Did a quick google on patents in this area and there are MANY! And, Thomas Edison even had concrete patents http://edison.rutgers.edu/cemepats.htm http://edison

Did a quick google on patents in this area and there are MANY! And, Thomas Edison even had concrete patents http://edison.rutgers.edu/cemepats.htm http://edison.rutgers.edu/cemepats.htm https://www.google.com/search?&q=concrete+patent&oq=concrete+patent https://www.google.com/search?&q=concrete+patent&oq=concrete...