Development of non-invasive measurement techniques to ascertain the shrinkage limit of silty clay through contactless ultrasonic system

초록

The shrinkage limit (SL) is a measure of the critical moisture content in fine-grained soils, marking their transition from a liquid to a solid state. The conventional techniques for determining soil moisture content, which involved the use of mercury or wax, have been phased out due to associated health risks and inefficiencies. This study introduces a novel approach for measuring SL using a contactless ultrasonic system, which leverages leaky Rayleigh waves to non-invasively assess the solid state of materials. The proposed methods have been effectively utilized to characterize the solid state of fresh concrete, like the concept of shrinkage limit in soils. Experimental investigations using silty clay were conducted to assess the proposed method, and its outcomes were compared with those derived from LiDAR and peak bulk density method. The results demonstrated a great potential of field applications, capitalizing on the automation and contactless capabilities of the proposed method.

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