CHAPTER XV 

 CEMENT AND CONCRETE PAINT TESTS 



Damp-proofing and Waterproofing. The decoration and 

 preservation of cement and concrete is a subject which is being 

 given the careful consideration of many technologists on account 

 of the wide usage of cement for structural purposes, and the 

 necessity of properly guarding it against the destructive effects 

 of moisture. 



To obtain with various paints decorative effects, and, at the 

 same time, provide a high degree of damp-proofing, is a process 

 quite distinct from that of water-proofing cement and concrete 

 superstructures. The use, in small percentage, of stearic acid 

 solutions, aluminum stearate, marine animal soaps, and other 

 lime-reacting materials, as a component of concrete while it is 

 being mixed, has been in practice for some time, the resulting 

 mixture being used largely upon base-work subjected to water 

 under high pressure. Although some of the materials used for 

 such purposes actually do give to the concrete a high power of 

 water resistance, the degree of waterproofing to be obtained 

 through the use of many such compounds varies to a wide 

 extent, often interfering with the lime-silica reactions, and ulti- 

 mately affecting the strength of the finished concrete. 



Decorative and Preservative Coatings. The necessity of 

 obtaining suitable paint coatings for cement and concrete sur- 

 faces suggested to the writer a series of tests on paints designed 

 to prevent the destructive action of the lime which, by seepage 

 and other physical action, is brought to the surface, causing 

 saponification of some oil coatings, as well as destruction of color. 

 The tests referred to were carried out during 1908, and although 

 great advances have been made since that time in the preparation 

 of concrete paints, the tests have, nevertheless, afforded informa- 

 tion of a valuable nature as indicating the proper methods to 

 follow in the painting of cement, as well as suitable materials to 

 use in the manufacture of cement paints. The tests, moreover, 

 show the comparative durability of a number of paints typical of 

 those prominent in the market at the time the tests were started. 



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