What Scientific Activities have I did this Summer

During this Summer I was the whole time in Monte Negro. Up in the mountains where there is a lot of rocks i got an idea to start making a little wall of stone. However, to support that big stone wall or just a stone on top of a stone, there has to be either cement or concrete. This was a lot of fun for me, mixing water sand and cement which is almost as like cemestry. to get this hard and supporting substance you have to mix thse 3 substances which are water and cement  and sand. This typeof a substance is a conpund substance which mean that 2 or more elements give one more element which is the third one. How does this form? Easily, the molecules in the whole 3 substances integrate and form the thirs compound substance this is how it works. But if there is any element from these 3 missing then it wont make the concrete nor it will be supportful nor it wont be a conpund substance but it will be just a mixed substance. After wards I used the cement to stick the stones on top of each other, and it will last who knows up to when.