You are reading a single comment by @Chalfie and its replies.
Click here to read the full conversation.
Chalfie-
Epoxy was used in coal mines to fix roofing bolts when I was a lad. Admittedly these were several feet long: the resin and hardener came in polythene tubes that were inserted the full depth of the hole then mixed by spinning the bolt with a pneumatic borer. It worked well enough in the '70s (there's a lot of 'roof' to hold up when you're over half a mile down)- I can only imagine things have improved since then?
MrE
Epoxy resin is a good option for anchoring bolts, comes in a tube, squeeze it into the hole and plunge a bolt in, stuck solid in seconds. You need to clean the dust out of the hole properly first though. Never had much luck with expanding bolts. Also 2 is better than 1.