Avoiding failures in dimension stone
Testing of dimension stone is also vital in avoiding product failures. Stone is a natural product, so understanding its strengths, weaknesses and any variability is important. If you’re testing for a particular project, it’s best to test from a batch proposed for use on the project. It’s also important for us to test at a thickness and finish that is relevant to the project.
Which tests are right for your stone?
Stone Initiatives is the only NATA-accredited laboratory in Australia that is dedicated to dimension stone testing and evaluation. You can send stone samples to be tested at our lab here in Adelaide, and we also work on dimension stone projects on site in Adelaide, Sydney, Melbourne, Brisbane, around Australia and internationally. Test programs can be compiled from a wide range of tests conforming to ASTM, European and Australian standard procedures. Quality assurance testing by statistical sampling can be carried out to assist in the continuous production of a quality product at the quarry and factory level. Get in touch to discuss which tests are right for your product or project.
Water Absorption – ASTM C97/C97M
This test determines the water absorption characteristics of dimension stone. Specimens are first oven dried to a constant mass, then immersed in water under atmospheric pressure. The mass gain is expressed as % absorption by weight, and % absorption by volume (indicative of porosity). These results help assess a stone’s susceptibility to moisture ingress, which can affect durability, contribute to staining, and influence its suitability for specific applications.
Bulk Specific Gravity – ASTM C97/C97M
Bulk specific gravity measures the density of the stone by comparing its mass to an equivalent volume of water. When interpreted alongside water absorption results from the same test method, it can provide insight into the stone’s density and overall durability. In general, stones with higher bulk specific gravity tend to have lower porosity and lower water absorption, characteristics typically associated with improved durability and performance in service. The bulk specific gravity result also gives a convenient and accurate method of calculating the unit weight of stone panels and pavers.
Compressive Strength – C170M
The compressive strength test evaluates a dimension stone’s capacity to withstand compressive loads before failure. A prepared stone specimen is subjected to increasing pressure at a pre-determined load rate, until failure, establishing the maximum load the material can support. The results are used to assess the stone’s structural capacity and suitability for load-bearing applications such as flooring, paving or structural stonework.
Flexural Strength – C880M
The flexural strength test measures the ability of a dimension stone to resist flexural forces. A stone specimen is supported either end and two bar (quarter-point) loaded until failure, determining the maximum load (Newtons) and Flexural Strength (MPa) of the material. This test provides an indication of the stone’s performance in applications where it may be exposed to flexural forces, such as cladding, panels, or benchtops.
Modulus of Rupture – C99M
The modulus of rupture test determines the breaking strength of a dimension stone. A stone specimen is supported either end and single bar (mid-point) loaded until failure, determining the breaking load (Newtons) and Modulus of Rupture (MPa) of the material. It provides an indication of the stone’s ability to resist tensile stresses caused by bending, which may be important for flooring, paving or tiles. The results can be used to calculate theoretical breaking loads for various sizes and formats.
Resistance to Salt Attack – AS/NZS 5546.10 (Method A)
Resistance to Salt Attack evaluates the durability of dimension stone material when exposed to repeated cycles of soaking in a salt solution and overnight drying, promoting salt crystallisation. It is a quantitative and qualitative test that determines weight loss and is also useful for determining the likely deterioration of surfaces in environments where salt exposure may occur, such as coastal environments, wet areas or other areas regularly exposed to wet cleaning techniques.
Abrasion Resistance – ASTM C1353
Abrasion resistance is the measure of a dimension stone’s ability to withstand surface wear caused by foot traffic or other mechanical actions. This test method is used for determining the index of abrasion resistance by measuring the loss of mass resulting from abrasion. It helps assess how well the material will maintain its appearance and performance when used in flooring or other high-traffic applications.
Other Dimension Stone Tests
Dimensional Stability – SI-DIM
Coefficient of Thermal Expansion – SI-LTE
Freeze Thaw Resistance – ISO 10545-12
Resistance to Acid Attack – SI-AC
“Natural stone is highly variable, formed through complex geological processes. Its properties can differ between quarries and even within the same quarry, leading to variations in appearance and performance from block to block. Solely relying on outdated, incomplete, or supplier-provided test data can be risky. The most reliable approach is testing material that reflects current quarry production at a NATA accredited facility. At Stone Initiatives, we provide comprehensive dimension stone testing, whether you need one-off project-specific assessments or ongoing quality assurance testing to monitor consistency over time.”
Mark Milevski
Co-Director, Materials Testing Specialist, Heritage Services Specialist
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Frequently asked questions
Is there a standard I can benchmark my stone test results against?
It ultimately depends on the test method, however, ASTM International has authored standard specifications for the main stone types: granite, marble, limestone, sandstone and travertine. These standard specifications provide benchmark physical property test values that are characteristic of stone that has been used successfully for general structural and building purposes. Generally, the test results covered in these specifications are water absorption capacity, density, abrasion resistance, compressive strength, modulus of rupture strength and/or flexural strength.
I am opening a new quarry site. What are the basic physical property tests I can have performed on my stone?
The basic suite of physical property tests that can be carried out on dimension stone include water absorption capacity/bulk specific gravity, flexural strength, modulus of rupture strength, compressive strength, abrasion resistance, and durability/resistance to salt attack. On a tight budget, a water absorption test and modulus of rupture strength is a good starting point for determining the basic physical properties of a stone type. See more on our Summary of Capabilities page.
Can you determine the composition and classification of my stone?
We can perform a detailed petrographic analysis with a polarising light microscope that will determine the stone’s mineral composition, textural features, geological name, commercial stone industry name, presence of deleterious minerals or asbestos, and most importantly will identify any other features of potential concern revealed in the analysis.
We can also facilitate X-ray diffraction analysis, which is a more basic compositional test that determines the crystalline components (minerals) present within the stone and highlights any potential asbestiform minerals.
My externally installed bluestone tiles are coming unstuck from the substrate and breaking, what is happening?
Large-format, thin bluestone tiles are known to be quite dimensionally sensitive. This may be due to moisture sensitivity or temperature-driven expansion or a combination of the two. We can perform a variety of dimensional stability tests prior to installation to help determine ideal adhesive selection and joint spacing to avoid such issues. Where a failure has already occurred, we can perform the same dimensional stability tests as part of an investigation to help determine the cause of failure.
How much stone is required for basic physical property testing?
Generally, for a basic suite of physical property tests, the standard sample requirement is 10 pieces 100 x 200 x 60mm for modulus of rupture strength, 10 pieces 100 x 350 x 30mm for flexural strength, and three pieces 300 x 300 x 50 for water absorption/bulk specific gravity, compressive strength, abrasion resistance and durability/resistance to salt attack. The sample requirements will differ if more or fewer tests are requested. When we provide a quote for a particular testing program, the sample requirement will be included. The sample quantity can also be modified if there is limited material available, however, this will typically be noted on the test result certificate.