﻿CLAYS 
  OF 
  NEW 
  YORK 
  Y49 
  

  

  4 
  The 
  bricks 
  should 
  be 
  soaked 
  for 
  48 
  hours, 
  completely 
  im- 
  

   mersed, 
  in 
  pure 
  water. 
  

  

  5 
  After 
  soaking, 
  and 
  before 
  weighing, 
  the 
  bricks 
  must 
  be 
  wiped 
  

   dry 
  from 
  surplus 
  water. 
  

  

  6 
  The 
  difference 
  in 
  weight 
  must 
  be 
  determined 
  on 
  scales 
  sensi- 
  

   tive 
  to 
  1 
  gram. 
  

  

  7 
  The 
  increase 
  in 
  weight 
  due 
  to 
  water 
  absorbed 
  shall 
  be 
  calcu- 
  

   lated 
  in 
  percentage 
  of 
  the 
  initial 
  dry 
  weight. 
  

  

  The 
  commission 
  which 
  drew 
  up 
  these 
  specifications 
  considers 
  

   that 
  any 
  brick 
  which 
  will 
  satisfy 
  the 
  requirements 
  of 
  reasonable 
  

   mechanical 
  tests 
  will 
  not 
  absorb 
  sufficient 
  water 
  to 
  prove 
  injurious 
  

   to 
  it 
  in 
  service, 
  and 
  that 
  for 
  such 
  brick 
  the 
  absorption 
  test 
  should 
  

   be 
  abandoned 
  as 
  unnecessary, 
  if 
  not 
  actually 
  misleading. 
  

  

  Specifications 
  for 
  cross-breaking 
  tests 
  

  

  1 
  Support 
  the 
  brick 
  on 
  edge, 
  or 
  as 
  laid 
  in 
  pavement, 
  on 
  hard- 
  

   ened 
  steel 
  knife 
  edges, 
  rounded 
  longitudinally 
  to 
  a 
  radius 
  of 
  12 
  

   inches 
  and 
  transversely 
  to 
  a 
  radius 
  of 
  one 
  eighth 
  of 
  an 
  inch, 
  and 
  

   bolted 
  in 
  position 
  so 
  as 
  to 
  secure 
  a 
  span 
  of 
  6 
  inches. 
  

  

  2 
  Apply 
  the 
  load 
  to 
  the 
  middle 
  of 
  the 
  top 
  face 
  through 
  a 
  hard- 
  

   ened 
  steel 
  knife 
  edge, 
  straight 
  longitudinally 
  and 
  rounded 
  trans- 
  

   versely 
  to 
  a 
  radius 
  of 
  yV 
  inch. 
  

  

  3 
  Apply 
  the 
  load 
  at 
  a 
  uniform 
  rate 
  of 
  increase 
  till 
  fracture 
  

   ensues. 
  

  

  4 
  Compute 
  the 
  modulus 
  of 
  rupture 
  by 
  the 
  formula 
  

  

  -__3jw_l 
  

   TblP' 
  

   in 
  which 
  

  

  f^ 
  modulus 
  of 
  rupture 
  in 
  pounds 
  a 
  square 
  inch 
  

   w 
  = 
  total 
  breaking 
  load 
  in 
  pounds 
  

   1 
  = 
  length 
  of 
  span 
  in 
  inches 
  = 
  6 
  

   b= 
  breadth 
  of 
  brick 
  in 
  inches 
  

   d 
  = 
  depth 
  of 
  brick 
  in 
  inches 
  

  

  5 
  Samples 
  for 
  test 
  must 
  be 
  free 
  from 
  all 
  visible 
  irregularities 
  

  

  