After their first year of study, the two Cal Poly professors wrote the NPIRC Phase 1 report, for the NPC, suggesting that aggressive water was the primary cause of “spot etching” in their plaster test pools… which of course, is what the NPC wanted.
Six months later, however, the same professors (along with a petrographer) wrote a separate report (regarding the same Phase 1 study), and presented it to the International Cement Microscopy Association (ICMA), but did not make that same claim.
Instead, they stated that the specific cause(s) of “spotting” could not be determined due to poor water maintenance and record keeping! They also did not refer to the spotting problem as spot “etching,” but instead, referred to it as spot “alteration” and described the spots as being “soft.”
Additionally, the professors acknowledged (as does the cement/concrete industry) that improper and excessive finishing techniques, high calcium chloride content, and uneven moisture content can lead to excessive shrinkage, cracking, discoloration, permeability, and to a wide range of progressive deterioration mechanisms. That is quite a change in opinion from the NPC report to the ICMA report. Why?
Since NPC leaders are unable to refute the evidence that the study is flawed, and needing a way to avoid further discussion, they often claim that everything was unanimously approved by the NPIRC committee. But even that claim is not true.
There were members of the committee that disagreed with the first protocol and conclusions. Lee Wikstrom, Ph.D., saw problems with the study and voiced them at their meetings. The NPC stopped notifying him of future meetings and was dropped from the committee. (They have also removed industry people from other committees before). Apparently, that is one way to control the outcome of research conclusions and suggest unanimity.
In our next post, we will illustrate how the NPC and Cal Poly professors must not have understood the difference between an etched plaster surface (caused by aggressive water), and a deteriorated surface caused by improper material and plastering practices.