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Petrography | Durability |
Test Results
Technical Data Sheet
Elm Park Limestone
Wessex Dimensional Stone Ltd
Teffont Quarry, Chilmark
Salisbury, Wiltshire, SP3 5BP
T 01722 716815 F 01722 716818 E info@wessexdlstone.com
Grid
reference :
Compiled January 2000
This data sheet was compiled by the Building Research Establishment (BRE). Where possible, data
collected in earlier surveys has been used to help interpret the test results. The data sheet was compiled in
January 2000 using the results of tests carried out to the proposed European Standards. 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 the Elm Park Mine and does not represent an endorsement of
the stone by BRE.
General
The mine is located near to Garstad in Wiltshire. There are plenty of reserves of stone.
Petrography
Elm Park Stone is an oolitic limestone from the Great Oolite of middle Jurassic age. The stone is mined and
is buff in colour
Expected Durability
and Performance ;
It is important that the results from the sodium sulphate crystallisation tests are not viewed in isolation. They
should be considered with the results from the porosity and water absorption tests and the performance of
the stone in existing buildings. Stone from this area is traditionally acknowledged as being less durable than
stones such as Portland Whit Bed but it has been used extensively where a faster rate of weathering is
acceptable or where its working qualities were required. The crystallisation test results show the stone to be
Class D which BRE Report 141 suggests that it is suitable for plain walling and cladding. The results from
the other tests suggest that the soundest stone may well perform better than these classes in the current
environment. When using Elm Park Stone it is especially important that the detailing of the stonework is
designed to offer the maximum protection to rainwater and rainwater runoff. Based on current research it
seems likely that the stone would weather at a rate of between 3 and 4 mm per 100 years but it could be
greater in severe exposures or on the edges of stonework. The strength is towards the lower end of the
range for limestones but the performance should satisfactory if the relevant British Standards are followed.
The abrasion resistance is moderate and so the stone should not be used in heavily trafficked areas.
Test Results
- Elm Park Limestone
| Safety
in Use |
| Slip Resistance
(Note 1) |
n.d.
|
Values
> 40 are considered safe |
Abrasion Resistance(Note
1) |
27.1
|
Values <23.0 are considered suitable for
use in heavily trafficked areas |
| Strength
under load |
| 1) Compression(Note
2) |
28.3 MPa
|
Loaded perpendicular to the bedding plane- ambient
humidity |
| 2) Bending (Note
1) |
4.7 MPa
|
Loaded perpendicular to the bedding plane- ambient
humidity |
| |
4.3 MPa
|
Loaded parallel to the bedding plane- ambient humidity |
| Porosity
and Water Absorption |
| 1) Porosity (Note
3) |
17.3%
|
|
| 2) Saturation Coefficient (Note
3) |
0.80
|
|
| 3) Water Absorption |
6.2% (by wt)
|
|
| 4) Bulk specific gravity |
2245
kg/m33
|
|
| Resistance to Frost |
Freeze/Thaw Test
(Note 1) |
n.d.
|
| Resistance to Salt |
| Sodium Sulphate Crystallisation Test (Note
3) |
23.7% Mean wt loss
|
|
(Test methods Note 1 = EN1341, Note 2 = EN 1342, Note 3 = EN 1341 /BRE 141, Note 4 = BRE 141)
Tests were carried out at BRE in 1997. n.d. = not determined
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