Introduction
Full project details
Stone list
BRE Home Page
British Stone Home Page
|
Petrography | Durability | Test Results
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
: enquiries@dunhouse.co.uk 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 = prEn1341, Note 2 = prEn 1342, Note 3 = prEn 1341 /BRE
141, Note 4 = BRE 141)
Tests were carried out at BRE in 2000
Back to top of page | Back to stone list
|