Copp Cragg Specification

General
The Quarry is at Byrness. It is part of the Lower Carboniferous group of sandstones. The bed height is greater than 2m and maximum block size is 2 x 2.5 x1.5 m with a maximum supplied size of 1.5 x 2 x 1.5 m. There are suitable reserves and material can be supplied in a variety of formats.

Petrography 
Copp-Cragg is a yellow-brown fine grained, non-calcareous sandstone.

Expected Durability and Performance 
It is important that the results from individual tests are not viewed in isolation. They should be considered together and compared to the performance of the stone in existing buildings and other uses. Sandstone is traditionally acknowledged as generally being a very durable building and paving stone and has been used extensively in many towns and cities in the UK. Copp-Cragg sandstone appears to be a durable stone that will have moderate resistance to acid rain or air pollution. In addition, the slight weight lost in the sodium sulphate crystallisation test indicates moderate resistance to salt damage special consideration may be required for locations with harsher environments (for example in coastal locations or from de-icing salts). From the frost test the stone should also have good frost resistance. The compressive and flexural strength of the stone is in the lower end of the range for sandstones. The density and compressive and flexural strength indicate that the stone should be suitable for use in medium trafficked areas.

Overall, Copp-Cragg should be suitable for use in general use in all aspects of construction including flooring, paving, load bearing masonry and cladding. Special consideration should be taken in uses with a very severe environment or where a long service life is needed.

Test Results – Copp Cragg

Safety in Use
Slip Resistance (Note 1)

84

Wet Values > 40 are considered safe.
Abrasion Resistance (Note 1)

Not Tested

Values <23.0 are considered suitable for use in heavily trafficked areas
Strength under load
1) Compression(Note 2)

89.4 MPa

Loaded perpendicular to the bedding plane ambient humidity
2) Bending (Note 1)

4.1 MPa

Loaded perpendicular to the bedding plane ambient humidity

Not Tested

Loaded perpendicular to the bedding plane ambient humidity
Porosity and Water Absorption
1) Porosity (Note 3)

17.8%

2) Saturation Coefficient (Note 3)

0.57

3) Water Absorption

4.6 % (by wt)

4) Bulk specific gravity

2186kg/m3

Resistance to Frost 
Flexural strength after Freeze/Thaw Test (Note 1)

3.6 MPa

Loaded perpendicular to the bedding plane ambient humidity
Resistance to Salt
Sodium Sulphate Crystallisation Test (Note 3)

-0.99% Mean wt loss

Resistance to Acidity
Acid Immersion Test(Note 4)

Pass

(Test methods Note 1 = EN1341, Note 2 = EN 1342, Note 3 = EN 1341 /BRE 141, Note 4 = BRE 141)