UndergroundQ I am an engineering technologist working on a landslide project where shotcrete had been applied to stabilize the sandstone head scarp at the crest of the slope. The shotcrete was applied in 1998. After a recent inspection, it was noted that the surface of the shotcrete had some cracking in some sections. How can this be repaired? Can the cracks simply be filled with a grout/mortar mixture of some sort or do the cracked sections have to be removed entirely and shotcrete be reapplied?
Shotcrete can and has been used to overlay previously installed shotcrete or concrete that has cracked over time. It would be advisable that you engage an engineer knowledgeable in geotechnical engineering and concrete properties to formalize a solution. It is important that the cause of the cracks be determined and adequate reinforcing be designed to ensure that the cracks do not propagate through the overlaid shotcrete.