基于180s劲度模量的低温开裂指数预测

Prediction of low-temperature cracking index based on 180s stiffness modulus

提出了一种通过材料性能测试,预测5~10年状况下沥青路面实际开裂的方法。依托开裂指数同沥青材料低温性能的关系,利用CAM模型(一种数学模型)拟合得到了5类常用沥青的180 s劲度模量值,预测并提出了PAV(压力老化)状态下各类沥青的开裂指数。通过数据分析,验证了该种模拟方式预测的准确性。借助长吉高速实地芯样开裂情况调研,验证CI值(低温开裂指数)对沥青路面实际开裂水平的预测效果。结果表明,CAM模型下得到的沥青梁180 s模量计算方法简单,数据置信度高,预测得到的SBS改性沥青开裂指数与路面实际开裂水平一致,证明了利用沥青材料性能预测路面实际抗裂能力这一方法的可行性。依据规范提法,给出了五类北方常用沥青的CI值参考区间。

This paper proposes a method to predict the actual cracking of the asphalt pavement under the condition of 5 to 10 years through the material performance test.Based on the relationship between the cracking index and the low-temperature performance of asphalt materials,the 180 s stiffness modulus values of 5 types of commonly used asphalts are obtained by fitting the CAM model,and the cracking indexes of various asphalts under the PAV state are predicted and proposed.The accuracy of this simulation method is verified by actual data.The investigation on the cracking situation of the core samples of the Changji Expressway supports the prediction effect of the CI value on the actual cracking level of the asphalt pavement.The results show that the 180 s modulus calculation method of the asphalt beam obtained under the CAM model is simple and the data reliability is high.The predicted SBS modified asphalt cracking index is consistent with the actual cracking level of the pavement,which also proves the feasibility of the use of material performance to predict the actual crack resistance of the asphalt pavement.According to the standard practice,the CI values of five types of asphalt commonly used in northern China are given.