ielts writing part 1 cement and concrete making processes The given diagrams illustrate how cement is made and how it is possible to mix it with other components in certain proportions to create a conrete. At the first diagram we can see that it is needed two kind of material to start producing of cement - limestone and clay. They both should be crushed at first and then mixed toghether. After passing the mixer, the mixture of clay and limestone moves to a rotating heater where it is subjected to a firing at high temperature. Following been fired every piece of this mixture is made smaller in size by grinder. As a result of this process we have ready cement, which should be packed in bags and delivered on constructions site. The second diagram shows us a process of making concrete. In comparison with the process of cement creation it is much more simplier. Everything is needed is just to put 15 % of cement, 10% of water and 25 % of sand in a huge concrete mixer, and to add there 50% of small stones whish are called "gravel".