﻿426 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  The 
  standing 
  of 
  an 
  accelerated 
  test 
  of 
  this 
  character 
  is 
  not 
  yet 
  

   satisfactorily 
  established 
  nor 
  has 
  it 
  yet 
  been 
  adopted 
  in 
  standard 
  

   specifications 
  abroad. 
  A 
  test 
  of 
  pats 
  in 
  vapor 
  and 
  after 
  setting 
  

   in 
  water 
  at 
  115° 
  F. 
  which 
  was 
  suggested 
  by 
  the 
  late 
  M» 
  Faiji 
  is 
  

   excellent 
  and 
  entirely 
  free 
  from 
  objection. 
  

  

  With 
  respect 
  to 
  tensile 
  tests 
  of 
  cement 
  the 
  requirements 
  of 
  

   specifications 
  have 
  been 
  thrown 
  into 
  much 
  confusion 
  by 
  the 
  dif- 
  

   ference 
  in 
  strength 
  at 
  short 
  periods 
  between 
  cements 
  treated 
  

   with 
  sulfate 
  of 
  lime 
  and 
  untreated 
  cements. 
  The 
  facts 
  in 
  this 
  

   regard 
  are 
  fully 
  set 
  forth 
  above 
  in 
  dealing 
  with 
  sulfate 
  of 
  lime. 
  

   The 
  value 
  of 
  additions 
  of 
  sulfate 
  resides 
  entirely 
  in 
  regulating 
  

   setting 
  time 
  to 
  make 
  cements 
  more 
  suitable 
  for 
  the 
  uses 
  to 
  which 
  

   they 
  are 
  to 
  be 
  put. 
  The 
  increase 
  in 
  strength 
  incident 
  to 
  the 
  treat- 
  

   ment 
  is 
  without 
  ultimate 
  advantage. 
  Since 
  quick 
  setting 
  cements 
  

   free 
  from 
  sulfate 
  of 
  lime 
  are 
  important 
  for 
  certain 
  uses, 
  it 
  ap- 
  

   pears 
  necessary 
  to 
  distinguish 
  between 
  the 
  two 
  in 
  specifications. 
  

   This 
  is 
  done 
  abroad 
  both 
  in 
  the 
  German 
  and 
  Swiss 
  standard 
  

   specifications 
  (see 
  German 
  and 
  Swiss 
  Normen). 
  For 
  tide-water 
  

   work, 
  for 
  work 
  in 
  wet 
  bottoms, 
  for 
  concrete 
  deposited 
  in 
  water, 
  

   for 
  grout, 
  for 
  work 
  in 
  freezing 
  weather 
  and 
  for 
  rapid 
  construction 
  

   of 
  concrete 
  masonry, 
  quick 
  setting 
  cements 
  are 
  indicated 
  by 
  good 
  

   practice. 
  When 
  used 
  for 
  such 
  purposes, 
  a 
  distinction 
  in 
  test 
  re- 
  

   quirements 
  is 
  desirable. 
  European 
  standards 
  for 
  strength 
  are 
  as 
  

   follows: 
  German 
  Normen 
  slow 
  setting 
  cement, 
  227 
  lb. 
  one 
  to 
  

   three 
  at 
  28 
  days; 
  German 
  Normen 
  quick 
  setting 
  cement, 
  less 
  

   than 
  above; 
  the 
  setting 
  time 
  is 
  to 
  be 
  considered 
  with 
  the 
  strength. 
  

   Swiss 
  Normen 
  slow 
  setting 
  cement, 
  227 
  lb. 
  one 
  to 
  three 
  at 
  2& 
  

   days; 
  Swiss 
  Normen 
  quick 
  setting 
  cement, 
  199 
  lb. 
  one 
  to 
  three 
  

   at 
  28 
  days; 
  French 
  quick 
  setting 
  cement, 
  285 
  lb. 
  neat 
  at 
  seven 
  

   days; 
  French 
  quick 
  setting 
  cement, 
  285 
  lb. 
  neat 
  at 
  seven 
  days; 
  

   French 
  quick 
  setting 
  cement, 
  114 
  lb. 
  one 
  to 
  three 
  at 
  seven 
  days; 
  

   French 
  quick 
  setting 
  cement, 
  498 
  lb. 
  neat 
  at 
  28 
  days; 
  French 
  

   quick 
  setting 
  cement, 
  213 
  lb. 
  one 
  to 
  three 
  at 
  28 
  days. 
  

  

  In 
  America 
  there 
  are 
  no 
  standard 
  test 
  requirements 
  for 
  

   strength 
  of 
  cements 
  and 
  nothing 
  approaching 
  a 
  standard 
  specifi- 
  

   cation. 
  The 
  whole 
  matter 
  is 
  in 
  an 
  extremely 
  unsatisfactory 
  con- 
  

  

  