Testing for issues with pyrite & mica.
THE PROBLEM
Soils / Rocks / Aggregates and some older building products (Bricks & Blocks) that contain pyritic or micaceous material i.e., gypsum can be very troublesome and cause issues such as cracking of slabs, heave and reduced performance.
These issues arise when materials that contain pyrites, mica or gypsum react with moisture and air.
The reaction causes oxidisation of the minerals and a byproduct of this reaction is sulphuric acid (H2SO4). This acid then attacks the soil, rock or blockwork causing it to swell. This “heave” effect will then potentially generate cracking of the structures built upon the affected ground
IDENTIFICATION
Ground investigation work will generally involve taking samples for laboratory analysis to identify the presence of soils and rocks that have elevated sulphate and sulphur levels prior to construction. This is usually done in the form of chemical analysis that will give the levels of soluble sulphates and sulphur compounds. This will aid designers when planning building works so they can reduce the risk of the acid attack and subsequent heave.
At TTL we can offer a number of laboratory techniques that will not only identify but also quantify the presence of pyritic, micaceous and gypsum as well as the physical characteristics that will affect the performance of construction materials.
These methods can be undertaken on the Soils, Rocks or aggregates and building materials within our laboratories by experienced practitioners.
These Methods include:
• Analytical chemistry techniques
• Mineralogical analysis by XRD (X-Ray Diffraction)
• Thin section petrographic analysis
• A suite of physical testing to certify the suitability of quarried materials including;
• Particle size
• Water absorption
• Moisture content
• LA abrasion
• Micro Deval
• Soundness
• Plasticity index
Need advice and testing of suspect materials?
Let our experts help find a solution!
CONTACT US
To discuss your individual requirements, please contact our experienced and dedicated team who can advise you of the survey you require.
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