PURPOSES : This study evaluates the noise reduction effects of various road paving methods and focuses on low-noise pavements as a cost-effective alternative to sound barriers and tunnels. In addition, this study assesses how noise levels vary with vehicle speed across different paving methods. METHODS : An analysis of variance (ANOVA) was conducted to evaluate the noise performance of different paving methods, and this followed by a post-hoc analysis to examine the differences among the paving methods. Another ANOVA was conducted to evaluate the impact of speed on noise performance. This ANOVA was followed by a post hoc analysis to assess differences by speed. Finally, a covariance analysis was conducted, using speed as a covariate, to evaluate the noise reduction effects of the various paving methods. RESULTS : The results of the analyses showed that noise levels follow the order of General ≈ Non-draining > Single-layer ≈ Doublelayer, thus grouping the paving methods into two categories with significant differences in noise performance. In addition, the noise levels increased with speed, except at 70 and 80 km/h. The covariance analysis resulted in a regression coefficient of 0.267 for speed across all paving methods. A post-hoc analysis grouped the paving methods into three distinct categories: General, Non-draining ≈ Single-layer ≈ Double-layer, with notable noise differences between them. CONCLUSIONS : The analysis of noise performance showed that both the paving method and speed significantly affected the noise levels. The covariance analysis, using speed as a covariate, revealed a consistent regression coefficient of 0.267 across all the paving methods. After controlling for speed, noise differences were observed. The General method showed higher noise levels than did the Non-draining, Doublelayer, and Single-layer methods.

본 논문에서는 다양한 기상 조건에서 시인성과 내구성을 향상시키도록 설계된 도로 표시용 UV 경화 코팅 시스템 개발을 위해 수행한 연구의 결과를 나타내었다. 제조된 UV 코팅을 사용해 차선 표시의 재귀반사도와 내마모성을 강화하고 포장가속시험(APT), 휠 트래킹 내구성 테스트 등 다양한 테스트를 통해 성능을 평가하였다. 이 결과를 바탕으로 도로 안전을 위한 야간 시인성 및 미끄럼을 개선하 고자 한다.

도로에서 발생하는 대기오염의 주요 원인은 자동차 등의 연료연소로 인해 발생하는 미세먼지(PM), 질소산화물(NOX), 황산화물(SOX), 암모니아(NH3), 오존(O3) 등이며, 특히 미세먼지와 질소산화물은 도로를 이용하는 운전자와 보행자의 건강에 부정적인 영향을 미치는 것으로 알려져 있다. 본 연구에서는 버스정류장에 설치되는 미세먼지 저감시설의 미세먼지 저감효과를 분석하기 위하여 미세먼지 저 감능력을 실증할 수 있는 실대형 미세먼지 실증인프라와 실규모의 버스정류장을 이용하였다. 미세먼지 실증인프라에서 미세먼지 저감 시설이 설치되는 실험군(2곳)과 미설치되는 대조군(1곳)을 대상으로 미세먼지(PM10) 발생농도를 측정하였으며, 미세먼지 저감시설의 미 세먼지 저감효과를 분석하기 위하여 미세먼지(PM10)의 발생확률과 확률밀도함수를 산정할 수 있는 통계학적 방법인 Anderson-Darling 테스트(AD 테스트)를 이용하여 분석하였다. 미세먼지 저감시설의 미세먼지 저감효과는 대기질지수(AQI)의 기준을 준용하여 실험군ㆍ 대조군의 미세먼지 농도발생확률을 비교하여 정량적ㆍ정성적으로 분석하였다. 미세먼지(PM10) 농도발생확률 산정결과, AQI ‘보통’의 경우, 실험군 측정지점 1, 2와 대조군의 농도발생확률은 각각 77.24%, 63.26%, 0.00%로 대조군에 비해 실험군의 측정지점 1, 2에서 높 게 나타났으며, AQI ‘나쁨’의 경우, 실험군 측정지점 1, 2와 대조군의 농도발생확률은 각각 21.70%, 35.09%, 100.00%로 나타나 실험군 내의 미세먼지(PM10) 발생농도가 대조군과 비교해 개선되는 것으로 분석되었으며, 대조군 내부의 미세먼지 농도의 변화는 거의 없는 것으로 나타났다. 일반적으로 미세먼지를 측정하는 방식인 중량법과 베타선법을 통한 미세먼지 저감효과 분석방법은 시간당 평균으로 측정한 미세먼지 농도만 비교 가능하므로 정성적인 효과분석이 미비해 본 연구를 통해 소개한 통계학적 방법이 정량적 분석 뿐만 아 니라 정성적 분석에도 효과적일 것으로 기대하고 있다.

