# Properties and Preparation of a New High-Permeability Emulsified Asphalt and Its Modification
## 4 Results and Discussion
### Shear Resistance  
The shear strength of traditional emulsified asphalt, high-permeability emulsified asphalt, and modified high-permeability emulsified asphalt was investigated. The effect of temperature on the interlayer bonding effect was also analyzed using a straight shear test. Nine double-layer composite specimens of each of the three types of emulsified asphalt were tested. The testing temperature was set to 5 \({}^{\circ}\)C, 25 \({}^{\circ}\)C, and 55 \({}^{\circ}\)C. The straight shear test results are shown in Table 14.  
It can be seen from Figure 14 that the shear strength of the adhesive layer is significantly influenced by temperature. The shear strength decreases with the increasing of temperature. However, the shear strength decreasing rate is different across the different temperature zones. When the temperature is low, the emulsification has a certain adhesion. When the temperature is high, the shear strength of the asphalt pavement interlayer decreases significantly because of the low viscidity. If the pavement is subjected to a large traffic load at this time, the shear strength of the binder layer material will not be sufficient to resist the shear stress generated between the layers, resulting in shear damage at the binder layer interface.  
No matter how the temperature changes, the rank of the three materials does not change, i.e., modified high-permeability emulsified asphalt > high-permeability emulsified asphalt > traditional emulsified asphalt. The result indicates that the greater the viscosity of the material itself, the greater the shear strength it can provide. The reason for this  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Types of Asphal** & **Test Temperature** & **Maximum Shear Force (kN)** & **Shear Strength (MPa)** \\ \hline \multirow{3}{*}{Traditional emulsified asphalt} & 5 \({}^{\circ}\)C & 6.731 & 0.857 \\  & 25 \({}^{\circ}\)C & 6.087 & 0.775 \\  & 55 \({}^{\circ}\)C & 2.097 & 0.267 \\ \hline \multirow{3}{*}{Highly permeable emulsified asphalt} & 5 \({}^{\circ}\)C & 9.142 & 1.164 \\  & 25 \({}^{\circ}\)C & 8.215 & 1.046 \\  & 55 \({}^{\circ}\)C & 3.636 & 0.463 \\ \hline \multirow{3}{*}{Modified high-permeability emulsified asphalt} & 5 \({}^{\circ}\)C & 9.880 & 1.258 \\  & 25 \({}^{\circ}\)C & 9.055 & 1.153 \\ \cline{1-1}  & 55 \({}^{\circ}\)C & 4.068 & 0.518 \\ \hline \hline \end{tabular}
\end{table}
Table 14: Shear strength of three types of emulsified asphalt at different temperatures.  
Figure 14: Temperature dependence of shear resistance.  
is that the properties of the material itself affect the performance of the interlayer bond. With the addition of diluents and osmotic agents, the permeability of the highly permeable emulsified bitumen is greatly enhanced, but the highly permeable emulsified bitumen cannot form a bitumen film on the surface of the base that provides sufficient bond strength, resulting in a poor bonding effect. The addition of water-based epoxy resin and curing agents can make the modified emulsified asphalt fully form a certain strength of oil film on the surface of the base, obtaining stronger bonding strength.  
As the temperature rose to 55 \({}^{\circ}\)C, the shear strength of all three adhesive layer materials decreased sharply as the asphalt mixture reached its softening point. The traditional emulsified asphalt decreased the most significantly. The modified high-permeability emulsified asphalt has the best shear strength at high temperatures because the epoxy resin has been completely solidified and is not affected by temperature.