摘要
粘度是评价道路沥青粘结特性的重要技术指标,也是条件性指标,不同测试方法得出粘度指标差异极大。基于沥青在路面结构中受力状态,对基质沥青、SBS、高强度、高粘度改性沥青等12种道路沥青60℃零剪切粘度、毛细管粘度进行比较研究,并对零剪切粘度测试方法进行简化。试验与分析表明:高粘度改性沥青在第一牛顿区共同区域范围内与沥青在路面结构中所受的剪切速率水平一致,零剪切粘度可以较为合理地表征沥青在路面结构中的粘结特性;高粘度改性沥青毛细管粘度存在虚高现象,无法有效表征高粘度沥青路用粘度特性,而基质沥青毛细管粘度对应的剪切速率在第一牛顿区域范围内,可作为零剪切粘度的替代指标,对基质沥青粘度性能进行评价。此外,建议利用剪切速率扫描试验进行零剪切粘度测试,取10-3～10-2s-1范围内测量粘度均值为零剪切粘度。
Viscosity is a key evaluating indictor for asphalt binder in road engineering, but it is an indicator in given condition, its value depends on test method. Shear rate suffered by asphalt in asphalt pavement is calculated. 12 kinds of asphalt including A -70 base asphalt, SBS modified asphalt, high -modulus asphalt and high - viscosity modified asphalt are selected, and their capillary viscosity and zero shear viscosity at 60 Celsius degree are compared. The results show that, the first Newtonian region of high - viscosity modified asphalt where the viscosity reached the zero shear viscosity agrees with the shear rate range suffered by asphalt in asphalt pavement, and zero shear viscosity could reasonably reflect the viscosity characteristics of high - viscosity modified asphalt in asphalt pavement. Capillary viscosity of high viscosity asphalt has the illusion that the viscosity is high, and it could not reflect the viscosity properties of high - viscosity modified asphalt in pavement structure. Shear rate corresponding with capillary viscosity of A -70 base asphalt is in the range of the first Newtonian region, and thus capillary viscosity could be used as a substitute indicator for zero shear viscosity for base asphalt viscosity evaluating. Besides, the average of measured viscosity values obtained by shear rate scanning tests in flow state, which is corresponding with the shear rate range of 10-3 - 10-2 s-1 is suggested as zero shear viscosity.
出处
《石油沥青》
2010年第3期15-21,共7页
Petroleum Asphalt
关键词
道路沥青
零剪切粘度
毛细管粘度
比较研究
简化测试方法
paving asphalt
zero shear viscosity
capillary viscosity
comparative research
simplified test method
