Characteristics of dry shrinkage and temperature shrinkage of cement-stabilized steel slag

- Paper presents characteristics of dry shrinkage and temperature shrinkage of CSS and CSM.
- The cement content and gradation types affect the dry shrinkage and temperature shrinkage deformation of CSS and CSM.
- The hydration of CSS is more obvious than that of CSM.
- Using CSS instead of CSM as base course materials can effectively reduce the shrinkage deformation.

The objective of the present study was to investigate the characteristics of dry shrinkage and temperature shrinkage of cement-stabilized steel slag (CSS). The steel slag was intended to be utilized to replace the macadam in cement-stabilized base course to reduce dry shrinkage and temperature shrinkage of semi-rigid base materials. Dry shrinkage and temperature shrinkage tests were performed to analyze the water loss rate, dry shrinkage strain, dry shrinkage coefficient and temperature shrinkage strain of CSS and cement-stabilized macadam (CSM) as functions of time, cement content and gradation types of the material. The water loss rate of CSS increased with the rise in time, and then tended to be flat on about 10th days. The hygroscopicity of coarse gradation CSS was larger than those of intermediate gradation and fine gradation CSS. With the same gradation, the more the cement content was, the greater the water loss rate was. It was suggested that the cement content of CSS should not be more than 4%, which can obviously reduce the dry shrinkage strain. Compared with CSM, CSS with rational adjustment of gradation owned a smaller dry shrinkage strain and would not produce a larger temperature shrinkage strain. It is feasible to replace the base macadam with waste steel slag, which is beneficial to improve the characteristics of dry shrinkage and temperature shrinkage of semi-rigid base material and utilization of waste steel slag. This paper aims to provide a solid theoretical foundation to popularize the wide utilization of CSS in engineering applications.