Research on Performance of Recycled Mixture with High RAP Content from Central Plant Hot Recycling and Evaluation Method of Its Durability

Abstract

Based on pavement maintenance project of the national road, a series of laboratory tests were conducted to investigate the road performance of recycled mixtures with different RAP content by wheel tracking test, immersing Marshall test, freeze-thaw splitting test and low temperature bending test. During these tests, virgin mixture without RAP is used as a control group. Furthermore, the durability of recycled mixture was verified by a new test method by which the impact-freeze-thaw damage degree can be obtained. On the basis of laboratory experiments, three types of trial sections have been successfully paved on the national road. The results show that the performance of recycled mixture with 30% RAP is better while recycled mixture with 50% RAP can also satisfy the existing standards by adding the recycling agent and reinforcing agent. The new test method is efficient to distinguish the durability difference between different mixtures. The performance of these recycled trial sections meet the existing standards, and recycled mixture with high RAP content can be used in national road project on a large-scale.