Building Materials, Third Edition

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where
S = split tensile strength (N/mm^2 )
W = applied load (N)
d = diameter of specimen (mm), and
L = length of specimen (mm)
The average of three results separately for each condition should be reported as split tensile
strength of the sample. In case any test piece gives a value of as much as 15 per cent below the
average, it should be examined for defects and if found defective the test piece should be rejected.

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The test is carried out either in Jhonson shear tool (Fig. 3.12) or Dutton punching shear device
(Fig. 3.13). Three test pieces are used for conducting the test in each of the saturated and dry
condition.
Test piece for use in Jhonson shear tool should be bars 50 × 50 mm in section and not less
than 100 mm in length and that for use with the Dutton punching shear device should be slabs
30 mm in thickness, 100 mm in width and not less than 100 mm in length.

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