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Technical Data Sheet
Ancaster Limestone - Weatherbed Buff
Rare Stone Group
Wilsford Glebe Quarry, Ancaster, Lincs
Contact : The Rare Stone Group
Tel. 01623 623 092 Fax. 01623 622 509

email:
enquires@rarestonegroup.co.uk
website :
www.rarestonegroup.co.uk
Grid Reference: SK 991 407

Compiled March 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 September 1999 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 Rare Stone Group and does not represent an endorsement of the stone by BRE.

General
The quarry is south of the village of Ancaster off the B6403 on the road to Wilsford and Barkston Heath Airfield (GR SK 991 407). The stone was worked by both the Romans and the Saxons. The present quarry, which is surrounded by old working, has been worked since around 1957. There are reserves of over 100,000 tonnes.

Petrography 

Ancaster Stone is an oolitic limestone from the Lincolnshire Limestone formation of middle Jurassic age. Traditionally, three beds of stone have been worked from beneath around 8m of overburden - the Weatherbed, Hard White and Freestone. The Freestone was not included in the current project.

The Weatherbed is a warm-brown coloured shelly stone. The depth of this bed is around 2.2m with individual quarry blocks around 2000mm x 1000mm x 850mm on bed. The stone from the bottom of the bed can be very shelly and takes an excellent polish.

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 Ancaster has been used for many years in a wide range of locations but there always seems to have been a careful selection of stone from different beds for individual projects.

The porosity indicates a quite dense stone that will have good resistance to weathering. The sodium sulphate crystallisation result also indicates that the stone will have very good resistance to salt damage and that it will perform well in all but the most exposed locations where it may it may require some extra protection or careful design and detailing to shed water. The strength is towards the upper end of the range for limestones and so the performance should be good.

Test Results - Ancaster limstone-Weatherbed (Buff)
Safety in Use 
Slip Resistance (Note 1) 
63 
Values > 40 are considered safe. Note: Polished surfaces are usually around 15-20 when wet.
Abrasion Resistance(Note 1) 

N.D.

Values <23.0 are considered suitable for use in heavily trafficked areas 
Strength under load 
1) Compression(Note 2) 

N.D.
MPa

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

N.D.
MPa

Loaded parallel to the bedding plane ambient humidity
Porosity and Water Absorption 
1) Porosity (Note 3) 
10.8% 
2) Saturation Coefficient (Note 3) 

0.81

3) Water Absorption

3.6% (by wt)

4) Bulk specific gravity 
2411kg/m3 
Resistance to Frost 
Freeze/Thaw Test (Note 1) 

N.D. 

Resistance to Salt 
Sodium Sulphate Crystallisation Test (Note 3) 
-0.85% Mean wt loss 

(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 1997. N.D. = not determined

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