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利用驻波管对孔隙率为20%的大孔隙胶粉改性沥青混合料和孔隙率为4%的SBS改性沥青混合料试件进行试验。分别对3cm、4cm、5cm厚度的两种试件按1/3倍频测定吸声系数。试验结果表明:随试件厚度的增加吸声系数增大;大孔隙胶粉改性沥青比SBS改性沥青混合料试件吸声效果明显提高。同时,利用阻尼衰减振动特性测试仪器对两种改性沥青混合料车辙板试件进行轮胎垂直自由落体衰减振动试验。可以看出,与SBS改性沥青混合料相比,胶粉改性沥青混合料试件系统的垂直衰减振动阻尼比D值和损耗因子1/Q值增大约5倍,且自由衰减振动的振幅衰减程度大,即胶粉改性沥青混合料试件具有更好的阻尼特性和降噪功能。因而进一步证明,用大孔隙胶粉改性沥青混合料铺筑路面具有较好的降噪效果。
The use of standing wave tube on the porosity of 20% of the macroporous rubber modified asphalt mixture and the porosity of 4% SBS modified asphalt mixture specimens were tested. Sound absorption coefficient was measured on the two specimens with the thickness of 3cm, 4cm and 5cm by 1/3 octave respectively. The experimental results show that the sound absorption coefficient increases with the increase of the thickness of the specimen; the sound absorption effect of the macroporous rubber modified asphalt is better than that of the SBS modified asphalt mixture specimen. At the same time, two kinds of modified asphalt mixture track plate specimens were tested for the vertical free-fall damping vibration test by using the damping-attenuating vibration characteristic test equipment. It can be seen that compared with the SBS modified asphalt mixture, the powder damping modified asphalt mixture sample system vertical damping vibration damping ratio D value and loss factor 1 / Q value increased about 5 times, and the amplitude of the free-decay vibration A large degree of attenuation, that is, rubber powder modified asphalt mixture specimens have better damping characteristics and noise reduction. Thus further proof, macroporous rubber powder modified asphalt paving has better noise reduction effect.