Author Contributions
Conceptualization, L.Y.; methodology, L.Y. and Z.H. software, L.Y.; formal analysis, L.Y. and L.K.; resources, Z.H.; investigation, Z.H. and S.Y.; data curation, L.Y. and D.W.; writing—original draft preparation, S.Y. and L.Y.; writing—review and editing, Z.H. and L.Y.; visualization, S.Y.; supervision, Z.H.; project administration, L.K. and D.W.; funding acquisition, Z.H. and D.W. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Flowchart of preparing BWR.
Figure 1.
Flowchart of preparing BWR.
Figure 2.
Schematic diagram of design and preparation of asphalt blending samples.
Figure 2.
Schematic diagram of design and preparation of asphalt blending samples.
Figure 3.
Brook Dimension Icon AFM: (a) test instrument; (b) test process of tapping mode.
Figure 3.
Brook Dimension Icon AFM: (a) test instrument; (b) test process of tapping mode.
Figure 4.
Image processing flowchart of bee-like structures extraction.
Figure 4.
Image processing flowchart of bee-like structures extraction.
Figure 5.
2D micro-morphology images of VA and AA: (a) VA before blending; (b) AA before blending; (c) VA after blending; (d) AA after blending.
Figure 5.
2D micro-morphology images of VA and AA: (a) VA before blending; (b) AA before blending; (c) VA after blending; (d) AA after blending.
Figure 6.
Statistical results of bee-like structures of VA and AA: (a) Smax; (b) Smean; (c) Stotal; (d) N.
Figure 6.
Statistical results of bee-like structures of VA and AA: (a) Smax; (b) Smean; (c) Stotal; (d) N.
Figure 7.
2D micro-morphology images of VA and 3.5% BWR: (a) VA before blending; (b) 3.5% BWR before blending; (c) VA after blending; (d) 3.5% BWR after blending.
Figure 7.
2D micro-morphology images of VA and 3.5% BWR: (a) VA before blending; (b) 3.5% BWR before blending; (c) VA after blending; (d) 3.5% BWR after blending.
Figure 8.
2D micro-morphology images of VA and 5.5% BWR: (a) VA before blending; (b) 5.5% BWR before blending; (c) VA after blending; (d) 5.5% BWR after blending.
Figure 8.
2D micro-morphology images of VA and 5.5% BWR: (a) VA before blending; (b) 5.5% BWR before blending; (c) VA after blending; (d) 5.5% BWR after blending.
Figure 9.
2D micro-morphology images of VA and 7.5% BWR: (a) VA before blending; (b) 7.5% BWR before blending; (c) VA after blending; (d) 7.5% BWR after blending.
Figure 9.
2D micro-morphology images of VA and 7.5% BWR: (a) VA before blending; (b) 7.5% BWR before blending; (c) VA after blending; (d) 7.5% BWR after blending.
Figure 10.
2D micro-morphology images of VA and 9.5% BWR: (a) VA before blending; (b) 9.5% BWR before blending; (c) VA after blending; (d) 9.5% BWR after blending.
Figure 10.
2D micro-morphology images of VA and 9.5% BWR: (a) VA before blending; (b) 9.5% BWR before blending; (c) VA after blending; (d) 9.5% BWR after blending.
Figure 11.
2D micro-morphology images of VA and 11.5% BWR: (a) VA before blending; (b) 11.5% BWR before blending; (c) VA after blending; (d) 11.5% BWR after blending.
Figure 11.
2D micro-morphology images of VA and 11.5% BWR: (a) VA before blending; (b) 11.5% BWR before blending; (c) VA after blending; (d) 11.5% BWR after blending.
Figure 12.
Statistical results of bee-like structures of VA and RA: (a) Smax; (b) Smean; (c) Stotal; (d) N.
Figure 12.
Statistical results of bee-like structures of VA and RA: (a) Smax; (b) Smean; (c) Stotal; (d) N.
Figure 13.
3D micro-morphology images of VA and AA: (a) VA before blending; (b) AA before blending; (c) VA after blending; (d) AA after blending.
Figure 13.
