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.

도로 포장 기술이 발달함에 따라 내구성 확보 등의 구조성능 중심에서 이용자의 승차감 및 소음 저감 등의 기능성 중심으로 변화하 고 있다. 최근 도로 소음에 대한 민원이 증가하고 있고 도로 소음으로 인한 피해를 보상하라는 판결 사례도 증가하고 있다. 이러한 문 제를 해결하기 위해 차량 소음 저감 효과가 우수한 저소음 포장을 적용하고 있다. 본 연구에서는 저소음 배수성 포장과 저소음 비배 수성 포장의 내구성 및 공용성을 평가하였으며, 기대수명 예측을 위해 국내에 있는 배수성 8종, 비배수성 3종의 제품을 이용하여 실내 성능 평가를 수행하였다. 국토교통부의 "아스팔트 콘크리트 포장 시공 지침(2021)"의 배수성 포장 품질기준 및 비배수성 혼합물에 대 한 품질기준에 따라 시험을 진행하였다. 아스팔트 혼합물의 생산, 저장, 운반 및 포설 시 아스팔트의 흘러내리는 양이 적합한지를 평 가하기 위해 드레인다운 시험을 진행하였고, 배수성 혼합물의 골재 비산 저항성을 평가하기 위해 칸타브로 손실률 시험을 진행하였다. 또한 포장의 수분 저항성을 평가하기 위해 인장강도비(TSR) 시험과 소성변형 저항성을 평가하기 위해 동적안정도 시험을 진행하였다. 이후, 배수성 포장의 투수 성능을 평가하기 위한 실내투수계수 시험을 진행하였고, 저소음 포장의 소음 저감 성능을 평가하기 위해 임 피던스 관을 이용한 흡음률 시험을 진행하였다. 시험 결과 모든 종류의 혼합물이 품질기준을 통과하여 충분한 기초 성능을 가지고 있 는 것으로 나타났고, 흡음률 시험의 경우 배수성 혼합물이 평균 0.779, 비배수성 혼합물이 평균 0.638의 흡음계수를 나타내었다. 배수 성 혼합물과 비배수성 혼합물의 평균 공극률은 각각 19.3%, 3.2%로 배수성 혼합물이 비배수성 혼합물에 비해 많은 공극률을 가지고 있어 소음 저감 성능이 비배수성에 비해 우수한 것으로 판단하였다.

한국 고속도로 포장은 1970년 경부고속도로 건설을 시작으로 많은 발전을 이루었으며, 최근 도로이용자에게 쾌적한 도로를 제공할 수 있는 배수성 아스팔트 포장에 대한 관심이 높아지고 있다. 본 연구에서는 한국 고속도로 배수성 아스팔트 구간에 대한 시공목적별, 신설과 유지보수 등을 구분하여 배수성 아스팔트 포장 적용현황을 분석하였다. 또한, 적용된 배수성 아스팔트 포장의 교통량을 조사 분석하였으며, 효율적인 교통량 그룹 선정 방법을 제시하였다. 고속도로에 적용된 배수성 아스팔트 포장의 전주기 평가를 위해 평가항 목을 제시하였다. 내구성평가 항목으로는 포장상태평가지수와 표면조도를 선정하였다. 기능성 평가 항목으로는 내부 공극 막힘여부를 확인할 수 있는 현장투수, 미끄럼저항지수, 포장노면과 타이어에서 발생하는 도로소음원 평가를 위한 도로소음을 선정하였다. 그리고 조사 항목들에 대한 배수성 아스팔트 포장의 전주기 평가를 통해 각각 조사 항목에 대한 정량적 분석평가를 수행하여 도로소음도 예 측식을 제안하였다.

PURPOSES : The exposed aggregate concrete pavement (EACP) is adopted to achieve low traffic noise and long-term skid resistance in European countries such as Belgium and Germany. In Korea, it is first introduced at the Myeon Cheon field site in 2010. It reduces 3 dB(A) from tire–pavement noise compared with transverse tining. Recent investigations show that EACP can reduce tire–pavement noise by an additional 5 dB(A) compared with transverse tining. In this study, the tire–pavement interaction noise of EACP is compared with that of conventional pavements such as asphalt pavement, next-generation concrete surfaces (NGCS), and transverse tining. METHODS : EACP is constructed at two field sites on the SOC research center and Yeo-Ju test road to compare the noise level via close proximity noise measurement. In addition, the noise is measured using two vehicle type based on vehicle speeds of 60, 80, and 100 km/h. RESULTS : The results of noise measurement obtained from the SOC research center are as follows: Porous asphalt pavement 92.8 dB(A), HMA 96. dB(A), transverse tining 100.1 dB(A), and 8 mm EACP 97 dB(A) at a driving speed of 80 km/h. For the case of the Yeo-Ju test road. The noise levels at a driving speed of 80 km/h are as follows: 6 mm EACP, 93.6 dB(A); asphalt grooving pavement, 94.72 dB(A); 8 mm EACP, 95.2 dB(A); NGCS, 95.2 dB(A); transverse tining, 104.1 dB(A). CONCLUSIONS : The result of noise measurement of two sites in the SOC research center and test road shows that the noise level of the 6 mm EAC is lower than that of concrete pavement, such as tining and NGCS, and similar to that of asphalt pavement. In addition, the noise level of the 8 mm EAC is similar to that of the NGCS pavement. The noise reduction effect of the EAC is greater when small-sized coarse aggregates with lower flat and elongation ratios are used.

