President/Chief Technologist, Kiln Technology, Inc., Allentown, PA
Strength is one of the most important properties of cement. When major strength variations occur, control actions are usually taken to mitigate the problem. The control actions taken can mask exactly when the deviations occurred and can hide their magnitude in addition to obscuring their source. It is often possible, however, to remove the effect of a known variable so that the source(s) of the problem can be located.
If strength values for individual production samples are divided by their fineness, the resulting values of strength per unit fineness (suitably indexed for readability) can be graphed versus time to determine exactly when strength deviations occurred (unrelated to fineness) and their magnitude. An example from an actual production problem illustrates the method and shows how the transformed data can be used to demonstrate the probable sources of the strength variations. Erratum to this paper appears in 17(1).
Paper ID: CCA10295J