3D micro-morphology images of VA and AA: (a) VA before blending; (b) AA before blending; (c) VA after blending; (d) AA after blending.
Figure 14.
Statistical results of 3D micro-morphology parameters of VA and AA: (a) Sa; (b) Sq; (c) Sdr; (d) SV.
Figure 14.
Statistical results of 3D micro-morphology parameters of VA and AA: (a) Sa; (b) Sq; (c) Sdr; (d) SV.
Figure 15.
3D micro-morphology images of VA and 3.5% BWR: (a) VA before blending; (b) 3.5% BWR before blending; (c) VA after blending; (d) 3.5% BWR after blending.
Figure 15.
3D micro-morphology images of VA and 3.5% BWR: (a) VA before blending; (b) 3.5% BWR before blending; (c) VA after blending; (d) 3.5% BWR after blending.
Figure 16.
3D micro-morphology images of VA and 5.5% BWR: (a) VA before blending; (b) 5.5% BWR before blending; (c) VA after blending; (d) 5.5% BWR after blending.
Figure 16.
3D micro-morphology images of VA and 5.5% BWR: (a) VA before blending; (b) 5.5% BWR before blending; (c) VA after blending; (d) 5.5% BWR after blending.
Figure 17.
3D micro-morphology images of VA and 7.5% BWR: (a) VA before blending; (b) 7.5% BWR before blending; (c) VA after blending; (d) 7.5% BWR after blending.
Figure 17.
3D micro-morphology images of VA and 7.5% BWR: (a) VA before blending; (b) 7.5% BWR before blending; (c) VA after blending; (d) 7.5% BWR after blending.
Figure 18.
3D micro-morphology images of VA and 9.5% BWR: (a) VA before blending; (b) 9.5% BWR before blending; (c) VA after blending; (d) 9.5% BWR after blending.
Figure 18.
3D micro-morphology images of VA and 9.5% BWR: (a) VA before blending; (b) 9.5% BWR before blending; (c) VA after blending; (d) 9.5% BWR after blending.
Figure 19.
3D micro-morphology images of VA and 11.5% BWR: (a) VA before blending; (b) 11.5% BWR before blending; (c) VA after blending; (d) 11.5% BWR after blending.
Figure 19.
3D micro-morphology images of VA and 11.5% BWR: (a) VA before blending; (b) 11.5% BWR before blending; (c) VA after blending; (d) 11.5% BWR after blending.
Figure 20.
Statistical results of 3D micro-morphology parameters of VA and RA: (a) Sa; (b) Sq; (c) Sdr; (d) SV.
Figure 20.
Statistical results of 3D micro-morphology parameters of VA and RA: (a) Sa; (b) Sq; (c) Sdr; (d) SV.
Figure 21.
Statistical results of 3D micro-morphology parameters of VA and 7.5% BWR under different durations after blending: (a) Sa; (b) Sq; (c) Sdr; (d) SV.
Figure 21.
Statistical results of 3D micro-morphology parameters of VA and 7.5% BWR under different durations after blending: (a) Sa; (b) Sq; (c) Sdr; (d) SV.
Figure 22.
Statistical results of 3D micro-morphology parameters of VA and 7.5% BWR under different blending temperatures: (a) Sa; (b) Sq; (c) Sdr; (d) SV.
Figure 22.
Statistical results of 3D micro-morphology parameters of VA and 7.5% BWR under different blending temperatures: (a) Sa; (b) Sq; (c) Sdr; (d) SV.
Table 1.
Properties of asphalt binders.
Table 1.
Properties of asphalt binders.
Type | Penetration (25 °C, 5 s, 100 g)/0.1 mm | Ductility (5 cm/min, 15 °C)/cm | Softening Point/°C | Viscosity (135 °C)/Pa·s |
---|
VA | 74 | 112 | 48.6 | 0.375 |
AA | 27.6 | 5.3 | 69.1 | 2.674 |
3.5% BWR | 47.5 | 23.2 | 55.9 | 1.029 |
5.5% BWR | 62.3 | 69.6 | 53.4 | 0.558 |
7.5% BWR | 75.1 | 102.7 | 49.7 | 0.389 |
9.5% BWR | 103.7 | 119.2 | 47.4 | 0.301 |
11.5% BWR | 128.4 | 128.6 | 44.9 | 0.273 |
Table 2.
