稻壳灰改性沥青混合料性能研究及路面结构动力响应分析

Study on Performance of Rice Husk Ash Modified Asphalt Mixture and Dynamic Response Analysis of Pavement Structure

农副产品与废弃物成为环境污染的主要原因,为了减少其对环境造成的破坏及避免资源的浪费,本研究在活性稻壳灰及稻壳灰改性沥青的制备工艺研究的基础上,开展稻壳灰改性沥青混合料服役性能的研究。为此,通过分形理论对矿料级配设计加以优化分析,在保证沥青混合料性能可靠性的同时,研究了级配对混合料体积参数的影响;采用路面性能试验对比分析改性前后沥青混合料路面性能的差异性,并结合移动荷载作用下的三维有限元模型对混合料的路面结构进行相应分析,探寻稻壳灰改性沥青混合料的服役机理。结果表明:分形理论可以较好地描述分形维数值与混合料体积参数之间的关联性,所建立的预估方程模型可以较好地对混合料的体积参数进行预测;稻壳灰改性后,混合料的高温性能及水稳定性得到改善,虽然其低温性能有所衰减,但仍满足使用要求;有限元模型表明改性稻壳灰对基质沥青混合料的服役性能具有显著的改善效果,可以用来较好地量化分析沥青混合料服役时的各向异性。

Agricultural products and waste become the main cause of environmental pollution.To reduce the damage to the environment and avoid the waste of resources,this study was conducted to investigate the service performance of rice husk ash modified asphalt mixtures based on the preparation process of active rice husk ash and rice husk ash modified asphalt.For this,the orthogonal test was used to develop the rice husk ash modified asphalt with excellent performance,and the effect of the preparation process on the physical properties of the modified asphalt was investigated.The fractal theory was used to optimize the gradation design of mineral materials,and the influence of gradation on the volume parameters of asphalt mixture was studied while the reliability of performance ratio was ensured.Pavement performance test was used to analyze the difference of pavement performance of asphalt mixture before and after modification,and the pavement structure of asphalt mixture was analyzed with three-dimensional finite element model under moving load,so as to explore the service mechanism of rice husk ash modified asphalt mixture.The results showed that the fractal theory can better describe the correlation between the fractal dimensional values and the volume parameters of the mixture,and the prediction equation model was established to well predict the volume parameters of the mixture.The high-temperature performance and water stability of the mixture were improved after the modification of rice husk ash,although its low-temperature performance was attenuated,it still met the requirements.The finite element model showed that the modification of rice husk ash greatly improved the service performance of the matrix asphalt mixture,which can be used to better quantify the anisotropy of the asphalt mixture in service.