粉煤灰漂珠道路声屏障材料的吸声性能研究

The sound absorption of road noise barrier material made of fly-ash cenospheres

轻集料多孔混凝土因其轻质、多孔、耐候性好的特点,可应用在交通噪声控制领域。试验选用热电厂固废粉煤灰漂珠作为集料,水泥作为胶凝材料制备了一种新型轻集料多孔混凝土,可用作道路声屏障的吸声材料。通过实验表征,探究了成型压力、骨胶比2个因素对于试样吸声性能的影响。同时使用Horoshenkov&Swift模型对材料曲折度因子与流阻进行反演求解,探究成型条件对其影响。结果表明,随着压力的提升,试件吸声的峰值频率向低频移动,峰值处的吸声系数下降;随着骨胶比的提升,试件吸声的峰值频率向高频移动,峰值处的吸声系数提高;反演运算的计算结果表明拟合优度R^(2)>0.8,具有可信性。在0.9骨胶比的条件下,成型压力与曲折度因子和流阻呈正相关;在0.2 MPa的加压强度下,骨胶比与曲折度因子呈负相关。

Light-aggregate porous concrete can be applied to traffic noise control because of its light weight,porosity and good weather resistance.This experiment developed a new light-aggregate porous concrete using fly-ash cenospheres,namely solid wastes from thermal power plants,as aggregate and cement as cementitious material.It could be applied to the sound absorption material of the road noise barrier.Impacts of two factors,namely molding pressure and aggregate-to-cement ratio,on the acoustic performance were investigated through experimental characterization.Horoshenkov&Swift model was also used to inverse calculate the tortuosity and flow resistance of the material to investigate the effect of molding conditions on them.The results show that with the increase of pressure,the first peak frequency of sound absorption of the specimen shifts to low frequency and the absorption coefficient at the peak decreases.With the rise of aggregate-to-cement ratio,the peak frequency of sound absorption shifts to high frequency,and the absorption coefficient at the peak increases.The calculation results of the inverse computation show that the fitting degree R^(2)>0.8,which is credible.Under the condition of 0.9 aggregate-to-cement ratio,the forming pressure is positively correlated with the tortuosity and flow resistance.While under the forming pressure of 0.2 MPa,the aggregate-to-cement ratio is negatively correlated with the curvature factor.