基于均匀性设计的水泥稳定碎石宏观性能及微观机理

Macroscopic Properties and Microscopic Mechanism of Cement Stabilized Macadam Based on Uniform Design

从水泥稳定碎石多级分散体系和非匀质特性的角度,对水泥稳定碎石组成结构和收缩开裂机理进行分析,得到了抗裂水泥稳定碎石的理想结构状态,进而提出基于均匀性设计的分层次设计思想和两阶段设计方法,并对设计得到的混合料力学性能和微观机理进行研究。通过SEM-EDS和显微硬度,从界面特性、微观生成物角度对界面过渡区进行了分析。结果表明,采用两阶段设计较规范设计方法得到的水泥稳定碎石,改善了混合料均匀性和界面状态,微观结构相对致密,缺陷较少,力学性能也得到不同程度改善,界面过渡区厚度减小25%~29%,平均显微硬度提高了13. 8%,揭示了基于均匀性设计得到的水泥稳定碎石性能改善的微观机理。

From the perspective of multi-stage dispersion system of cement stabilized macadam and non-homogeneous properties,the structure and shrinkage cracking mechanism of cement stabilized macadam are analyzed,and the ideal structural state of crack-resistant cement stabilized macadam is obtained. The hierarchical design idea and the two-stage design method are studied,and the mechanical properties and microscopic mechanism of the designed mixture carried out. The interface transition zone was analyzed from the interface characteristics and microscopic products by SEM-EDS and microhardness. The results show that the cement stabilized macadam obtained by the two-stage design method is better than that by the standard design method,which improves the homogeneity and interfacial state of the mixture,has relatively compact microstructure,fewer defects,and improves the mechanical properties in varying degrees. The thickness of the interfacial transition zone decreases by 25% ~ 29%,and the average microhardness increases by 13. 8%. which reveals the microscopic mechanism of the performance improvement of cement stabilized macadam based on uniformity design.