Petrography | Durability | Test Results
Technical Data Sheet
Plumpton Red Lazonby Sandstone
Lazonby Fell Quarry, near Penrith
Compiled July 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 July 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 situated at the end of a long track in
the woods off the B6413 between Plumpton and Lazonby. The area is full
of old quarries which were worked from the early 19th century. There appear
to be virtually limitless reserves of stone as long as planning permission
continues to be obtained. The current quarry has been worked since 1980.
There are three or four beds of stone upto 750mm deep providing stone of
600mm on bed. Long, wide blocks are available. The depth of the face is
about 5.4m although there is thought to be stone below the present level
of the quarry face giving a total depth of 30m of stone.
Petrography
1. Macroscopic
Plumpton Red Lazonby is from the New Red Sandstone of
Permian age. It is a fine- to medium grained stone, pale red or dark pink
in colour and it has a sparkle due to the presence of quartz grains. A
pale pink stone and a white stone are also available but these are only
used locally.
2. Microscopic
Mature sub-arkose, moderately well sorted with a porosity
~10-15%
The thin section is dominated by fine to medium grained
quartz grains which have a bi-modal distribution; 1.0 -0.5 and 0.25-0.025.
All the grains are coated with a thin layer of iron oxide which accumulated
during deposition. Around the original grain there is a quartz overgrowth
which are in optical continuity. Where the quartz over-growths occurs in
a pore it has a flat surface as though there was something there; which
has since been lost. It The quartz grains and overgrowths account for 75-85%
of the mineralogy. In addition to quartz there are a few granitic or gneissose
grains, feldspar, corundum and mica grains together with opaques (haematite
and magnetite).
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. Sandstones from the New Red Sandstone series 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. Plumpton Red Lazonby
sandstone appears to be a durable stone that is not effected by acid rain
or air pollution. In addition, the low weight lost in the harsh saturated
sodium sulphate crystallisation test indicates good resistance to salt
damage (for example in coastal locations or from de-icing salts); the stone
seems to have good frost resistance. The compressive strength of the stone
is typical of the range for comparable with sandstone. The flexural strength
is towards the lower end of the range for sandstones and if used for paving
then the units may need to be thicker than those for some other sandstones.
The abrasion resistance is comparable with York paving stones and 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 or where
high salt concentrations are expected.
Test Results
| Safety
in Use |
| Slip Resistance (Note 1) |
Wet: 76
|
Values > 40 are considered safe |
| Abrasion Resistance(Note 1) |
19.6
|
Values <23.0 are considered suitable for
use in heavily trafficked areas |
| Strength
under load |
| 1) Compression(Note 2) |
118 Mpa
|
Loaded perpendicular to the bedding - ambient
humidity |
| 2) Bending (Note 1) |
5.9 Mpa
|
Loaded perpendicular to the bedding - ambient
humidity |
| Porosity
and Water Absorption |
| 1) Porosity (Note 3) |
10.3%
|
|
| 2) Saturation Coefficient (Note 3) |
0.51
|
|
| 3) Water Absorption |
2.2% (by wt)
|
|
| 4) Bulk specific gravity |
2376 kg/m3
|
|
| Resistance to Frost |
| Freeze/Thaw Test (Note 1) |
The samples showed no evidence of damage after 120
test cycles
|
|
| Resistance to Acidity |
| Acid Immersion Test (Note 4) |
Pass
|
All samples passed the test with no splitting
or delamination |
| Resistance to Salt |
| Sodium Sulphate weight Crystallisation Test
(Note 14) (saturated test) |
Mean: 5.1%
|
(Note: earlier tests give values around 25%
(wt loss) loss and this is probably more typical of the stone) |