Page 43 - Haddonstone

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Appendix 1- Flatness of Plane

The equipment required to perform this test shall be:

• Straight edge of equal or greater length to the maximum dimension over which the
flatness is to be measured or 1.5 m whichever is the lesser.

• Feeler gauges (two sets).

Method

Concave Surfaces: Place the straight edge on the surface of the item to be tested.
Insert a feeler gauge blade between the straight edge and the surface of the cast stone.
Measure the deviation from the straight and compare with the value given in 8.4.4.

Convex Surfaces: Place the straight edge on the surface of the item to be tested.
Insert two feeler gauge blades of identical size, one at each end of the straight edge such
that contact is made between the feeler gauge blades the straight edge and the stone.
Measure the deviation from the straight and compare with the value given in 8.4.4.
NB The deviation from the straight is the thickness of one feeler blade not the sum of both.

Appendix 2 – Capilliary Absorption Test

Measure the visual face of each product by suitable means and record the area of each in
square millimetres to the nearest 10mm2. Record as A1, A2, A3.

At not less than 14 days old, dry the three products in a well ventilated oven or ovens

at 70±5°C for at least 72h and allow to cool to room temperature 15-25°C in an air-tight

enclosure. Weigh and record the mass of each unit to the nearest 0.1% of the product
weight and record as W1, W2, W3.

Place each product, supported on suitable spacer devices, into a try and fill with cold
water so that the visual face under test is under a maintained 5±1mm head of water. After
10±0.5min, remove each product; remove excess water with a damp rag and within 30s of
the removal, reweigh and record the masses as above, Record as X1, X2, X3.

Calculate the capillary absorption C1, in mg/mm2, to the nearest 0.1 mg/mm2:

C1 = 1 00 0 (X1 – W1)
A1

Similarly repeat the calculation for the other samples C2 and C3 substituting the relevant
values of X and W.

Finally calculate the mean value C (in mg/mm2) as:

C C1 + C2 + C3
=
3

Record the mean value to one decimal place.