Amtest offers full laboratory testing of fine-grained soils to determine their plastic limit, in accordance with BS EN ISO 17892-12:2018+A2:2022. We provide accurate results for project planning, quality control, and soil classification.
While Plastic Limit tests are usually performed in the lab for precision, Amtest can advise on sample collection and logistics from your site to ensure testing reflects actual ground conditions.
Yes. Amtest delivers a clear, professional report showing the test procedure, measured plastic limit, and recommendations, which can be used for compliance, design, or quality assurance purposes.
Yes we are. Please see our UKAS Schedule of Tests.
The Plastic Limit test (BS EN ISO 17892-12:2018+A2:2022) determines the water content at which fine-grained soil changes from a semi-solid to a plastic state. This essential geotechnical test provides a key indicator of soil consistency and workability, helping engineers assess the behaviour of clays and silts under load or during construction.
During the test, a prepared soil sample is rolled into threads until they begin to crumble at a diameter of 3 mm. The corresponding moisture content is recorded as the plastic limit (PL). This value, when used alongside the liquid limit (LL), allows calculation of the Plasticity Index (PI) — a crucial measure for soil classification and foundation design.
At Amtest UK, our laboratory performs Plastic Limit testing in full compliance with BS EN ISO 17892-12:2018+A2:2022, providing reliable data for site investigation, earthworks design, and ground condition assessment. Accurate determination of soil plasticity helps ensure safe, cost-effective construction and long-term ground stability.