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.
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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.