Progress Toward a Standard Procedure for Point-Counting the Phases in Cement Clinker with Reflected Light Microscopy

Light microscopy can be used to gain insight into the cement manufacturing process and to guide the manufacturer in the production process. By quantitative phase determination, the microscopist can determine how much of each phase is present as well as its morphology.

The ASTM task group C01.23.02 on Microscopical Methods, under the C01.23 subcommittee on Compositional Analysis, has been developing a Standard practice for point counting of cement microstructure using reflected light microscopy. The task group is continuing with round robin testing. The inter-laboratory study results for one SRM indicate that counting 3 000 points is a good compromise between effort and accuracy. Intra-laboratory precision showed a need for a uniform level of training; therefore, a video tape has been made for training microscopists.