基于龚帕斯模型的改性乳化沥青胶浆黏度与沥青破乳评价

针对改性乳化沥青破乳时间难以量化评价的不足, 采用不同类型的细集料与改性乳化沥青制备了改性乳化沥青胶浆, 运用龚帕斯模型分析了其黏度随时间的变化规律, 并建立了准确评价改性乳化沥青破乳的数学模型。研究结果表明: 改性乳化沥青胶浆初始黏度较低, 随沥青破乳时间的增大而不断增大, 最后趋于稳定; 当集料粒径相同时, 花岗岩改性乳化沥青胶浆的黏度最大, 玄武岩胶浆的黏度次之, 而石灰岩胶浆的黏度最小, 但黏度增长速率基本相同, 符合生长曲线的特征; 龚帕斯模型可以较好地反映胶浆黏度随时间的变化规律, 计算值与实测值的最大相对误差小于15%; 当根据龚帕斯模型建立的沥青破乳评价指标值为0.97~1.00时, 胶浆黏度变化趋于平稳, 此时改性乳化沥青已经完全破乳; 反之, 也可以根据黏度试验结果计算龚帕斯模型参数, 预测改性乳化沥青破乳时间。

Evaluation of asphalt demulsification and viscosity of modified asphalt emulsion mortar based on Gompertz model

Aiming at the deficiency of quantitative evaluation on the demulsification time of modified asphalt emulsion, the different types of fine aggregates were added into modified asphalt emulsions to prepare the asphalt mortars, Gompertz model was applied to analyze the variation laws of mortar viscosity with time, and a mathematic model was established to quantitatively evaluate the demulsification of modified asphalt emulsion. Analysis result indicates that the initial viscosity of modified asphalt emulsion mortar is low, but increases with the demulsification time and finally tends to be stable. With the same size aggregates, the granite asphalt mortar has the biggest viscosity, the basalt asphalt mortar has smaller viscosity, and the limestone asphalt mortar has the smallest viscosity. However, the increasing rates of viscosity are basically same for the different types of asphalt mortars, and conform to the characteristic of growth function. Gompertz model can be used to reflect the variation laws of viscosity with time because the biggest relative error between the calculated and measured values is lower than 15%. Then, an evaluation index was proposed based on Gompertz model to evaluate the demulsification, and the viscosity variation of asphalt mortar is stable when the index value ranges from 0.97 to 1.00. At the moment, the modified asphalt completes the demulsification. On the other hand, the measured viscosity can be used to calculate the parameters of Gompertz model, and to predict the required time to complete the demulsification for the modified asphalt emulsion.