콘크리트 도로포장의 손상은 차량의 이동에 의한 진동, 겨울철 제설제 사용, 동결융해 작용 등이 주요 손상원인으로 나타나고 있다. 이러한 손상을 해결하기 위하여 열화 원인에 능동적으로 대응하는 보수재료 및 방법이 적용되어야 하나, 일반적으로 단면복구, 부분보 수를 반복적으로 사용함으로써, 지속적인 열화 현상의 발생으로 도로포장의 기능을 상실하게 된다. 또한, 기존에 사용되고 있는 보수 재료 중 무기계 보수재료는 폴리머 모르타르, 에폭시수지 모르타르 등이 있다. 이러한 재료는 높은 압축강도를 가지고 있으나, 취성 및 부착력이 약한 단점을 나타내고 있다. 따라서 본 연구에서는 보통포틀랜드시멘트(Ordinary Portland Cement), 칼슘알루미네이트계 재 료인 칼슘설포알루미네이트(Calcium Sulfo Aluminate) 및 비정질 알루미네이트(Amorphous Calcium Aluminate)를 사용한 보수 모르타르의 압축강도 및 내동해성을 평가하였다. 보수 모르타르의 압축강도를 분석한 결과, 비정질 알루미네이트를 사용한 보수모르타르의 압축강 도가 보통포틀랜드시멘트 및 칼슘설포알루미네이트를 사용한 보수 모르타르보다 우수하게 나타나는 것을 확인하였다. 한편, 보수 모르 타르의 내동해성 평가는 ASTM C 666 A법에 준하여 실험을 진행하였다. 그 결과, 칼슘설포알루미네이트 및 비정질 알루미네이트를 적용한 보수 모르타르의 상대동탄성계수가 300사이클에서 약 90%이상으로 나타나 보통포틀랜드시멘트를 사용한 보수 모르타르보다 우수한 내동해성을 나타내었다. 따라서, 칼슘설포알루미네이트 및 비정질 알루미네이트를 적용한 보수 모르타르는 우수한 압축강도 및 내동해성을 나타냄으로써 도로포장의 보수재료로 사용이 가능할 것으로 판단된다.

최근 결빙으로 인한 교통사고가 빈번히 발생하고 있으며, 도로순찰시 육안 인식이 어려운 도로살얼음 검지를 위해 다양한 방식의 검지센서가 도입되고 있다. 본 연구에서는 국내외 상용화되어 있는 차량부착식 노면상태 검지센서에 대한 현장 검증을 통해 국내 도 로조건에의 적용 가능성을 검토하였다. 차량부착식 검지센서의 성능을 평가하기 위해 한국건설기술연구원의 연천SOC실증연구센터 내 의 도로기상재현 실험시설에 결빙(Ice), 습윤(Wet), 건조(Dry) 등 3가지의 노면상태가 육안으로 명확히 구분이 가능하도록 도로환경을 구현하였으며, 센서종류별로 차량에 부착하여 다양한 도로상태를 측정하였다. 평가결과 노면상태 측정결과의 정확도는 높은 것으로 나 타났으나, 그 외의 측정항목의 정확도는 상당한 차이가 발생하기도 하였다. 향후 다양한 도로환경 조건에서 추가적인 시험을 통해 차 량부착식 노면상태 검지센서의 현장적용을 기반자료로 활용할 수 있을 것으로 판단된다.

