基于CT技术的水泥稳定碎石微裂程度控制模型

Micro-cracking Degree Control of Cement Stabilized Macadam Based on CT Technology

为探究水泥稳定碎石材料内部细观空隙特征变化对微裂程度的影响,借助CT无损检测技术提取微裂后水泥稳定碎石试件空隙特征参数,采用灰熵关联度探讨水泥稳定碎石空隙参数与微裂程度关联性,建立空隙数量与微裂程度灰色关系模型。结果表明:延长振动时间,面空隙率呈现先增大后减小趋势、微裂程度呈现先增长后降低趋势。微裂后水泥稳定碎石试件相比未微裂试件空隙数量有所增加,且微裂作用对面积在0~0.1 mm^(2)范围内的空隙影响最为显著。圆度在0~0.2范围内空隙占比随振动时间延长逐渐增大,微裂后空隙分形维数均大于未微裂试件,且材料内部空隙形状趋于复杂化。空隙数量与微裂程度关联度最高。基于上述结果建立的微裂程度GM(1,2)预测模型可为水泥稳定碎石微裂技术细观层面研究和应用提供理论参考。

To investigate the influence of the void characteristics of cement stabilized macadam(CSM)on the degree of micro-cracking,the void characteristic parameters of CSM specimens after micro-cracking were extracted with the help of CT nondestructive testing technology.Then,the gray entropy correlation was used to explore the influence of the void parameters of CSM on the degree of micro-cracking.Finally,a gray relationship model between the number of voids and the degree of micro-cracking was established.The results showed that the void ratio of the surface and the degree of micro-cracking both increased then decreased with the extension of vibration time.After micro-cracking,the number of voids in the CSM specimens was higher than the nonmicro-cracking specimens,and the micro-cracking effect had the greatest influence on the voids in the area range of 0-0.1 mm^(2).With the extened vibration time,the percentage of voids in the range of 0-0.2 increased gradually,and the fractal dimension of the voids was larger than the nonmicro-cracking.There is the highest correlation between the degree of micro-cracking and the number of voids.The established GM(1,2)prediction model of the degree of micro-cracking can provide theoretical reference for the research and application of micro-cracking technology for CSM at the fine level.