Shrinkage Testing: Predict Clay Movement Before It Becomes a Problem
Shrinkage testing measures how much a soil sample reduces in volume as it dries. It’s particularly important for fine-grained soils such as clays, where moisture loss can lead to significant shrinkage and, in turn, cracking, settlement, or movement beneath structures.
The test typically involves preparing soil at (or close to) its liquid limit, placing it into a mould/trough, and allowing it to dry in stages—first by air drying, then heat-assisted drying, and finally drying in an oven. The reported result is commonly expressed as the percentage reduction (shrinkage) as the sample dries.
Why shrinkage testing matters
Engineers use shrinkage results to assess:
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suitability of soils beneath foundations, roads, and embankments
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the likelihood of seasonal movement during moisture loss (e.g., summer or drought conditions)
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risk of shrink–swell behaviour that can affect long-term stability and serviceability
Shrinkage testing can be carried out as a standalone test or combined with Atterberg Limits to build a clearer picture of soil plasticity and moisture sensitivity.
Why choose The Testing Lab PLC?
At The Testing Lab PLC, we provide shrinkage testing with careful sample preparation, consistent methods, and clear reporting—so your team can make confident decisions about design risk and material suitability.
Need shrinkage testing? Contact The Testing Lab PLC to discuss your samples and turnaround.

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