This data sheet was compiled by the Building Research Establishment (BRE). The data sheet was compiled in November 1997 and updated in June 2000 using BRE test results and data collected in earlier surveys. The work was carried out by BRE as part of a Partners in Technology Programme funded by the Department of the Environment, Transport and the Regions and Blockstone Ltd and does not represent an endorsement of the stone by BRE.

General
The quarry is near the town of Whatstandwell in Derbyshire. The quarry has been producing stone since the early part of the 19th century and it has been used in buildings since at least 1825

Petrography 
Dukes Gritstone is a Millstone Grit of Carboniferous age. It is a medium-grained stone, pink/lilac in colour with iron, black and buff markings. The average block size is 1400mm x 900mm 700mm.

Expected Durability and Performance 
It is important that the results from the 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. Carboniferous Sandstones are traditionally acknowledged as generally being a very durable building and paving stone and have been used extensively in many towns and cities in the UK. Dukes Gritstone appears to be a durable stone that is not effected by acid rain or air pollution and like most sandstones it is expected have good frost resistance. The compressive strength of the stone is typical of the range for sandstones and is comparable with the stronger UK limestones.

Overall, Dukes Gritstone should be suitable for use in most aspects of load bearing masonry and cladding.

Test Results - Dukes Gritstone

Safety in Use
Slip Resistance (Note 1)	Not determined	Values > 40 are considered safe.
Abrasion Resistance (Note 1)	Not determined	Values <23.0 are considered suitable for use in heavily trafficked areas
Strength under load
1) Compression(Note 2)	74.9 MPa	Loaded perpendicular to the bedding plane ambient humidity
1) Compression(Note 5)	39 - 50 MPa	Dry. Loaded perpendicular to the bedding
2) Bending (Note 1)	8.7 MPa	Loaded perpendicular to the bedding plane ambient humidity
	4.8 MPa	Loaded parallel to the bedding plane ambient humidity
Porosity and Water Absorption
1) Porosity (Note 3)	14.11%
2) Saturation Coefficient (Note 3)	0.67
3) Water Absorption	4.18 % (by wt)
4) Bulk specific gravity	2269kg/m3
Resistance to Frost
Freeze/Thaw Test (Note 1)	Not determined
Resistance to Salt
Sodium Sulphate Crystallisation Test (Note 3)	3.13% Mean wt loss
Resistance to Acidity
Acid Immersion Test(Note 4)	Pass	All samples passed the test with no splitting or delamination

(Test methods Note 1 = prEn1341, Note 2 = prEn 1342, Note 3 = prEn 1341 /BRE 141, Note 4 = BRE 141, Note 5 = ASTM)

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