# Evaluation of the Functional Performance of Paving Materials Based on the Driving Wheel
## 5 Conclusions  
This study developed an acceleration test method for pavement function performance according to the characteristics of environmental and traffic loads based on the Driving Wheel Pavement Analyser (DWPA). The anti-sliding performance, anti-stripping performance, and tire-pavement noise of hot-mix asphalt mixtures--including AC-13, SMA-13, and OGFC-13--and cold-mix mixtures--including MS-1, MS-2, and MS-3 micro-surfacing materials--were evaluated. The following conclusions were drawn.  
The type of material directly affected the basic characteristics and deterioration of the pavement anti-sliding performance. The OGFC-13 mixture exhibited the largest texture depth, which was larger than 1.3 mm at the end of the test. The SMA-13 mixture exhibited the largest BPN, which was larger than 45 at the end of the test. The hot-mix mixtures provided good anti-sliding performances. For the cold-mix mixtures for a thin layer, the texture depth and BPN results indicated that the MS-3 material was the best for providing and maintaining a good anti-sliding performance over a long period.  
The gradation had a direct effect on the anti-stripping performance of the micro-surfacing material; the coarser the gradation, the smaller the mass loss. The mass loss of the MS-1 and MS-3 micro-surfacing materials were 13.5% and 6.7%, respectively, at 70,000 wheel-load repetitions. This may have been because the full-size wheel and heavy axle load would result in a greater shear stress in the material. Therefore, mixtures with fine gradation were easier to deform and strip. The DWPA could effectively evaluate the anti-stripping performance of micro-surfacing mixtures on pavement surfaces.  
OGFC-13 produced the lowest tire-pavement noise, which was less than 60 dB(A), followed by SMA-13. The micro-surfacing mixtures did not help to reduce the tire-pavement noise. The tire-pavement noise of all micro-surfacing materials was larger than that for the hot-mix asphalt mixtures and increased to more than 66 dB(A) by the end of the test. However, for all materials used in this study, the tire-pavement noise increased with increasing wheel repetitions.  
The proposed pavement surface functional performance evaluation method based on the DWPA was able to evaluate the anti-sliding performance, anti-stripping performance, tire-pavement noise, and other pavement surface functional indexes for different types of materials. However, this method still needs to be verified using in situ test data. Furthermore, this method could be used to obtain  
Figure 14: Tire–pavement noise frequency curves of different materials.  
the degradation model of a functional performance index for each material, and provide a basis for decisions regarding pavement maintenance measures in the future.  
Methodology, formal analysis, and writing--original draft preparation: X.C.; supervision and project administration: D.W.; investigation: J.Y. All authors have read and agreed to the published version of the manuscript.  
This work was financially supported by the National Natural Science Foundation of China (grant nos. 51708144).  
The authors declare no conflict of interest.