沥青路面裂缝密封胶的低温应力松弛评价指标

Low-Temperature Stress Relaxation Evaluation Index of Asphalt Pavement Crack Sealants

摘要:

为了评价沥青路面裂缝密封胶的低温应力松弛能力，选择4种加热型密封胶和2种有机硅密封胶，参照交通行业标准进行低温拉伸试验，达到50%应变量后进行应力松弛试验，采用三参数固体模型拟合应力松弛试验数据。结果显示，三参数固体模型可以理想地拟合密封胶的粘弹性力学行为，模型的两个粘弹性特征参数：最大松弛比例和松弛时间，可以评价不同密封胶的应力松弛能力，但拟合过程较为复杂。定义了松弛指数，该指标与采用粘弹性特征参数的评价结果一致，实用性和可操作性较强，可作为密封胶行业标准低温性能评价的一个补充指标。

Abstract:

Four kinds of hot-applied sealants and two kinds of silicone sealants are tested by low-temperature extension test according to the transport industry standard to evaluate the low-temperature stress relaxation performance of the asphalt pavement crack sealants. The stress relaxation tests are started when the strain of the sealants is up to 50%. The three-parameter solid model is used to analyze the test data. The results show that the viscoelastic behavior of the sealants could be modeled very well by the three-parameter solid model, and two parameters of the solid model, maximum relaxation rate and relaxation time, which represent the viscoelastic characteristics of the sealants, has the potential of evaluating the stress relaxation performance for different sealants, though the fitting process is very complex. Furthermore, a relaxation index is defined in this work. The evaluation results with this index have no big difference with the results from the viscoelastic parameters. However, the relaxation index is more feasible and easy to use. The relaxation index can be used as a supplementary indicator for the low-temperature performance evaluation of the sealants on the basis of the transport industry standard.