[Ferro List] more Tom's crud testings

[tom rapenske]

Jon,
   
  Ya, at Uwe's prompting I checked the spring water back in Nov. All the previous photos I've posted in Nov and Dec were ones that I used distilled water in as a thorough test of the spring water. Please note that in the latest testings the #4 sample used distilled water again as a further test. It seems likely at this point that the spring water is playing no part in the problem.
   
  Unrelatedly, your past dummy-slap posts re compatible thermal coefficients of different metals and materials in cementitious composites have been super interesting in that subsequent relevant research has, once again, reinforced the crucial task of FCers to pay attention to microcracking in the design and repair of FC structures. Although ignored in recent postings about after-the-fact dome leakages, off-the-back-of-the-truck accidents, and waterproof coatings, microcracking, both inherent and load caused, is often much more important to appropriate impermeability than porosity! Very numerous research papers/ concrete and FC technologists/ PVA literatures, etc have all long pointed out that the mostly invisible (under ~200 microns?) microcracking that is potentially an underlying causation of leakage/ poor durability only gets worse with the passage of time (as opposed to more stable porosity volumes) as various stresses (incompatible thermal coefficiencies being only
 one) occur in our structures. Applying inappropriate waterproof coatings to block porosity can be way too bandaidish to solve real problem. Sometimes all that fundamental info gets swallowed up in engineering gobbledygook language, but the essential fact seems to indeed be that microcracking design is of great importance in the impermeability, durability, strength, and serviceability of most FC. No? Perhaps Richard or TP or you could lend their expertise to my clumsy commentary and provide easy links to fascinating FC/concrete microcracking literature that is understandable to us interested peons doing small potatoes projects?
   
  Tom
  
Jon Sherbeck <sherbeck at doitnow.com> wrote:
  Tom,
I have been following your investigation, and have to wonder if the common 
denominator to the problem is the spring water. Maybe you should try a test 
with some distilled water. Jon 


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