PURPOSES : The purpose of this study is to estimate the reduction in traffic noise in a double-layered specific porous pavement at roadsides based on variations in traffic volume and driving speed. METHODS : A statistical pass-by (SPB) method was employed in this study to measure noise. Variations in the following parameters were measured: running speed, heavy traffic percentage, and traffic volume. RESULTS : Quantitative analysis revealed that the double-layered porous pavement reduced noise levels by 9.16 dB(A) at a 95% confidence level at the sides of roads. CONCLUSIONS : As a countermeasure of traffic noise, porous pavement has been recommended. This research quantitatively proved that double-layered porous pavement can reduce traffic noise by more than 9.0 dB(A) at roadsides

PURPOSES : The purpose of this study is to estimate the reduction of traffic noise in a double-layered specific porous pavement based on the traffic speed variation. METHODS : The close-proximity method was used in noise measurement, and the running speed was measured at 10 km/h and from 50 to 80 km/h. RESULTS : From the quantitative analysis, it was found that the double-layered porous pavement reduced by 9.4 dB (A) on the average and 9.16 dB (A) at a 95% confidence level. CONCLUSIONS : The use of porous pavements have been recommended to minimize traffic noise. In this study, it is quantitatively demonstrated that the double-layered porous pavement can reduce the traffic noise by more than 9.0 dB(A).

PURPOSES : This paper is aimed at suggesting a novel approach for determining the pavement condition rating based on the tire-surface friction noise using a machine learning algorithm as a low-end pavement condition monitoring system. METHODS : Vehicle on-board type noise measurement system according to the ISO11819-2, and the K-nearest neighbors with dynamic time warping algorithm were applied. The system and algorithm were empirically tested with a field study. RESULTS : The developed AI- and noise-based pavement condition monitoring system demonstrated significantly positive results with a precision 90.8%, recall 84.8%, and f1-score 86.1%. CONCLUSIONS: We herein confirmed that the acoustic property between the tire and road surface can be used for monitoring pavement conditions. It is believed this finding presented a new paradigm for monitoring pavement conditions based on visual information. However, extensive studies focused on the practical application of this method are required.

PURPOSES: This paper presents the noise reduction effect of asphalt concrete pavement using steel slag aggregate. METHODS: Steel slag aggregates induce various mechanical effects because of their high stiffness and specific gravity. It is also known that the noise reduction effect is due to its high specific gravity and porous nature. In this study, the noise reduction in a steel slag asphalt concrete pavement section was measured and analyzed. RESULTS : On average, an asphalt concrete pavement with steel slag reduces road traffic noise by about 2 dB(A). In addition, the analysis of sound pressure levels by frequency showed lower sound pressure levels in steel slag asphalt concrete pavement than general HMA in all frequency ranges (from low to high frequencies). An analysis of the benefits with regard to noise, by assuming a road-traffic noise reduction of 2 dB(A) with asphalt concrete pavement using steel slag, shows that the noise abatement cost approach can save 1.6 million won a year over soundproof wall costs. In addition, the noise damage cost approach results in cost savings (with regard to noise) of between 19 and 60 million won per year depending on the population density. CONCLUSIONS: The use of steel slag aggregate as an asphalt concrete mixture material not only improves the mechanical performance but also has a noise reduction effect. It is expected that the steel slag asphalt concrete pavement can reduce the environmental burden by utilizing resources and provide a safer and more comfortable pavement condition to the road users.

PURPOSES : Exposed aggregate concrete pavements have been adopted in several countries because of their advantages of pavement texture characteristics, which can produce low tire-pavement noise and higher load-carrying capacities. The magnitude of tire-pavement noise greatly depends on the wavelength of pavement texture. The wavelength of exposed aggregate concrete pavement can be controlled with maximum sizing and by controlling the amount of coarse aggregates in the concrete mixture. In this study, the maximum size and the amount of coarse aggregate in the exposed aggregate concrete pavement are investigated to produce equal levels of wavelength in the asphalt pavement. METHODS: A simple method to measure the average wavelength of pavement texture is introduced. Subsequently, the average wavelength of typical asphalt pavement is investigated. A set of mixture designs of exposed aggregate concrete with three maximum-sized coarse aggregates, and three amounts of coarse aggregate are used. The average wavelengths are measured to find the mixture design needed to produce equal levels of wavelength as typical asphalt pavement. RESULTS : With a cement content of 420 kg/m3 and fine aggregate modulus of 30%, the number of exposed aggregates was 48, and the shortest texture depth provided a wavelength of 4.2 mm. According to the number of exposed aggregates, the exposed aggregate concrete pavement could be rendered low-noise, because its wavelength was similar to that of asphalt pavement ranging from 3.9 to 4.4 mm. CONCLUSIONS : Selection of appropriate maximum sizes and the amount of coarse aggregates for exposed aggregate concrete pavement can produce a wavelength texture closely resembling that of asphalt pavement. Therefore, the noise level of exposed aggregate concrete pavement can be reduced with an appropriate maximum size and the amount of coarse aggregates are employed.

