PURPOSES : The purpose of this study is to establish a scientific and rational structure pavement maintenance technique and management standard through field investigation and analysis method development for measuring damage to structure pavement such that fundamental quality improvement can be promoted and the life of pavement prolonged. METHODS : In this study, the crack, plastic deformation, IRI, and SPI values measured using the existing RoadScanner of a corresponding section, as well as the relative dielectric constant values of a lower deck measured using a ground penetrating radar are reduced. The results of a small impact load test are verified by comparing the modulus of elasticity measured. RESULTS : In the Hongjecheon Overpass, when comparing the suspicion points of deterioration between the center of the lane and the 25 measurement data points of the wheel pass section based on the elastic modulus of the light falling weight deflectometer (LFWD), it is discovered that the lane comprises four centers (16%) and 18 wheelpaths (72%). The percentage of suspected deterioration points in the center is higher than that in the wheelpath. In addition, in the case of the Seoho Bridge, by comparing the suspicious points of deterioration for 11 measurement data points in the middle of the lane and the wheelpath section based on the elastic modulus of the LFWD, it is discovered that five points (45%) in both the middle of the lane and the wheel pass are similar. CONCLUSIONS : In this study, a comparative analysis of the LFWD elastic modulus and SPI factors (crack rate, plastic deformation, and IRI) of the Hongjecheon Overpass and Seoho Bridge is conducted to confirm the factors of pavement breakage. Among them, it is confirmed that it affects the pavement condition the most; however, to consider the LFWD elastic modulus as an evaluation criterion for future structure pavement, the data points must be verified via additional experiments to ensure high reliability.
본 연구는 도로시설물의 염화칼슘 제거를 위한 미세기포 세척장비의 최적 운용조건에 대하여 성능평가를 수행하였다. 실험에 사용된 미세기포의 직경은 196.6±100.6nm 에 1.36×108개/ml의 농도를 나타낸다. 세척장비의 분사장치에 대한 실험 성능결과, 100bar의 분사압력에서 100cm, 150cm 분사거리에 약 93%, 91%의 세척효율이 나타나는 것으로 확인되었다. 미세기포 생성(순환)횟수를 2-6회로 증가시킴에 따라 최소 1%에서 7%까지 염화물 제거율이 높아짐을 확인하였다. 미세기포 생성 공기유량을 4 ml/min에서 0.5 ml/min으로 낮춤에 따라 세척효율이 최대 30%까지 증가하는 것이 확인되었다. 일반 상수도와 미세기포의 세척효율은 미세기포가 일반상수도 보다 세척효율이 25% 높게 나타났다.
In contemporary society, vibration and noise in the road nearby buildings have become social problems as vehicles operation has increased. Especially, in the case of the building used to art performance, available suitability of the building is tested by the indoor noise class. Therefore, the purpose of this paper is the measurement of the structure-borne noise of Seoul Art Center nearby Umyeonsan tunnel and analyzing the effects of countermeasure to it. To measure the effects of countermeasure, not only structure-borne noise is measured, but also the vibration is measured, before and after the construction of pavement using pad and porous asphalt. Consequently, the sound pressure level in art center 1st floor is reduced after mat pavement method, structure-borne noise that was high in 25Hz wide-band before pavement decreased regardless of experimental vehicle's velocity. Using porous asphalt pavement the noise was reduced about 3 dB(A).
PURPOSES: In areas of high traffic volume, such as expressway across large cities, the amount of nitrogen oxides (NOx) emitted into the atmosphere as air pollution can be significant since NOx gases are the major cause of smog and acid rain. Recently, the importance of NOx removal has arisen in the world. Titanium dioxide (TiO2), that is one of photocatalytic reaction material, is very efficient for removing NOx. The NOx removing mechanism of TiO2 is the reaction of solar photocatalysis. Therefore, TiO2 in road structure concrete need to be contacted with ultraviolet rays (UV) to be activated. In general, TiO2 concretes are produced by replacement of TiO2 as a part of concrete binder. However, considerable portion of TiO2 in concrete cannot contact with the pollutant in the air and UV. Therefore, TiO2 penetration method using the surface penetration agents is attempted as an alternative in order to locate TiO2 to the surface of concrete structure. METHODS: This study aimed to evaluate the NOx removal efficiency of photocatalytic concrete due to various TiO2 application method such as mix with TiO2, surface spray(TiO2 penetration method) on hardened concrete and fresh concrete using surface penetration agents. The NOx removal efficiency of TiO2 concrete was confirmed by NOx Analyzing System based on the specification of ISO 22197-1. RESULTS: The NOx removal efficiency of mix with TiO2 increased from 11 to 25% with increasing of replacement ratio from 3 to 7%. In case of surface spray on hardened concrete, the NOx removal efficiency was about 50% due to application amount of TiO2 with surface penetration agents as 300, 500 and 700g/m2. The NOx removal efficiency of surface spray on fresh concrete due to all experimental conditions, on the other hand, which was very low within 10%. CONCLUSIONS: It was known that the TiO2 penetration method as surface spray on hardened concrete was a good alternative in order to remove the NOx gases for concrete road structures.
