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Just realised I thought it said 154mm not 54mm. My brain shat a brick and pictured a hole way bigger.
Could literally bang it full of this
https://www.screwfix.com/p/fischer-fis-v-hybrid-mortar-resin-360ml/88507?kpid=88507&ds_kid=92700048793290424&ds_rl=1249413&gclid=CjwKCAiA_f3uBRAmEiwAzPuaM_fAEeLJ2VGDTwPa6AHFmgpLgckLo2SGUNuTGgl1cEmt4ODvcr49QBoClAwQAvD_BwE&gclsrc=aw.dsOr just cut another bit of concrete with the same hole saw and glue that bit in.
Oh. These clinics were built in the 80's so there may be some NHS warning that I've not seen and they are now having problems with.