Relative Humidity and Drying Shrinkage Performance of Cement Stabilized Macadam Incorporating 0~2.36 mm Recycled Fine Aggregate

In order to improve the application of recycled fine aggregate (RFA) with a particle size of 0~2.36 mm in cement stabilized macadam (CSM) base, 12 groups of CSM specimens with different cement content and 0~2.36 mm RFA content were designed, in cansideration that the drying shrinkage is affected by various complex factors such as cement, aggregate, and humidity, and the existing model cannot accurately evaluate the long-term shrinkage performance. The relative humidity and drying shrinkage of CSM specimens were measured. The relative humidity prediction model was proposed, the drying shrinkage prediction model was revised, and the relationship between relative humidity and drying shrinkage strain was analyzed. Studies have shown that the relative humidity of 0~2.36 mm RFA cement stabilized macadam (CSM-2.36RFA) is related to 0~2.36 mm RFA content and curing period. With the increase of curing period, the relative humidity decreases. The relative humidity increases with the increase of the content of 0~2.36 mm RFA. The drying shrinkage strain of CSM-2.36RFA increases with the increase of curing period and the content of 0~2.36 mm RFA, which is closely related to unconfined compressive strength. Finally, the relative humidity and drying shrinkage strain models of CSM-2.36RFA were obtained, and compared with the experimental values. It was found that the model fit is high. The relationship between relative humidity and drying shrinkage was obtained, and the development of drying shrinkage could be evaluated according to the change in relative humidity.