# Effects of Time Content on Road Performance of Low Liquid Limit Clay
## 3 Test Results and Analysis
### Compaction Test  
The relationship curve between dry density and water content is drawn. The horizontal coordinate represents water content and the vertical coordinate represents dry density. The test results are shown in Figures 5-7.  
It can be seen from the figure that the maximum dry density of lime-stabilized soil reaches its peak as the ash content of soil samples A and B increases from 0% to 8%, and reaches its peak when the ash content of soil sample B reaches 6%. Soil sample A decreased from 1.77 g/cm\({}^{3}\) to 1.61 g/cm\({}^{3}\) by 9.03%; soil sample B decreased from 1.75 g/cm\({}^{3}\) to 1.65 g/cm\({}^{3}\) by 5.71%; soil sample C decreased from 1.84 g/cm\({}^{3}\) to 1.73 g/cm\({}^{3}\) by 5.98%; and when lime content exceeded 6%, the maximum dry density decreased less. At the same time, with the increase in the ash mixing rate from 0% to 6%, the optimal water content has basically reached the maximum. Sample A increased from 14.7% to 16.7% (13.6%), sample B increased from 14.5% to 17.2% (18.6%), and sample C increased from 15.1% to 17.4% (15.2%). However, when the ash content increased from 6% to 8%, the improvement effect of increased lime dosage on low liquid limit clay was no longer obvious. The decrease in dry density is small, and the optimal water content is basically unchanged. On the  
Figure 4: Boundary moisture content test results.  
one hand, the water consumption of the improved soil is due to the exchange of Ca\({}^{2+}\) in the lime with other cations on the soil surface. On the other hand, as lime dissolves and hydrates in the soil, the soil is pressed in real time, requiring more water to reduce the friction between particles for optimal compaction. Therefore, with different lime dosage, water consumption is also different, so the change in optimal water content is also different. Therefore, it can be concluded that 6% ash content is a reasonable dosage of improved low liquid limit clay in this area.  
Figure 5: Compaction test results of soil sample **A**.  
Figure 6: \(Cont\).  
Figure 6: Compaction test results of soil sample B.  
Figure 7: Compaction test results of soil sample C.  
It can be seen from the figure that with the increase in compaction times, the CBR values of stabilized soil with different ash content increase. In the case of the same compaction times, the CBR value increased by a large margin before 6%. When the ash content increased again, the increase was not obvious, and the curve tended to be stable. Taking the test with 98 times of compaction as an example, when the ash content increases from 0 to 6%, the CBR value increases from 5.4% to 57.3%. When the ash content increases again, the CBR value does not increase significantly or even decrease to 56.9. It shows that the increase in ash content can significantly improve the water stability of low liquid limit clay. It can be concluded that the ash content of 6% is a reasonable dose for improving low liquid limit clay in this area.  
Longer compaction times improve the CBR value of stabilized soil with varied lime levels, mostly for the following two reasons: When lime first absorbs water from the soil, a lot of heat is emitted as the volume expands, which evaporates the water and improves the soil's quality. Second, some lime reacts with carbon dioxide in the atmosphere to form calcium carbonate, a weakly-bonding material that increases the soil's CBR value and strength to some level.