» Karratha stone is heavy
and dense, and easily meets all requirements for bulk specific gravity
for sandstone-type building stones.
The chemical analysis, showing over 90% silica, suggests that
it should be properly called a Pilbara quartzitic sandstone. There
are no deleterious accessory minerals, and iron content is limited
to the colouring and bedding plane partings. The absorption and
bulk specific gravity tests show a desirable product with low absorption
and high density.
» The compressive strength (95.5MPa) is
high, and well in excess of any standard requirements.
» The modulus rupture (5 MPa) is greater
than that required for a sandstone
(2.1 MPa).
» It is resistant to weak solutions and
temperature cycles.
» When placed in a laboratory furnace and
heated to 600dC, no decomposition or 'splitting' occured, and
no adverse reaction or loss of integrity was detected during heating
or cooling back to room temperature. Obviously no ignition occured,
and therefore there is no evidence to suggest that it poses an
unexpected fire hazard.
Karratha stone, being 2.5 times stronger than concrete and with
0.7% absorption rate, becomes water resistant when laid with a 4:1
mortar
mix. The application of strand ply is recommended to double the
strength of mortar in paving applications. The ratio is one packet to 10m2. |
