Shrinkage, Fatigue and Microstructural Characteristics of Vibration Mixing Cement Stabilized Macadam

The cement stabilized macadam (CSM) is widely used in pavement bases in China and different countries, but it is prone to shrinkage and fatigue cracking, resulting in a decrease in the service life and quality of the pavement. The resistance to shrinkage and fatigue cracking substantially affects the durability of CSM base. The objective of this study is to investigate the effect of the vibration mixing technology on the cracking resistance and microstructural characteristics of vibration mixing CSM. The drying shrinkage, temperature shrinkage, and fatigue tests of the vibration mixing CSM and traditional two-cylinder continuous mixing (TTCM) CSM were carried out to analyze their shrinkage strain and fatigue life. The microstructure of the vibration mixing was inspected by the scanning electron microscopy (SEM). The results showed that the dry and temperature shrinkage performance as well as fatigue performance of the cement stabilized macadam can be improved by the utilization of vibration mixing technology. The long-term shrinkage properties of the vibrating mixing cement stabilized macadam were also better than those of traditional mixing. The temperature shrinkage coefficient of CSM was greatly decreased with the vibration mixing technology, which was more obvious from - 25 to - 10 & DEG;C. The fatigue life of the CSM had improved with the vibration mixing technology. The possible reason for the improved shrinkage performance and fatigue characteristics is that the mechanism of the vibration mixing promotes for better distribution of the hydration products, and a three-dimensional network structure is formed in the CSM. In short, the durability and service life of the pavement can be improved with the vibration mixing technology.