PURPOSES : The purpose of this study is to provide basic data to improve the service life of asphalt pavement using basalt aggregate in Jeju Island by evaluating the performance of asphalt pavement through analysis of material and structural aspects. METHODS : To evaluate the performance of Jeju Island's asphalt pavement, cracks, permanent deformation, and longitudinal roughness were analyzed for the Aejo-ro road, which has high traffic and frequent premature damage. Cores were collected from Aejo-ro sections in good condition and damaged condition, and the physical properties of each layer were compared and analyzed. In addition, plate cores were collected from two sections with severe damage and the cause of pavement damage was analyzed in detail. RESULTS : About 45% of the collected cores suffered damage such as layer separation and damage to the lower layer. The asphalt content of surface layer in the damaged section was found to be 1.1% lower on average than that in the good condition section, and the mix gradations generally satisfied the standards. The density difference between the cores of each layer was found to be quite large, and the air voids was found to be at a high level. CONCLUSIONS : Test results on the cores showed that, considering the high absorption ratio of basalt aggregate, the asphalt content was generally low, and the high air voids of the pavement was believed to have had a significant impact on damage. High air voids in asphalt pavement can be caused by poor mixture itself, poor construction management, or a combination of the two factors. Additionally, the separation of each layer is believed to be the cause of premature failure of asphalt pavement.

PURPOSES : The purpose of this study was to quantitatively evaluate the variability of LiDAR performance indicators, such as intensity and Number of Point Cloud(NPC), according to various environmental factors and material characteristics. METHODS : To consider the material characteristics of road safety facilities, various materials (Reference Material(RM), reflective sheet, matte sheet, granite, plastic, and rubber) were used in a darkroom, and the performance indicators of LiDAR were repeatedly measured in terms of changes in the measurement distance, rainfall, and angle of observation. RESULTS : In the case of standard reflective materials, the intensity measurement value decreased as the measurement distance and rainfall increased. The NPC showed a tendency to decrease as the measurement distance increased, regardless of rainfall intensity. For materials with high-intensity values, it was found that rainfall intensity and color had negligible effect on the change in intensity compared with the measurement distance. However, for materials with low-intensity values, it was found that the measurement distance, rainfall intensity, and color all had a significant effect on the change in intensity. CONCLUSIONS : For materials with high-intensity values, it was found that rainfall and color had negligible effect on change in intensity compared with the measurement distance. However, for materials with low-intensity values, the measurement distance, rainfall, and color all had a significant effect on the change in intensity value.

PURPOSES : Experimental findings pertaining to the mechanical properties of calcium aluminate cement (CAC)-based repair mortars incorporated with anhydrite gypsum (AG) are described herein. METHODS : To prepare the mortars, three different levels of AG were adopted and the ratio of water–cementitious materials was fixed at 0.50. For comparison, mortar composed of ordinary Portland cement was prepared. The fluidity, setting time, compressive and bond strengths, absorption and surface electric resistivity of the mortars were measured at predetermined periods. RESULTS : The incorporation of AG increases the fluidity but decreases the setting time of the CAC-based repair material system. However, the AG in the CAC mixes does not effectively enhance the compressive strength of the mortars owing to the decreased formation of CA hydrates, such as CAH10 and C2AH8. Meanwhile, the mortar with 10% AG shows excellence absorption. CONCLUSIONS : The mechanical properties of CAC based-mortars rely significantly on the amount of AG incorporated. However, further studies regarding the microstructure and durability of CAC-AG repair mortars must be conducted to obtain the optimal mixture.