PURPOSES : About 35% of air pollutant is occurred from road transport. NOx is the primary pollutant. Recently, the importance of NOx removal has arisen in the world. TiO2 is very efficient for removing NOx by photocatalytic reaction. The mechanism of removing NOx is the reaction of photocatalysis and solar energy. Therefore, TiO2 in concrete need to be contacted with solar radiation to be activated. In general, TiO2 concrete are produced by substitute TiO2 as a part of concrete binder. However, 90% of TiO2 in the photocatalysis can not contacted with the pollutant in the air and solar radiation. Coating and penetration method are attempted as the alternative of mixing method in order to locate TiO2 to the surface of structure.
METHODS : The goal of this study was to attempt to locate TiO2 to the surface of concrete, so we can use the concrete in pavement construction. The distribution of TiO2 along the depth were confirmed by basing on the comparison of TiO2 compare by using the EDAX(Energy Dispersive X-ray Spectroscopy).
RESULTS : TiO2 were distributed within 3mm from concrete surface. This distribution of TiO2 is desirable, since the TiO2 induce photocatalysis are located to where they can be contacted with the air pollutant and solar radiation.
CONCLUSIONS : Nano size TiO2 is easily penetration in the top 3mm of concrete surface. By the penetration TiO2 concrete can be produced with the use of only 10% of TiO2, by comparing the mixing types.
PURPOSES : This study is to investigate the relationship of socioeconomic characteristics and road network structure with traffic growth patterns. The findings is to be used to tweak traffic forecast provided by traditional four step process using relevant socioeconomic and road network data. METHODS: Comprehensive statistical analysis is used to identify key explanatory variables using historical observations on traffic forecast, actual traffic counts and surrounding environments. Based on statistical results, a multiple regression model is developed to predict the effects of socioeconomic and road network attributes on traffic growth patterns. The validation of the proposed model is also performed using a different set of historical data. RESULTS : The statistical analysis results indicate that several socioeconomic characteristics and road network structure cleary affect the tendency of over- and under-estimation of road traffics. Among them, land use is a key factor which is revealed by a factor that traffic forecast for urban road tends to be under-estimated while rural road traffic prediction is generally over-estimated. The model application suggests that tweaking the traffic forecast using the proposed model can reduce the discrepancies between the predicted and actual traffic counts from 30.4% to 21.9%. CONCLUSIONS : Prediction of road traffic growth patterns based on surrounding socioeconomic and road network attributes can help develop the optimal strategy of road construction plan by enhancing reliability of traffic forecast as well as tendency of traffic growth.
본 연구는 광릉 지역의 활엽수 천연림과 도로 주변에서 서식지 구조와 조류군집의 특성을 파악하기 위해 2005년 10월부터 2006년 8월 사이의 기간 동안 수행되었다. 활엽수 천연림과 도로 지역의 서식지 환경은 매우 큰 차이가 있는 것으로 나타났다. 활엽수 천연림은 대경목의 비율이 높고 상층 임관이 잘 발달해 있는 반면, 도로에서는 소경목이 대부분을 차지하였으며, 상층임관의 발달이 적은 반면 하층식생의 피도가 높았다. 계절별 조사 결과 활엽수 천연림에서는 모두 37종의 조류가 관찰되었으며, 도로에서는 20종이 기록되었다. 4계절에 있어서도 활엽수 천연림 이 도로보다 관찰 종수, 개체수 및 종다양도에 있어서 모두 높은 것으로 나타났다. 또한 길드 구조에 있어서도 활엽수 천연림 지역에서는 수관층 및 수동(나무구멍)에서 먹이와 둥지를 얻는 조류들이 많이 관찰되었으며, 도로에서는 관목이나 지면을 이용하는 조류가 많이 기록되었다. 두 지 역은 인접해 있음에도 불구하고 조류 군집의 특성에 있어서 큰 차이를 보였다. 이러한 차이는 두 지 역 간 서식환경의 차이와 깊은 연관이 있는 것으로 판단된다.
최근 이상기후로 인한 돌풍과 태풍에 의해 도로표지 구조물은 지속적인 풍해를 입고 있다. 풍하중에 지배적인 영향을 받는 도로표지 구조물의 구조 안전성 확보를 위하여 내풍성 향상 도로표지 구조물에 대한 연구가 필요하다. 본 연구에서는 내풍성 향상 도로표지 구조물로 통풍형 도로표지 구조물을 제안하였다. 통풍형 도로표지 구조물은 기존 표지판에 일정한 간격과 직경의 천공을 갖는 도로표지 구조물이다. 천공의 직경과 간격에 대한 최적의 제원을 도출하기 위하여 통풍형 도로표지판의 항력계수 감소 효과 분석과 반사율 실험을 진행하였다. 통풍형 도로표지판을 적용한 표준 도로표지 구조물의 풍하중 저감 효과와 지주 단면 감소 효과를 분석하였다.