# A Review of Long-Term Skid Resistance of Asphalt Pavement
## 4 Decay and Prediction of Long-Term Skid Resistance of
### Asphal Pavement
#### Influencing Factors, Decay Law, and Model of Long-Term Skid Resistance of Asphal Pavement
\begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{2}{c}{**Influencing Factors**} & **Influence Mechanism** \\ \hline Mineral grades & \begin{tabular}{c} Under the same material, the coarser the gradation, the harder the compaction, the lower the porosity, the stronger the ability to resist vehicle loads, the smaller the rate of decay of the skid resistance of the pavement, and the smaller the magnitude of the decay [21] \\ \end{tabular} \\ \hline Internal factors & Aggregate types & \begin{tabular}{c} The simpler the apparent texture of the aggregate, the more homogeneous the mineral composition; the smaller the difference in hardness between the matrices, the greater the rate and magnitude of decay of the skid resistance of pavements, and the mixture consisting of aggregates with a richer mineral composition type and large difference in mineral hardness has better durability of skid resistance [63; 113; 123; 124; 125] \\ \end{tabular} \\ \hline Asphalt quality & \begin{tabular}{c} The poorer the quality of asphalt, the poorer the adhesion of mineral granules, the more likely it is to be worn out by driving vehicles; the faster the skid resistance of AP decreases, the greater the decline [68; 126; 127] \\ \end{tabular} \\ \hline Oil-rock ratio & \begin{tabular}{c} Asphalt content is less, cannot be better wrapped aggregates, aggregates are prone to loose off, the faster the decline in skid resistance of the pavement, the larger the amount of asphalt will be gushing out of the road surface, the formation of a light surface; the larger the ratio of oil to stone, the greater the rate of decay of skid resistance of AP and the greater the magnitude of attenuation [63; 122] \\ \end{tabular} \\ \hline Surface contamination & \begin{tabular}{c} Pollutants fall will affect the road surface temperature, humidity, and fill the uneven road surface structure, change the road surface texture structure, at the same time, dust or sand particles gathered on the surface of the particles to form a thin film, reduce the adhesion with asphalt and particles between the internal friction resistance, which accelerates the rate of decay of the skid resistance of AP [13; 88; 128] \\ \end{tabular} \\ \hline Vehicle speed & \begin{tabular}{c} The lower the traveling speed, the greater the maximum damage stress caused by the load and the easier the AP is in a high-stress-ratio state; the fatigue life of the AP reduces the magnitude of the fatigue life of the larger; the higher the speed, the more pronounced the impact of the wheels on the pavement, and the friction role of the more pronounced microstructure of the pavement decreases the faster the roadway skid resistance declines [129] \\ \end{tabular} \\ \hline External factors & \begin{tabular}{c} Tire pressure \\ \end{tabular} & \begin{tabular}{c} The greater the tire pressure, the more serious the AP skid resistance decay, and \\ tread wear will reduce the drainage and water storage capacity of the tread pattern, accelerating the rate of decay of the AP skid resistance [11] \\ \end{tabular} \\ \hline \multirow{4}{*}{Vehicle load} & \begin{tabular}{c} The greater the vehicle load, the faster and greater the rate of decay of the skid resistance of AP, and compared with the overload traffic applied in the middle and late stage of wear, the deterioration rate of the pavement dynamic friction coefficient is faster, and the final value of the friction coefficient is lower when heavy traffic is applied in the early stage [130; 131] \\ \end{tabular} \\ \hline Volume of traffic & \begin{tabular}{c} The more vehicle traffic there is, the faster the AP is abraded and the faster the AP’s skid resistance decays [130] \\ \end{tabular} \\ \hline Vehicle running time & \begin{tabular}{c} The more hours the AP is open to traffic, the faster the rich texture of the asphalt surface as well as the aggregates are compacted and worn out and the faster the skid resistance value of the pavement decreases [132] \\ \end{tabular} \\ \hline \
\begin{tabular}{c} Diurnal temperature \\ difference \\ difference \\ \end{tabular} &
\begin{tabular}{c} Warm day and night temperature differences being large will make the pavement undergo, for a long time, repeated expansion and contraction so that the internal organization of the material structure changes, increasing the degree of aging of AP, accelerating the pavement skid resistance of the decay of speed \\ \end{tabular} \\ \hline \hline \end{tabular}
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