The whole point of concrete is that it is nearly indestructible an not easily dissolved. A common substance for etching concrete or even dissolving it is hydrochloric acid (HCl) which is sold in hardware stores as muriatic acid. But it is not a "safe" chemical unless precautions are taken. It will cause chemical burns to the skin. The fumes must not be inhaled. It will harm other surfaces with which it may come into contact. It would be best to enlist the assistance of someone who is used to working with this chemical.
Comments
Concrete....
The whole point of concrete is that it is nearly indestructible an not easily dissolved. A common substance for etching concrete or even dissolving it is hydrochloric acid (HCl) which is sold in hardware stores as muriatic acid. But it is not a "safe" chemical unless precautions are taken. It will cause chemical burns to the skin. The fumes must not be inhaled. It will harm other surfaces with which it may come into contact. It would be best to enlist the assistance of someone who is used to working with this chemical.
Use a sledge hammer.