Evaluation of the Failure Behavior of Cement Grouted Asphalt Mixture with Different Grouting Materials and Asphalt Binders

Cement grouted asphalt mixture (CGAM) is developed with both flexible and rigid materials. It can be used to enhance the anti-rutting performance and increase the load bearing capacity of the pavement. However, the influences of cementitious grouting materials and asphalt binders on CGAM’s failure behavior have not been fully understood yet. In this study, the indirect tension (IDT) test, the compression test and the semi-circular bending (SCB) test were conducted to evaluate the strength and cracking resistances of CGAM with different cementitious grouting materials and asphalt binders. With different binders and bitumen/aggregate ratios, two kinds of cementitious grouting materials and six asphalt mixture skeletons were used in mixture design. IDT test results showed that the indirect tensile strength of CGAM would decrease as the bitumen/aggregate ratio increases. The addition of additives would also lower CGAM’s IDT strength. CGAM samples with high-strength cementitious grouting materials exhibited a higher strength than those with early strength cementitious grouting materials. However, there were not any distinct differences in the CGAM’s compression strength when different cementitious grouting materials and asphalt binders were used. SCB results showed that increasing the asphalt binder content and using additives can enhance the cracking resistance of CGAM. CGAM with high-strength cementitious grouting materials would crack more rapidly due to its rigidity. In the end, a two-way ANOVA was conducted on the results of the three tests. It is found that the type of grouting materials impacts the failure behavior of CGAM more significantly than the influences of the asphalt binder content. The addition of additives would also affect the failure of different CGAM samples. The findings in this paper can provide guidance for designing CGAM with better pavement performance.