In this study, an experimental analysis of noise reduction in road traffic by applying the Micro Grooving technique to concrete highway pavements is explored. Initiated in 1984 to address the aging and damage issues observed in South Korea's concrete highways, Micro Grooving is known for creating fine grooves on the cement pavement surface to increase friction, prevent hydroplaning, and inhibit ice formation, while reducing vehicle friction noise by 3∼5dB(A). It is determined from noise measurement results that the application of the Micro Grooving method can be expected to reduce roadside noise and enhance the safety of drivers' driving experience.
The object of this paper is to estimation of noise reduction effect of road noise by operating condition due to tire noise regulation. A prepare the countermeasure of the noise reduction according to collect tire/road noise data under various influencing factors by using the tire test method. To accomplish the object : A automotive is used as a test platform to test tire/road noise by changing different types of tires and using the On-Board Sound Intensity test system. The influence of inflation pressure, road, load, speed and pattern type on tire/road noise is compared and analyzed. At the same time, the mechanism of tire/road noise is analyzed, which provides an experimental basis for tire noise reduction.
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.
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).
It is known that air pollutants such as fine dust and exhaust gas from vehicles are harmful to human health. In particular, the black carbon emitted by vehicles is known to cause a large number of premature deaths. This study analyzed the effect of a noise barrier on the inflow amount of black carbon from a nearby high traffic road to a school area, using numerical analysis performed at two elementary schools. Also, the correlation between the noise barrier’s shape, height and the inflow amount of black carbon was assessed. As a result, it was found that the higher the noise barrier, the lower the inflow amount of black carbon observed at the school A. However, the inflow amount of black carbon at school B was not greatly influenced by the height of the noise barrier. The inflow amount of black carbon at the schools could be changed not only by the height of the noise barrier, but also by the shape, height and position of the noise barrier and the school building.
PURPOSES: The purpose of this study is about noise which is generated from roads and is consist of irregular frequency variation from low frequency to various band. The existing methods of noise reduction are sound barrier that uses insulation material and absorbing material or have applied passive technology of noise reduction by devices. The total frequency band is needed to apply active noise control.
METHODS: In this study applies to the field of road traffic environment, signal processing controller and various analog signal input/output, the amplifier module is based on parallel-core embedded processor designed. DSP performs the control algorithm of the road traffic noise. Noise sources in the open space performance of evaluation were applied. In this study, controller of active signal processor was designed based on the module of audio input/output and main controller of embedded process. The controller of active signal processor operates noise reduction algorithm and performance tests of noise reduction in inside and outside environment were executed.
RESULTS : The signal processing controller with OMAP-L137 parallel-core processors as the center, DSP processors in the active control operations dealt with quickly. To maximize the operation speed of an object and ARM processor is external function keys and display for functions and evaluating the performance management system was designed for the purpose of the interface. Therefore the reduction of road traffic noise has established an electronic controller-based noise reduction.
CONCLUSIONS : It is shown that noise reduction is effective in the case of pour tonal sound and complex tonal sound below 500Hz by appling to Fx-LMS.