深度降解橡胶沥青胶浆黏弹特性试验

Experimental on viscoelastic properties of highly degraded rubber modified asphalt cement

为了对深度降解橡胶沥青胶浆体系进行黏弹特性分析并对其相态结构定量评估,采用双螺杆挤出机对传统橡胶粉进行深度降解,结合动态剪切流变学分析传统橡胶沥青胶浆与深度降解橡胶沥青胶浆特性,借鉴多分散聚合物Han曲线原理对橡胶沥青胶浆体系相态结构进行定量判断。通过常规检测及应变扫描、温度扫描、频率扫描等动态剪切流变试验,从黏温指数、相位角、复数模量、车辙因子和损耗因子等指标评价2种橡胶沥青胶浆体系黏弹特性,定性分析深度降解橡胶粉对橡胶沥青胶浆体系黏弹特性的影响,并对其相态结构性能进行研究。研究结果表明:采取感温指数作为橡胶沥青胶浆体系温度敏感性能的评价指标,当橡胶粉掺量(质量分数,下同)为20%时,橡胶沥青胶浆体系确定的最佳粉胶比为1.0;不同粉胶比条件下橡胶沥青胶浆黏弹特性区间出现平移扩张,相同粉胶比条件下,经过深度降解的橡胶沥青胶浆体系较传统橡胶沥青胶浆体系应变区间缩小;通过温度扫描及频率扫描试验得出深度降解橡胶沥青胶浆体系的黏弹特性较好;在相同温度、相同粉胶比条件下,深度降解橡胶沥青胶浆体系的复数剪切黏度较小,呈现出较好的流动特性;温度扫描条件下,当粉胶比为1.0时,深度降解橡胶沥青胶浆体系Han曲线斜率最大。

To analyze the viscoelastic characteristics and quantitatively evaluate the phase structure of the highly degraded rubber asphalt slurry system,the traditional rubber powder was deeply degraded by twin-screw extruder.Combined with dynamic shear rheology,the characteristics of traditional rubber asphalt slurry and the characteristics of deep degradation of rubber asphalt slurry were analyzed.The phase structure of rubber asphalt slurry system was quantitatively determined by reference to the principle of multi-dispersed polymer Han curve.The viscoelastic properties of two kinds of rubber asphalt slurry system were evaluated by sticky temperature index,the phase angle,complexe modulus,the rut factor and loss factor index from conventional detection and conventional dynamic shear rheological tests,strain scanning,temperature scanning and frequency scanning.The influence of deep degradation rubber powder on the viscoelastic properties of rubber asphalt paste was analyzed qualitatively and the phase structure perfoemance were studied.The results show that the temperature sensitivity index is used as the evaluation index for the temperature sensitivity of rubber asphalt cement system.When the content(mass fraction,same below)of rubber powder is 20%,the optimum powder to slurry ratio of rubber asphalt mortar system is 1.0.The viscoelastic properties of rubber asphalt mastic under different powder-cement ratio conditions appear translational expansion.The strain range of rubber asphalt mastic system after deep degradation is smaller than that of traditional rubber asphalt mastic system under the same condition.Through temperature scanning and frequency scanning test,it is concluded that the deep degradation rubber asphalt mortar system has good viscoelastic property.Under the same temperature and powder to slurry ratio,the complex shear viscosity of the deep degradation rubber asphalt mortar system is small and presents good flow characteristics.When the powder to slurry ratio is 1.0,the slope of the Han curve of the deep degraded rubber asphalt mortar system is the highest under the condition of temperature scanning.2 tabs,16 figs,30 refs.