For spalling fix, it can be relevant to remove all unsound concrete unless sturdy substrate is reached

https://damientxvt749.urbanvellum.com/posts/concrete-spall-repair-around-penetrations-details-that-prevent-leaks

For spalling restoration, it's helpful to cast off all unsound concrete till cast substrate is reached, then fresh metallic to a defined trendy previously making use of coatings or patch fabrics.