测试条件对橡胶改性沥青黏度的影响分析
2020-07-08丁湛赵浚凯董浩岳向京张静栗培龙陈冲
丁湛 赵浚凯 董浩 岳向京 张静 栗培龙 陈冲



摘要 橡膠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。
关 键 词 橡胶沥青;黏度;控制条件;转速;转子;扭矩
中图分类号 U414.1 文献标志码 A
Effect analysis of test conditions on viscosity for crumb
rubber modified asphalt
DING Zhan1, ZHAO Junkai1, DONG Hao2, YUE Xiangjing1,
ZHANG Jing1, LI Peilong2, CHEN Chong2
(1. School of Water and Environment, Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Changan University, Xian, Shaanxi 710054, China; 2. Key Laboratory of Road Structure & Material Ministry of Transport, Changan University, Xian, Shaanxi 710064, China)
Abstract 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 °C 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 °C viscosity with different test accuracy requiremmenrs are given. The investigation is conducive to the effectiveness and comparability of rubber asphalt viscosity test results.
Key words rubber asphalt; viscosity; control conditions; rotational speed; rotor; torque
黏度是胶粉改性沥青(橡胶沥青)技术性能的最重要指标之一,在工程中需要控制合理的黏度,以确保胶粉改性沥青混合料的拌和、摊铺以及碾压工艺[1]。Brookfield旋转黏度得到了广泛的应用[2],但橡胶沥青旋转黏度的测试条件尚不明确,其测试结果的可比性较差。因此关于橡胶沥青测定条件的研究越来越受到国内外道路领域研究者的关注。
国外橡胶沥青的黏度测试标准[3]中,通常选用SC4-27转子,以20 r/min的转速测定橡胶沥青的旋转黏度,而黏度测试温度的选择主要有:175 ℃旋转黏度、177 ℃旋转黏度、191 ℃ Haake黏度以及190 ℃ Haake黏度。……
