Page 23 - HIGHWAY ENGINEERING LABORATORY_FLIP BUILDER

4.0 DETAILED PROCEDURE : POLISHED STONE VALUE (PSV)

REFERENCE
WORK PROCESS
DOCUMENT
the scale. Ensure that the track of the slider is parallel to the

long edge of the specimen across the sliding distance.
• Use the following procedure to ensure that the rubber slider is
correctly conditioned.
• NOTE It is possible to reverse the slider to make use of both
edges.

a) Maintain a stock of Criggion specimens for calibration
purposes. These shall be made from stone from Criggion
Quarry and shall be made and polished as in an actual

determination. When tested they shall yield a value in the
range58 to66. Record the values and air-dry the specimens
and store them in a sealed container for future use.
b) Before using a new slider, swing it five times over the dry

surface of a polished Criggion specimen following with a
further 20 swings on its wetted surface. Keep the Criggion
specimen used for this purpose apart from the Criggion
calibration specimens tested in it may be used repeatedly

provided its value (when wet) does not fall below55.
c) Before measuring the set of specimens polished on each test
run, check the performance of the slider by testing a
Criggion calibration specimen. Record the resulting value.

Additional polishing through repeated testing yields
progressively lower values and the control shall be discarded
when its value falls below 57. A new control shall then be
drawn from the stock. If a check value is more than 2 units

lower (or one unit higher) than the last recorded value for
the control, discontinue testing and rectify any fault in the
instrument or its operation or due to changes in the slider. It is
recommended that more than one slider be kept in use to

help differentiate between a faulty slider and a defective
instrument.
d) Discard any slider that develops excessive burring and
scoring through prolonged use.

Higway Engineering Laboratory page 10