Porosity and wear resistance in stone flooring tiles

A sorptivity test and a permeability test were used as an assessment of the degree of porosity of stone flooring tiles, where there was particular int erest in the surface characteristics. A good correlation was obtained betwe en the two tests; the sorptivity is preferred since it is the easier to per form and could be extended to assess the characteristics of full-sized tile s. A Taber Abraser was used to compare the likely wear of the stones. Assessme nt was by weight loss and by groove depth, measured by both a depth microme ter and a laser beam profile meter. Good agreement was achieved among all t he wear measurement methods. The laser beam is the least preferred method d ue to the equipment cost and availability. Mohs' mineralogical scratch meth od was used to assess hardness, which is possibly related logarithmically t o the Taber wear. The stone types were two granites and two marbles in common use in Hong Kon g. One granite had the best properties from all measurements. The other gra nite and one of the marbles had similar properties, while the remaining mar ble showed distinctly inferior properties. Flooring specification limits co uld perhaps be set above those achieved on the poorer marble, but more work is required to set definitive limits. Stone flooring physical property lim its do not appear to be specified in Hong Kong, and elsewhere performance s pecifications seem to be at best limited.