PART VIII 



CEMENT 



The following specifications for cement were adopted August 

 16, 1909," as standard by the American Society for Testing 

 Materials. 



GENERAL OBSERVATIONS 



288. (a) These remarks (Pars. 288-293) have been prepared 

 with a view of pointing out the pertinent features of the various 

 requirements and the precautions to be observed in the inter- 

 pretation of the results of the tests. 



(6) The committee would suggest that the acceptance or 

 rejection under these specifications be based on tests made by an 

 experienced person having the proper means for making the 

 tests. 



289. Specific Gravity. Specific gravity is useful in detecting 

 adulteration. The results of tests of specific gravity are not 

 necessarily conclusive as an indication of the quality of a cement, 

 but when in combination with the results of other tests may 

 afford valuable indications. 



290. Fineness. The sieves should be kept thoroughly dry. 



291. Time of Setting. Great care should be exercised to 

 maintain the test pieces under as uniform conditions as possible. 

 A sudden change or wide range of temperature in the room in 

 which the tests are made, a very dry or humid atmosphere, and 

 other irregularities, vitally affect the rate of setting. 



292. Constancy of Volume : 



(a) The tests for constancy of volume are divided into two 

 classes, the first normal, the second accelerated. The 

 latter should be regarded as a precautionary test only, 

 and not infallable. So many conditions enter into the 

 making and interpreting of it that it should be used 

 with extreme care. 



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