Certain directions in several cement specifications appear to
mandate a fixed mass of cement for (lab) trial batches. If a
specific mass of material is called for, it may be more or less
than the intended volume of material, setting up a potential
conflict in the directions. The mass of cement for mixing trial
batches in the lab was always intended to be dependent on the
bag weight of the material, as this can vary from one product to
another. To correct this confusion, remove the statements that
set an exact mass for a given volume of plastic cement and
replace this with a statement to obtain bulk density from the
bag or material supplier in order to determine the correct mass
of cement for trial batches. Because the calculation example is
non-mandatory information, delete the note from the body of the
text and place it in a new appendix along with explanatory
language. plaster; plastic cement; portland cement-based
plaster; stucco; Citing ASTM Standards [Back to Top]