Fluidity control of grouting materials in grouting pavement based on grouting saturation degree

In order to determine the requirements of grouting asphalt concrete(GAC) on the fluidity of grouting materials(GM), the flow time and diffusion diameter of different GMs of different cement net paste systems were tested by conical barrel method and truncated cone die method, and the mechanical properties of GM specimens were characterized by flexural and compressive strength tests. The top, middle and bottom slice images of GAC specimens were analyzed by digital image processing technology, the calculated grouting saturation degree of specimens at different depths was obtained, and the correlation between flow performance indexes and grouting saturation degree were analyzed combined with grey correlation. The regression equations between grouting saturation degree and flow performance indexes were established, and the flow performance requirements of cement net paste system GM were determined, which were verified by grouting test. The results show that increasing the water cement ratio and the content of super plasticizer can improve the fluidity of GM, but increasing the water cement ratio can greatly reduce the mechanical properties. Compared with the conical barrel method, the correlation between the truncated cone die method and grouting saturation degree is higher. In order to ensure the uniformity and effectiveness of GAC grouting effect at different depths, the overall grouting saturation degree of GAC with 25% air voids content of matrix mixture needs to exceed 85%,the grouting saturation degrees of GAC at different depths are basically the same. The flow time of cement net paste system GM is less than 11.3 s or its diffusion diameter is greater than 27.2 cm. © 2023 Central South University of Technology. All rights reserved.