Abstract: The setting time of shotcrete and the adaptability of materials except cement and accelerator cannot be determined according to the setting time of cement slurry mixed with accelerator based on the existing specifications. The application effect of these accelerators in the field is poor, and shotcrete block and large rebound phenomena often occur. Accordingly, the laboratory test and field construction are employed to analyze the accelerator checking method and setting time control limit, which address the problem that the test object of cement net slurry method is relatively single. The results show that the application of shotcrete setting time test method and setting time limit can accurately judge the adaptability of accelerator setting time, and the test results are consistent with the actual use of the site, which can effectively guide the site construction, improve the technical benefit of shotcrete, save costs, improve construction efficiency, and provide support for the safe operation.

Key words: shotcrete, setting time, drop block analysis, accelerator adaptability, optimal accelerator amount