ABSTRACT
Finished cement is tested for all of the chemical and physical requirements of the standard. However, it is too late at that stage to find that there is a compliance problem and the important testing is carried out at the intermediate stages in the production process. In particular the correct chemistry has to be established at an early stage and this has the advantage that should there be any significant change it can be identified in sufficient time to alert users-the early warning procedures will be discussed later. It means that extensive information is available on the chemistry of main oxides of silicon, calcium, aluminium, iron and magnesium together with alkali metal (sodium and potassium) oxides, sulfur trioxide, chloride, free lime, insoluble residue and loss on ignition. This information is available to users on request. The relevance of some of these may seem vague but to the cement chemist they are invaluable for controlling the reactivity and freshness of the cement.
