测试条件对橡胶改性沥青黏度的影响分析

Effect analysis of test conditions on viscosity for crumb rubber modified asphalt

橡胶沥青属于典型的非牛顿流体,黏度作为表征橡胶沥青的主要指标,测试条件对其影响很大。Brookfield旋转黏度得到了广泛的应用,但国内外对于橡胶沥青黏度测定转子与转速的选择尚不明确。为了分析测试条件对橡胶沥青黏度的影响,选择不同规格的SC4-21#,SC4-27#转子,分别在10 r/min,20 r/min,50 r/min,100 r/min的不同转速下,测试0%,5%,10%,15%,20%,25%不同胶粉掺量橡胶沥青样品的180℃黏度,同时采用插值法得到橡胶沥青50%扭矩对应的黏度,通过流变学原理分析沥青黏度试验的原理及变化规律。分析了转子与转速对橡胶沥青黏度以及扭矩值的影响,建立了扭矩与橡胶沥青黏度的关系,并推荐了不同测试精度要求的橡胶沥青180℃黏度时的转子和转速,有利于橡胶沥青黏度测试结果的有效性与可比性。

Crumb Rubber Modified Asphalt(CRMA) belongs to typical non-Newtonian fluid. As a major technical performance index of CRMA, the viscosity is greatly affected by the test conditions. Brookfield rotational viscosity has been widely used, however, the choice of rotor and rotational speed for CRMA remains unclear both at home and abroad. To analyze the effect of test conditions on the viscosity of CRMA, different specifications rotors SC4-21# and SC4-27# were selected and the viscosity at 180℃ of CRMA with different rubber contents(0%, 5%, 10%, 15%, 20%, 25%) under different rotational speeds(10 r/min, 20 r/min, 50 r/min, 100 r/min). The corresponding viscosity of 50% torque was obtained by interpolation at the same time, and the test principles and variations of asphalt viscosity were analyzed using rheological principle. This investigation analyzes the influence of rotor and speed on the viscosity and the torque of CRMA during viscosity testing, establishes the relationship between torque and viscosity. The rotor and speed recommendations for rubber asphalt 180 ℃ viscosity with different test accuracy requiremmenrs are given. The investigation is conducive to the effectiveness and comparability of rubber asphalt viscosity test results.