Fancy Beach Whitbed

Fancy Beach Whitbed is the geological name for the bed of stone in Fancy Beach Quarry Quarry that encompasses Jordans Whitbed and Fancy Beach Whitbed. This technical data sheet is based on a format compiled by the Building Research Establishment (BRE) at the request of Albion Stone. The 102 tests have been carried out in accordance with current European standards by the BRE on Albion Stone's behalf, or by other accredited testing houses. The work carried out by the BRE on this technical data sheet has been undertaken as a paid commission and does not represent an endorsement of the stone by the BRE.

A. Petrography

Macro Examination (BRE Reference 231039/06/02/117)
The stone was off-white in colour and had a medium–to coarse–grained texture. It effervesced with 10% hydrochloric acid indicating that it contained calcite. The clasts ranged in size from <0.5 to 9mm. There was a moderate abundance of bioclasts present, such as mollusc shell fragments. There was some preferred alignment of elongate clasts, possibly denoting sedimentary bedding. The stone had a pitted appearance which may indicate the presence of open voidage.

Microscopical Examination (BRE Reference 231039/06/02/117)
The limestone was moderately compacted, and clast supported. The clast matrix ratio was visually estimated at 95:5. There was possibly some evidence of sedimentary bedding by the preferred alignment of elongate clasts.

Clasts
There were ooliths, which were visually estimated to account for 80% of the total stone. Then ooliths were spherical in shape and ranged in size from 150 to 600µm, mean 400µm. The ooliths were composed of micritic carbonate often with a poorly preserved internal structure. They were seeded by sparitic and micritic carbonate, and angular quartz (1 to 2%).

Elongate mollusc shell fragments (bivalves) were visually estimated to account for 15% of the stone. The mollusc shell fragments ranged in size from 250µm to 7mm and were composed of sparitic carbonate often with a well preserved internal structure. These showed some preferred orientation possibly denoting sedimentary bedding. There was also occasional echinoderm fragments observed.

Quartz was visually estimated to account for 1 to 2% of the stone. It was angular in shape and up to 250µm in size.

Matrix
The matrix was visually estimated to account for 5% of the stone. The matrix was predominantly composed of euhedral shaped sparitic syntaxial carbonate crystals which were up to 1mm in size. Micritic carbonate was also observed.

Viodage
There was a moderate to high abundance of open interparticle voidage space observed. The voids were visually estimated to account for 10 to v15% of the stone and they ranged in size from 40 to 750µm. The micritic carbonate present had a moderate capillary porosity.

Composition
The micritic and sparitic carbonate which made up the clastic and matrix components were composed of non-ferroan calcite. There was also 1 to 2% quartz present.

Classification
Based on the description given here, this stone would be classified as a moderately sorted, moderately compacted, clast supported Oosparite Limestone.

Results Summary
The stone was classified as a moderately sorted, moderately compacted, clast supported Oosparite Limestone. The clasts were predominantly composed of ooliths, but mollusc shell and echinoderm fragments and quartz were also present. The matrix was composed of sparitic syntaxial carbonate and some micritic carbonate. There was a moderate to high abundance of open voidage space. There was possibly some evidence of sedimentary bedding by the preferred alignment of elongate clasts.

B. Strength

1. Compression - BS EN 1926
Average: 47.04 Mpa from 26 tests
Lowest Expected Value 35.53 Mpa
Highest Expected Value 61.06 Mpa

2. Flexural Strength - BS EN 13161
Average: 5.82 Mpa from 52 tests
Lowest Expected Value 3.61 Mpa
Highest Expected Value 8.93 Mpa

3. Breaking Load at Dowel Hole - BS EN 13364
Average: 4,667 N from 20 tests
Lowest Expected Value 3,749 N
Highest Expected Value 5,668 N

C. Durability

1. Water Absorbtion - BS EN 13755
Average: 6.45% from 6 tests
Lowest Expected Value 5.48%
Highest Expected Value 7.56%

2. Density - BS EN 1936
Average: 2,115 kg/m³ from 18 tests
Lowest Expected Value 2,066 kg/m³
Highest Expected Value 2,166 kg/m³

3. Porosity - BS EN 1936
Average: 21.57% from 22 tests
Lowest Expected Value 19.55%
Highest Expected Value 23.73%

4. Saturation Coefficient - BS EN 1936
Average: 0.64 from 10 tests
Lowest Expected Value 0.61
Highest Expected Value 0.66

Technical Summary

Prepared by:Dr T Yates, BRE (Building Research Establishment) Durability and Weathering
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 the Portland Whitbed is traditionally acknowledged as generally being a very durable building stone and it has been used extensively in many towns and cities in the UK . Comparing the results for the Whitbed Stone from Jordans Quarry to those collected from buildings, exposure trials and tests on quarry samples collected by BRE during the last 70 years shows that this stone compares very well with the traditional view of Portland Whitbed. Previous research at BRE has shown that Portland limestone which has a low saturation coefficient (<0.72), a low microporosity (<11.0 of the stone by volume) and an open oolitic structure generally performs well over long periods when used on buildings. The results summarised on these sheets show that the limited number of samples tested meet these criteria. The average crystallisation test results show the stone to be Class C which BRE Report 141 suggests is suitable for most uses including where exposure conditions are to be more severe, for example high concentrations of sulphur dioxide or severe frosts, or where a long life is required (for example >50 years). In all cases it is important that the detailing of the stonework is designed to offer the maximum protection from rainwater and rainwater runoff.

Based on current research it seems likely that the stone would weather at a rate of between 1 and 2 mm per 100 years but it could be greater in severe exposures.

(Weathering rates are based on the BRE interpretation of historical data dating from 1932)

Revision 2 DECEMBER 2007