稻壳灰复合深度降解橡胶沥青流变特性

Evaluation of Rheological Characteristics of Rice Hull Ash Compound Deeply-degraded Rubber Asphalt

本研究优选掺量分别为0%、3%、6%、9%及12%的稻壳灰与20%掺量的深度降解橡胶沥青进行复合改性,然后进行了旋转黏度试验(RV)、动态剪切流变仪试验(DSR)、多应力蠕变恢复试验(MSCR)、弯曲梁流变仪试验(BBR)及荧光显微镜试验(FM),评价了其黏滞性能、高温性能、抵抗不可恢复变形性能、低温性能及微观特性。研究表明,随稻壳灰掺量的增加,稻壳灰复合深度降解橡胶沥青的黏度、高温性能及抵抗不可恢复变形能力提高,在180℃下的黏度均满足施工和易性要求。但相比掺量,温度对其黏度的影响敏感性更大;同时稻壳灰的掺入,可以提高其疲劳性能、低温性能及应力敏感性,改善深度降解橡胶沥青的内部微观结构,随掺量的增加,稻壳灰复合深度降解橡胶沥青由柔韧的“网络”结构向更稳定的“板体”结构转变,其中疲劳性能最佳掺量为6%,低温性能最佳掺量为3%。

In order to explore the rheological properties of rice hull ash composite deep-degraded rubber asphalt,the rice husk ash of 0%,3%,6%,9%,12%and 20%of deep-degraded rubber asphalt was selected for composite modification,and then the rotational viscosity test(RV),dynamic shear rheometer test(DSR),multi-stress creep recovery test(MSCR),bending beam rheometer test(BBR)and fluorescence microscope test(FM)were carried out to evaluate the viscosity performance,high temperature performance,irreversible deformation resistance,low temperature performance and microscopic characteristics.The analysis of the test results showed that with the increase of the rice hull ash content,the viscosity,high temperature performance and irreversible deformation resistance of the rice hull ash composite deeply-degraded rubber asphalt continued to increase,and the viscosity at 180℃all met the requirements of construction and workability.However,compared with the dosage,the temperature is more sensitive to the effect of its viscosity.Simultaneously,the mixing of a certain amount of rice hull ash can improve its fatigue performance,low temperature performance and the stress sensitivity to a certain extent,improves the internal microstructure of deep-degraded rubber asphalt.With the increase of the content of rice husk ash,the structure of rice husk ash composite deep-degraded rubber asphalt changes from flexible“network”structure to more stable“plate”structure.The optimal dosage for fatigue performance is 6%,the optimal dosage for low temperature performance is 3%.