this is just a idea , what if we could have a furnace that we could smelt down the old tin cans into scrap metal
then after we have upgraded the furnace to level 2 you then have the ability to smelt down the scrap metal and then forge it into reinforcement material.

any way thats just a idea , feel free to add onto it. but i claim full rights if it get implemented XD

i like this idea

but reinforcement material shouldn't be too easy to get, otherwise player will spam mud fences everywhere

It depends on how much scrap metal you need to create one reinforcing material.
I think this can be balanced, so it won't be too easy. I like it.