Properties of BWR.
Table 2.
Properties of BWR.
Properties | BWR |
---|
Viscosity, mm2/s (60 °C) | 462 |
Flash point, °C | 245 |
Viscosity ratio, % (after TFOT, 163 °C) | 1.89 |
Wt change, % (after TFOT, 163 °C) | 2.36 |
Density, g/cm−3 (25 °C) | 0.89 |
Table 3.
Regenerative blending degree (RBD-2D) between virgin asphalt and recycled asphalt.
Table 3.
Regenerative blending degree (RBD-2D) between virgin asphalt and recycled asphalt.
Type | RBD-2D/% | Standard Deviation/% |
---|
Based on Smax Value | Based on Smean Value | Based on Stotal Value | Based on N Value | Average Value |
---|
VA + 3.5% BWR | 68.4 | 81.9 | 83.9 | 93.9 | 82.0 | 10.5 |
VA + 5.5% BWR | 97.9 | 92.7 | 96.4 | 90.3 | 94.3 | 3.5 |
VA + 7.5% BWR | 77.5 | 79.3 | 83.8 | 77.9 | 79.6 | 2.9 |
VA + 9.5% BWR | 85.6 | 86.0 | 93.5 | 80.8 | 86.5 | 5.2 |
VA + 11.5% BWR | 51.6 | 76.6 | 73.8 | 83.6 | 71.4 | 13.8 |
Table 4.
Regenerative blending degree (RBD-3D) between virgin asphalt and various recycled asphalts.
Table 4.
Regenerative blending degree (RBD-3D) between virgin asphalt and various recycled asphalts.
Type | RBD-3D/% | Standard Deviation/% |
---|
Based on Sa Value | Based on Sq Value | Based on Sdr Value | Based on SV Value | Average Value |
---|
VA + 3.5% BWR | 78.3 | 89.3 | 93.8 | 98.1 | 89.9 | 8.5 |
VA + 5.5% BWR | 81.8 | 80.4 | 82.3 | 79.7 | 81.1 | 1.2 |
VA + 7.5% BWR | 75.8 | 73.1 | 83.7 | 78.6 | 77.8 | 4.5 |
VA + 9.5% BWR | 65.3 | 72.8 | 69.9 | 77.6 | 71.4 | 5.1 |
VA + 11.5% BWR | 68.7 | 69.2 | 53.1 | 60.7 | 62.9 | 7.6 |
Table 5.
Regenerative blending degree (RBD-3D) between virgin asphalt and 7.5% BWR with different blending durations.
Table 5.
Regenerative blending degree (RBD-3D) between virgin asphalt and 7.5% BWR with different blending durations.
Blending Duration/min | RBD-3D/% | Standard Deviation/% |
---|
Based on Sa Value | Based on Sq Value | Based on Sdr Value | Based on SV Value | Average Value |
---|
20 | 75.8 | 73.1 | 83.7 | 78.6 | 77.8 | 4.5 |
30 | 91.6 | 94.3 | 84.4 | 85.0 | 88.8 | 4.9 |
40 | 60.8 | 64.5 | 53.3 | 57 | 58.9 | 4.8 |
Table 6.
Regenerative blending degree (RBD-3D) between virgin asphalt and 7.5% BWR with different blending temperatures.
Table 6.
Regenerative blending degree (RBD-3D) between virgin asphalt and 7.5% BWR with different blending temperatures.
Blending Temperature/°C | RBD-3D/% | Standard Deviation/% |
---|
Based on Sa Value | Based on Sq Value | Based on Sdr Value | Based on SV Value | Average Value |
---|
120 | 81.9 | 79.9 | 62.9 | 71.2 | 74.0 | 8.7 |
140 | 75.8 | 73.1 | 83.7 | 78.6 | 77.8 | 4.5 |
160 | 82.9 | 90.4 | 78.9 | 90.7 | 85.7 | 5.8 |