Abstract: In order to develop efficient grouting repair materials for cracks in existing lining structures in complex geological
environments such as mines and tunnels,and to realize the utilization of solid waste,it is proposed to use slag and fly ash
as precursors,water glass and sodium hydroxide as alkali activators to prepare solid waste-based repair agents. Based on the orthogonal
experimental design,the response law of the working performance and mechanical properties of the repair slurry was
studied under the changes of alkali activator modulus,precursor ratio,water-binder ratio and alkali activator content,and the ideal
ratio of the material was recommended according to the requirements of the repair operation. The results show that the precursor
ratio has the most significant effect on the performance indexes of the repaired slurry except fluidity. Increasing the slag
content in the precursor can significantly shorten the setting time of the slurry and increase its 28 d compressive strength. The
effect of water-binder ratio on the fluidity of slurry is more prominent than the other three factors. In addition,increasing the amount
of alkali activator can also effectively improve the fluidity. The optimum ratio of crack repair materials is recommended:
the modulus of alkali activator is 1. 2 or 1. 4,the ratio of fly ash / slag is 7∶3,the ratio of water to binder is 0. 5,and the content
of alkali activator is 40%. The research results provide a theoretical basis for the application of green repair materials in infrastructure
such as mines and tunnels,especially in the repair scene of concrete lining structure.

Key words: engineering material,formulation design,experimental research,working performance,comprehensive balance
method