Were in the process of building a handicap ramp. The ramp area is all located on concrete that was already done long ago. The only parts were anchoring into the cement is the posts closest to the door. We drilled the holes and when we tried to get the bolts inplace most of them went in fine but I applied to much pressure to one of them and snapped the bolt head right off and the other one would only go so far before it just woulden't sink in any further and it woulden't back out either.
Needless to say it's not SUPER sturdy but it isn't wobbly right now either and it will for sure not be wobbly when the rest of the ramp is together. But we were thinking since they didn't anchor in as well as we would have hoped. We have concrete on hand since were getting ready to install a fence. Would it be a feasable option to put up a small frame around the 4x4's and filling it with concrete so that the anchor hardware and 4x4 get cemented as 1 semi big block? I would think it would adhere to the already poured concrete that way as well and make it more sturdy....
Post a picture.
No one here know what it is your using to attach these post to the concrete.
You say the bolt head snapped off but what were you inserting the bolt into? http://strongtie.com/products/connectors/ABW.asp
A post base like this would have worked