sustaining of external loads by the precast pavements. In addition, it was verified that employing diamond grinding could reduce the level differences between precast panels.

• International Journal of Highway Engineering
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• v.12 no.1
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• pp.29-37
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• 2010

Porous pavements can provide road users with beneficial characteristics such as skid resistance and surface water drainage under rainy condition, and they cause less tire-road noise than conventional hot mix asphalt(HMA) pavements. However, voids of porous pavements are easily clogged by road debris at early stages, which leads to frequent maintenance works. Therefore, this study focused on the way of minimizing void clogging in porous pavements. During mixture design, the quantity of coarse aggregate has been increased to form many straight void conduits (SVCs) in porous HMAs. These SVCs were found to be effective resisting the void clogging problems. Four different porous HMAs(19mm, 13mm, 10mm, and 8mm) were developed and placed on highway roads. Their performances were validated with field tests during the past four years.

• International Journal of Highway Engineering
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• v.12 no.3
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• pp.1-8
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• 2010

This study is performed to evaluate the physical and mechanical characteristics of an acryl polymer concrete that is developed as an overlay material for cement concrete slabs and pavements. Various laboratory tests including viscosity, flow, compressive strength, flexural strength, tensile strength, linear shrinkage, thermal expansion and thermal compatibility tests are performed. It is observed from the laboratory tests that the acryl polymer concrete developed in this study satisfies all the requirements suggested by ACI guideline. In addition to the laboratory tests, an accelerated performance testing (APT) is conducted to validate the performance of the acryl polymer concrete. During the APT, no significant distresses are observed until 15,903,939 cycles of equivalent single axle loading is applied. Finally, a 10mm thick overlay with the acryl polymer concrete is applied on top of an old deteriorated concrete pavement to evaluate field performance. Right after the field construction, skid resistance, noise and roughness are measured. The skid resistance and noise level have been significantly improved while the roughness is increased. Periodic investigation for the field study section will be conducted to evaluate the long-term performance.