PURPOSES : In this study, a method for improving roadside barrier performance by introducing additional reinforcing materials without dismantling or drilling the old underperforming roadside barrier is developed based on the Installation and Management Guide for Roadside Safety Feature. METHODS : Reinforcing roadside barriers comprising reinforcement rails, impact absorbers, blockouts, and support reinforcement plates attached to an old underperformance roadside barrier were designed and manufactured. The manufactured prototypes were subjected to a vehicle crash test to verify their performance. RESULTS : In a structure whose performance is measurable after it collides with a large truck, the minimum strength of the structure to withstand the collision is maintained. Additionally, the safety of passengers measured via the collision test of a small vehicle is excellent. Hence, the reinforcement plan for the old underperforming roadside barrier satisfies all the performance evaluation standards. CONCLUSIONS : The cost of the improvement technology specifications proposed herein is approximately 50% lower than that of a SB3 level roadside barrier. The proposed method for improving the old underperforming roadside barrier is expected to be widely applied as it can be applied conveniently to road sites.

PURPOSES : In this study, the results of an intensive field survey of a composite pavement applied to an expressway in Korea are analyzed. The results are intended to be used as basic data for evaluating the composite pavement and for preparing quality control measures through a review and analysis of the change in the state of the tensile bonding strength of the composite pavement. METHODS : To evaluate, repeated field coring and indoor tensile bonding strength evaluations are conducted for five years, and the commonality evaluation of pavement using pavement condition investigation equipment is conducted annually. RESULTS : The results of this study show that the degree of reflective crack generation varies depending on the type of concrete pavement and type of asphalt mixture applied to the intermediate layer, and that the CRCP composite pavement exhibits better initial commonality than the JCP composite pavement. In addition, it is confirmed that the composite cross-section pavement section with MASTIC applied as an intermediate layer shows excellent adhesion performance between the lower concrete layers from the beginning of construction in all sections, as well as satisfied the quality control standards for good pavement and tensile adhesion even after approximately five years of public use. CONCLUSIONS : Based on a follow-up survey of the composite pavement testing sections, it is confirmed that the section constructed with the MASTIC intermediate layer and CRCP satisfies the quality control standards for good pavement conditions and tensile adhesion even after approximately five years of public use.

PURPOSES : The evaluation of the road pavement thickness in an apartment complex through a methodology for estimating the number of construction vehicles is presented. We also show the usability of the new design criteria. METHODS : A field survey plan was established by conducting literature and preliminary surveys, and the structural performance of each section of the road pavement was compared through a structural analysis program. The load on construction vehicles is required for analyzing the ESAL factors of construction vehicles; it is calculated as a methodology for estimating construction vehicles because it is difficult to measure the traffic volume through visual inspection. Accordingly, the extent of damage predicted by road pavement sections in apartment complexes was analyzed to examine the possibility of applying the methodology for estimating the number of construction vehicles. RESULTS : If the road crack exceeds 20% as a result of the site survey of a previous study, structural damage to the road pavement occurs from construction vehicles. Compared to the actual traffic volume observation, an error of 5% took place; therefore, it is necessary to perform a design such that the damage caused by the load of the construction vehicle be 15% or less for proper road performance. Structural analysis through the KENPAVE program showed that the damage caused by the load of the construction vehicle exceeded 20% in all sections except section B (with a thickness of 46 cm). CONCLUSIONS : Owing to the limitations of the test construction section and environmental conditions, it is necessary to assess the effects of various variables by conducting an analysis. This is expected to be applied as a design basis considering more reliable construction vehicles.