PURPOSES : In Korea, concrete pavements with transverse tining, which have excellent skid resistance, have been mainly constructed to secure road bearing capacity and safety. However, transverse tining has higher noise level of approximately 4-5 dB(A) compared with asphalt pavement. As a method to determine low-noise characteristics of concrete pavements, the fine-size exposed aggregate concrete pavement (EACP) has been studied in Korea and abroad. The surface of EACPs consists of exposed coarse aggregates and 2-3 mm removal surface mortar. EACPs have the advantages of maintaining low-noise and adequate skid-resistance levels during the performance period. Although EACPs have been widely studied to reduce noise, quantitative noise analysis with various paving methods has not been performed owing to differences in mixture proportioning, construction conditions, environmental conditions, and measurement methods. Therefore, the purpose of this study is to investigate the low-noise characteristics of fine-size EACPs by comparing noise with various paving methods, including concrete and asphalt pavements. METHODS: In this study, noise data were collected to quantitatively analyze the low-noise characteristics of EACPs compared with various paving methods such as transverse tining, longitudinal tining, SMA, and HMA. RESULTS: The evaluation of the low-noise characteristics of EACPs compared with transverse tining showed that the relative noise of 13 mm EACP with transverse tining was reduced by approximately 2% at 60 km/h, 4% at 80 km/h, and 5% at 100 km/h. The relative noise of 10 mm EACP with transverse tining was reduced to 3%, 7%, and 8% at 50 km/h, 80 km/h, and 100 km/h, respectively. In addition, it was confirmed that the noise of 10 mm EACP was similar to that of asphalt pavement. CONCLUSIONS : It was confirmed that EACP using 10 mm coarse aggregates generates lower noise than that using 13 mm coarse aggregates. Therefore, the use of coarse aggregates smaller than 10 mm needs to be considered to improve the low-noise effect of EACP.

In recent years, there have been applied methods for minimizing noise by adjusting the method of installing soundproof walls, soundproof tunnels, soundproofing rims, environmental facilities, etc., and the shape of the surface texture of tire treads and packaging materials for the purpose of reducing road noise. Low noise pavement methods such as rubber asphalt (CRM), open graded asphalt concrete (OGAC), permeable Friction Courses (PFC), open graded friction courses (OGFC) and porous asphalt have been applied to reduce road noise. Especially, porous pavement is the most widely used low noise pavement with porous structure, which can reduce noise and drain water through continuous void of pavement. On the other hand, porous asphalt pavement has problems such as reduction of noise reduction effect and difficulty of road surface management due to void closing and increase of construction cost. The purpose of this study is to develop ultra-thin layer hot mix asphalt pavement method which maximizes road noise reduction effect by surface micro voids (Recover asphalt pavement) to improve void clogging of present porous pavement method. For this study, maximum size 5mm aggregate and cationic-treated fiber reinforced asphalt modifier (CSM) were used. The Marshall design method was applied grain-size distribution curve was based on SMA mix design. Marshall test, TSR, MMLS3 test and Hamburg test were carried out to evaluate the mechanical properties of ultra -thin layered asphalt pavement method with surface micro voids. Also, the effect of road noise reduction was evaluated through field application in urban area.

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 this study, noise reduction effect of a two-layer porous asphalt pavement was investigated through site measurement and computer simulation. METHODS: To examine noise reduction effect, a 3 km long quiet pavement was installed by removing previous normal pavement, which had a rather low porosity. The studied site was a high-rise apartment building surrounded by the quiet pavement and Seoul ring road with heavy traffic volume, indicating relatively high background noise. RESULTS: The measurement result before and after installing the quiet pavement showed a noise reduction effect of 4.3 dB(A) at a distance of 7.5 m from the road. After validating the accuracy of simulation using SoundPLAN, the reduction in SPL(sound pressure level) at the facades by the quiet pavement was predicted by considering five different road conditions generating traffic noise from each road or in the combination of the quiet pavement and Seoul ring road. In the case of no noise from Seoul ring road, noise reduction at the facades was 4.2 dB(A) on average for 702 housing units. With background noise from Seoul ring road, however, the average SPL decreased to 2.0 dB(A). Regarding subjective response of noise, the number of housing units with a noise reduction of over 3 dB(A) was 229 out of 706 units (approximately 32%). For 77 housing units, the noise reduction was between 1~3 dB(A), while it was less than 1 dB(A) for 400 housing units. CONCLUSIONS: The overall result indicates that the quiet pavement is useful to reduce noise evenly at low and high floors compared to noise barriers, especially in the urban situation where background noise is low.