Bearl Sandstone

Technical Data Sheet
Bearl Sandstone
Bearl Quarry
Dunhouse Quarry Works, Staindrop Darlington,
County Durham DL2 3QU,England
Contact : Dunhouse Quarry Ltd
Tel. +44 (0) 1833 660 208; +44 (0) 1833 660 749
FAX +44 (0) 1833 660 748
Email : [email protected]
Web site : http://www.dunhouse.co.uk
Grid reference : —- —-
Compiled May 2000

This data sheet was compiled by the Building Research Establishment (BRE). It is based on collated BRE data and from current tests at BRE (2000). The data sheet was compiled in May 2000. The work was carried out by BRE as part of a Partners in Technology Programme funded by the Department of the Environment and Dunhouse Quarry Co. Ltd and does not represent an endorsement of the stone by BRE.

General
Bearl Quarry is near Stocksfield, Northumberland and is operated by Dunhouse Quarry Co. Ltd.. There is a maximum bed height of 3m and block sizes of 2 x 2 x 2 m can be achieved. The material is not suitable for veneers. The quarry is operated when required and reserves are good. The quarry was not worked for a few years but work commenced in 1988.

Petrography
Buff to white fine to medium grained slightly micaceous non-calcareous sandstone.

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. 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. Bearl sandstone appears to be a less durable stone but it should still have good resistance to acid rain and air pollution. The high weight loss in the sodium sulphate crystallisation test indicates low resistance to salt damage (for example in coastal locations or from de-icing salts). From the frost test the stone should have reasonable frost resistance. The compressive and flexural strength of the stone is low for a sandstone in comparison with other sandstones. The flexural and compressive strength indicate that the stone should be suitable for use in moderately trafficked areas. It may be necessary to consider slightly thicker paving slabs where the stone is likely to be poorly supported by the sub-base.

Overall, Bearl should be suitable for use in most aspects of construction including flooring and load bearing masonry if due caution is taken regarding the low strength. Special consideration will be required where there is the prospect of extreme exposure and where a long service life is needed. At present, the material is not used for veneers, paving and setts.

Test Results – Bearl Sandstone

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)

59.2 MPa

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

5.3 MPa

Loaded perpendicular to the
bedding plane
ambient humidity

Not Tested

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

14.9%

2) Saturation Coefficient (Note 3)

0.65

3) Water Absorption

4.3 % (by wt)

4) Bulk specific gravity

2246kg/m3

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

4.7 MPa

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

4.21% 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, Note 5 = Based on earlier BRE data)

Tests were carried out at BRE in 2000. N.D. = not determined

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