PURPOSES: The objective of this study is to evaluate the shear and tensile strength properties of adhesive road studs in asphalt and concrete pavements. METHODS: The 300 mm×300 mm×50 mm rectangular specimens were fabricated using asphalt and concrete mixture for installation of road studs. Four 140-mm-radius circular areas were milled on each specimen with depth of 5 mm to install the adhesive road studs. About 100 g of thermal melting adhesive was applied on the milled area, and then the road stud was bonded onto the surface of the asphalt and concrete mixture. Direct shear testing was conducted at a speed of 5 mm/min on the interface between road stud and asphalt and concrete materials. Tensile strength testing was also conducted on the prepared specimens by applying load with increase of 50 kPa per second. These tests were performed not only in dry condition but also in wet condition to determine the effect of moisture on the shear and tensile strengths. RESULTS : According to the shear testing results, the average shear strength of asphalt samples in dry and wet conditions are 0.509 and 0.234 MPa, respectively. From this testing, the shear strength of wet sample was found to be decreased by 50% with respect to that of the dry sample. Similar trends can be observed on the concrete samples. The average tensile strength of asphalt samples was 0.187 MPa at 1.5 mm of displacement in dry condition. The concrete sample has a 0.222 MPa average tensile strength, which is slightly higher than that of the asphalt sample because of the rough surface characteristics of the concrete sample. CONCLUSIONS: It is determined from this study that the shear and tensile strengths of road stud bonded on the surface of asphalt mixture are slightly lower than those on concrete samples. Regardless of the pavement type, the wet conditioning of the sample can decrease the shear and tensile strength by 50% those of the dry sample. In the future, the quality improvement of adhesive and increase of specific surface area should be considered to improve the bonding property between road stud and pavement surface.

도로 교량 시설물은 그동안 인적, 물적 자원의 이동을 원활하게 하여 지역 균형 발전을 도모할 뿐만 아니라, 생산성 증대에 기여함으로써 국가 발전의 토대가 되어왔다. 최근 시간이 지남에 따라, 사회기반 시설물의 노후화가 진행되고 있으며, 지속적 유지·관리를 통해 사회적 자산인 시설물 유지에 대한 필요성이 더욱 증대되었다. 도로교량 시설물의 점검 및 평가체계는 시설물의 현재의 상태를 정확히 진단하고, 시설물을 이용에 있어서 필요한 성능들의 만족 여부를 면밀히 평가할 수 있도록 해야한다. 이로써, 교통 인프라 시설을 유지관리하는데 필요한 합리적인 의사결정이 가능하다. 본 연구에서는 중소 도로 교량의 성능평가 도입을 위한 기초 연구를 위하여, 국내외 도로 교량 시설물의 점검 및 평가체계 비 교·분석 연구를 수행하였다. 기존 국내 도로 교량 시설물의 정기점검 및 정밀안전진단에서의 점검 항목 및 평가방식, 국내 제1 종 및 제2종 시설물 종합성능평가에서의 평가항목 및 체계 분석과, 제3종 시설물 안전등급 평가 매뉴얼의 평가항목 및 체계에 대한 대응 분석을 수행하였다. 또한, 국외 교량 점검 및 평가 매뉴얼을 분석을 통해, 국내 도로 교량 시설물의 점검 및 평가체 계와의 비교·분석 검토 연구를 수행하였다.

PURPOSES: The objective of this study is to evaluate the durable performance of combined organic and inorganic hybrid mortar as repair material (HRM mortar) for concrete road facilities via comparison with that of cement repair materials (IRM mortar). METHODS : To produce HRM mortars, inorganic materials as binder and 2 mineral fillers were adopted. The ratio of main resin versus hardener was fixed at 1:2. For comparison, IRM mortars made with cement repair materials were also manufactured. Compressive, flexural, and bonding strengths were measured at predetermined periods. For durability assessment, the scaling resistance, freezing & thawing resistance, rapid chloride penetration resistance, and acid attack resistance of those mortars were experimentally monitored. RESULTS: The durability performances of HRM mortars, especially with respect to freezing & thawing, rapid chloride penetration and acid attack, were identified to be much better than those of IRM mortars. This result implies that HRM is a highly promising and versatile material because of its excellent durability. CONCLUSIONS: It is concluded that the application of the combined organic and inorganic hybrid mortars is possibly an option for the repair of concrete road facilities exposed to aggressive environments.