Petrography | Durability | Test Results
Technical Data Sheet
Salterwath Limestone
Pickering Quarry, Crosby Ravensworth near Penrith
Compiled September 1997
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 September 1997 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
and Cumbria Stone Quarries Ltd and does not represent an endorsement of
the stone by BRE.
General
The quarry is about 3 miles north-west of Orton off the
B6261. There are old quarries nearby and also areas for future expansion.
Petrography
Salterwath Stone is fine grained limestone of early Carboniferous
age. Dark blue when newly quarried, it weathers to a plae grey when used
externally. It is dense and easily takes a polish which gives a rich choclate
brown shade. There are six beds of stone under approximately 3.5m of overburden
in a long working face. Blocks over 2m long can be obtained with the average
depth of stone on bed around 350mm.
Expected Durability
and Performance
It is important that the results from the 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. Dense Carboniferous limestones 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. Salterwath limestone
appears to be a durable stone that will have good resistance to acid rain
or air pollution. In addition, the low weight lost in the sodium sulphate
crystallisation test indicates good resistance to salt damage (for example
in coastal locations or from de-icing salts); the stone should also have
good frost resistance. The compressive strength of the stone is high for
a limestone and is comparable with many sandstones. The high density and
compressive strength indicate that the stone should be suitable for use
in heavily trafficked areas.
Overall, should be suitable for use in most
aspects of construction including flooring, paving, load bearing masonry
and cladding including areas where a long service life is needed.
Test Results-
Salterwath Limestone
| 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) |
102 MPa
|
Conditions of testing not known |
| 2) Bending (Note 1) |
Not Determined
|
Loaded perpendicular to the bedding - ambient
humidity |
| Porosity
and Water Absorption |
| 1) Porosity (Note 3) |
0.4 - 4.7%
|
|
| 2) Saturation Coefficient (Note 3) |
0.85 - 1.00
|
|
| 3) Water Absorption |
0.2% (by wt)
|
|
| 4) Bulk specific gravity |
2687 kg/m3
|
|
| Resistance to Frost |
| Freeze/Thaw Test (Note 1) |
Not Determined
|
|
| Resistance to Salt |
| Sodium Sulphate Crystallisation Test
(Note 14 |
Mean: 0%
|
|