Investigation of warm mix epoxy asphalt compaction with gyratory compactor and charge coupled photoelectric imaging

摘要

The object of this paper is to investigate the compaction characteristics of warm mix epoxy asphalt concrete with the aid of the viscosity test, gyratory compaction test, and two-dimensional image analysis. The compactability energy required from initial densification to 97% Gmm for epoxy asphalt concrete (CDIE) was proposed from the gyration compaction curve to evaluate the effect of curing temperature, curing time, and compaction effort on material workability. Microstructural indices in the sectional images of warm mix epoxy asphalt concrete specimen were obtained considering the same conditions with compactability energy. Results show that the viscosity of epoxy asphalt binder and mastic both increase over the curing time. The higher temperature is, the faster viscosity will increase. On the basis of compactability energy, a specific range of curing time exists in which warm mix epoxy asphalt concrete can be easily compacted. Two-dimensional images obtained from charge-coupled device photoelectric scanner indicate that aggregate orientation, aggregate distribution, aggregate contact, and proximity asphalt mortar film thickness are all affected by compaction effort and curing time. The overall test results show that Stribeck tribology theory could describe the internal friction change of warm mix epoxy asphalt concrete during the gyration compaction test. Based on the internal friction results, the epoxy asphalt mastic viscosity ranging from 100 to 200 Pa.s is recommended as the optimal for the compaction of warm mix epoxy asphalt concrete. (C) 2020 Elsevier Ltd. All rights reserved.