The Irish Blue Limestone is a natural material and the physical properites reflect the conditions under which the stone originally formed and the subsequent geological history of Ireland. The best guarantee for the stone is its successful use as a building material in Ireland during the last 3000 years and the fact that many of the older structures built with it are still standing.
Today engineers and architects normally seeks to confirm the suitability of the stone by using a range of tests to quantify what are considered to be the important physical parameters of the material. Unfortunately, because the material is not synthetic, random variation is inevitable both within a single bed and between different levels within a single quarry.
The Irish Blue Limestone from the Threecastles Quarry , Co Kilkenny has been tested by a wide range of laboratories in a number of countries during the last 15 years and the test results below are from January 2005 . Over the years there is little variation in the periodic test results taken .
Where certain properties of the stone are of paramount importance to a particular project, the various International Standards all recommend that accurate sampling and testing of the material to be used should be undertaken. In accordance with these principles, Mc Keon Stone Ltd will always facilitate the collection of representative samples which prospective customers may wish to test prior to use in major projects.
| Test | Units | Minimum | Typical | Maximum |
| Apparent Density | Kg/m3 | 2671 | 2680 | 2700 |
| Porosity | % Vol. | 0.43 | 0.48 | 0.54 |
| Frost Resistance | No Effect | |||
| Capilliarity Coefficient | GC | -5.55 | -6.8 | -8.43 |
| Thermal Expansion Coefficent | Mm/m.K | 0.0051 | 0.0055 | 0.0058 |
| Thermal Conductivity | W/Mk | 2.5 to 3.1 | ||
| Compressive Strength | N/mm2 | 120 | 136 | 151 |
| Flexural Strength | N/mm2 | 14.2 | 16.8 | 19.8 |
| Ultrasonic Velocity | m/s | 5180 | 5416 | 5785 |
| Scratch Test | Mm | 0.3 | ||
| Abrasion Resistance | Mm | 18.1 | 18.5 | 19.4 |
| Modulus of Elasticity | kN/mm2 | 74.85 | 75.24 | 75.97 |
| Water Absorption | % Dry Mass | 0.12 | 0.14 | 0.20 |
| Sulphate Attack, SO2 | Insensitive due to compact grain structure and extremely low iron composites content. No risk of brown discoloration and staining | |||
| Sound Insulation | Dependent on homogenous mass, large blocks of Irish Blue Limestone off good sound attenuation. | |||
The standards used for the various tests are as follows:
| Apparent Density | NBN EN 1936: 1999 |
| Porosity | NBN EN 1936: 1999 |
| Frost Resistance | NBN EN 12371 : 2002 |
| Capillarity Coefficient | NBN B05-201 |
| Thermal Expansion Coefficient | Pr EN 14581: 2004 |
| Compressive Strength | NBN EN 1926 : 1999 |
| Flexural Strength | NBN EN 12372 :1999 |
| Ultrasonic Velocity | NBN B15-229 |
| Abrasion Resistance | EN 14157: 2004 |
| Modulus of Elasticity | PR EN14146 : 2003 |
| Water Absorption | NBN B15-221, ASTM C97-83, BS EN 13755 |
The test protocols used to determine the physical properties have been given. If the values are to be used for design calculations it is important to confirm that the test cited is comparable with the relevant country standard.
Slip Resistance
Slip resistance tests were carried out using two slip measurement techniques, TRL and 4S and the results are shown below in Dry and Wet conditions. An Explanation of the values is shown in the tables below.
| Finish | Dry TRL |
Wet TRL |
Dry 4S |
Wet 4S |
| Sanded (C24) | 68 | 51 | 70 | 60 |
| Blue Honed 320 grit | 59 | 19 | 50 | 30 |
| Dark Honed 400 grit | 54 | 10 | ||
| Bushammered | 77 | 78 | ||
| Flamed | 82 | 79 |
| Safety Category | Dangerous | Marginal | Satisfactory | Excellent |
| TRL pendulum value | <19 | 20 – 39 | 40 – 74 | > 75 |
| Potential for Slip | High | Moderate | Low | Extremely Low |
| 4S pendulum value | <25 | 25 – 35 | 35 – 65 | > 65 |