Strength and shrinkage properties of cement stabilized macadam bases incorporating 0-2.36 millimetre recycled fine aggregate

Recycled aggregates can effectively replace natural aggregates in the cement stabilized layer of pavement, but the impact of 0-2.36 millimetre recycled fine aggregates (RFA) on the performance of cement stabilized macadam (CSM) is unclear. This paper was aimed at evaluating the impact of 0-2.36 mm RFA on mechanical properties and shrinkage performance of CSM incorporating 0-2.36 mm RFA (CSM-2.36RFA). The unconfined compressive strength (UCS), indirect tensile strength (ITS), drying shrinkage and temperature shrinkage were tested. Test results showed that the impact of 0-2.36 mm RFA on mechanical properties of CSM-2.36RFA were closely related to cement content. When the cement content was 4%, the UCS and ITS decreased with increasing 0-2.36 mm RFA content. However, the UCS and ITS increased first and then decreased with the increase of 0-2.36 mm RFA content containing 5% or 6% cement. The drying shrinkage performance of CSM-2.36RFA was deteriorated with increasing 0-2.36 mm RFA content. The cement content is the most important negative factor affecting the temperature shrinkage performance of CSM-2.36RFA, while the 0-2.36 mm RFA content has a little effect on the temperature shrinkage performance. Fuzzy matrix theory was used to evaluate various mix proportions, 6% cement and 30% 0-2.36 mm RFA had the best mechanical properties and shrinkage performances for CSM2.36RFA.