One alternative we have considered to increase the strength of our pozzolan cement is to add grinding aid (strength-enhancer).But during our first run, the blank sample exhibited more strength in the lab test compared to cement with grinding aid. Can the grinding aid will really boost strength to a greater degree? What grinding aids you can suggest for this purpose? Currently we have 28-day strength of 23 MPa but our objective is to reach 30MPa.

The interactions of grinding aids and quality conditioners are complex and you have to conduct trials to find the optimum additive and addition rate. The specialists in this area are Grace. If they cannot help you then perhaps Mapei? I think your wish to increase the 28 day strength by almost 40 per cent is too ambitious and that no additive can do this. You must continue with your trials to find the best possible additive and addition rate.

We always have problems to get masonry cement with 95 per cent passing the 200 mesh in a mill with an O-sepa separator. We have high Blaine numbers but low in fineness. Do you have any solution please?

I think you have a problem with different grindability for the clinker and limestone fractions of your masonry cement. The limestone is preferentially grinding and giving you the high Blaine, however the harder clinker remains coarse and is the reason for the high residue. The best solution would be to separately grind the limestone and blend with OPC to create the masonry cement.