By increasing surface area the cement classified as finer cement and you can get the mean size by SEM

Thank you ever so much for your answer and support.

I guess I made my question in a wrong way. We are developing a research about sustainable UHPC. The second part of the work involves experimental dosages and there we are going to use SEM and Laser to get the D50. The dosages will be designed using Statistical Mixture Design, but we are going to have into consideration A&A modified as a reference (q=0,23 because we are going to use big amount of binder, maximum size of aggregate 0,5mm and intensive mixer) . The start points for the SDM are the output of the first part, which involves the statistical analysis of 2000 dosages from several articles published in the last 20 years. Our problem here is that in the articles most of the time the information of the cementitious an fine materials is given through the blaine fineness or the BET specific surface. And other times for the average particle size. Our intention is to homogenize this data to a single measure (in our case to D50).

It is possible to get a reasonable value of D50 through some correlation from the BET and Blaine values?

Thank you again for your help and support

Joaquin Abellan-Garcia The 'D50' is a median particle size not a mean. The relation between SSA and the Sauter Mean Diameter (Surface Area Moment Mean) is D[3,2] = 6/SSA with the appropriate units. See, for example:

https://www.researchgate.net/post/What_is_the_relation_between_blaine_number_and_specific_surface_measured_by_laser_particle_sizer

and the attachment.

For packing, see this webinar (free registration required):

In pursuit of perfect packing

https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W151021PerfectPacking.html