Study On Noise Reduction Characteristics Of Continuous Gradation Rubber Particles Asphalt Pavement

Traffic noise is an important source of the environmental noise pollution. With the development of the automobile industry, the proportion of the tire / road noise in traffic noise is larger and larger, which has been generally concerned by people. Study shows that it has significant effect on noise reduction that choosing suitable road materials and pavement structure. Drawing on relevant research results at home and abroad, this paper researches mixing process, forming process and road performance of big rubber particle's asphalt mixture about continuous gradation. And then, noise reduction'characteristic is researched emphatically by vibration damping test of tyre, hammering vibration test of pavement, iterative load test, noise absorption test, combining wavelet technology and finite element analysis. The main work and achievements are as follows:1. Rubber particles'content and bitumen aggregate ratio are the main two factors which effect physical and mechanical properties of big rubber particle's asphalt mixture about continuous gradation, and rubber particles'content has more influence than bitumen aggregate ratio. In the possess of mixing and forming process, the most important technical factors are throwing order of raw materials, forming temperature and striking times.2. For big rubber particles'asphalt mixture of continuous gradation, the best mixing and forming process is as following: the mixing time is seventy five seconds after mixing asphalt. forty seconds is used after mixing rubber particles and mixing temperature is one hundred and seventy degrees centigrade. Forming mixture is divided into twice: mixing temperature is one hundred and seventy degrees centigrade for the first time and hitting time is fifty four on every surface; the second mixing temperature is eighty degrees centigrade and hitting time is twenty six on every surface.3. Mixing big rubber particles into continuous gradation asphalt pavement is feasible.It has better high-temperature stability and low-temperature crack resistance, has worse water stability than common bituminous pavement, and the more rubber particles mixed into pavement, the more obvious the trend becomes.4. Rubber particles'asphalt pavement has better capability of vibration reduction and sound absorption than common asphalt pavement. The more rubber particles content, the larger the maximum aggregate size and size of rubber particles, the better pavement's capability of vibration reduction and noise reduction. In addition, the noise absorption capability of rubber particles asphalt pavement is mainly affected by the content of rubber particles and gradation type. Comprehensive consideration, however, rubber particles asphalt pavement is based mainly vibration reduction.5. It can effectively depress vibration strength of vehicle tyre when rolling and much more when turn around if mixing big rubber particles into asphalt pavement, making vibration energy flow from "low frequency" to"intermediate frequency "and "high frequency". Content of rubber particles, rubber particle size and maximal size of aggregate can effect vibrational peak acceleration of vehicle tyre in the different frequency bands.6. Capability of rubber particles asphalt pavement for sound absorption reduction is primarily determinated by pavement'void, and is hardly affected by structural depth.When the vehicle tyre hits pavement skipply, activation to center of impact will falls if thickness of pavement increases. Following direction of travel, dropping height of tyre has special influence on inspiring with noise of tyre. Pavement which has fixed content of rubber particles has finite damping ability to tyre stress. Once exceeding limit of damping ability, rubber particles asphalt pavement will lose superiority of noise reduction by vibration reduction.