Physical Properties

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
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