Tapcons not holding

Hi - I am installing tapcons into cement around a pool - they are holding up my 4x4 posts for my fence. I have had issues with the taps not holding - I have seen a post about filling the hole with wood - can someone tell me more about how to do this?

Thanks
Smitty

Typically filling a hole with wood is done in wood by taking toothpicks and jamming them in the hole and cutting them flush. In concrete fill the hole with treated lumber splitters and run new screws in. Another option would be to fill the existing holes with something like this: http://www.dap.com/dap-products-ph/concrete-waterproof-filler-sealant/ and drill new holes with the proper bit and use new Tapcons.

Great thanks for the help

Edited my reply but its basicly the same lol.

you could use conical anchors in the holes then try to re-tighen, make sure you are using correct bit size and not seem holes. usually you get a good bite the first time but don’t run the screw in and out it will eventually strip out.