Sampling and Laboratory Testing of Soil-cement from Soil Mixing and Slurry Trenching-Video

Video Transcription

Video Summary

Nathan Kochenauer of GeoSolutions discussed field and laboratory testing of soil-cement mixtures used in soil mixing and slurry trenching. Construction-stage checks—including viscosity, density, filter loss, and sand content—can flag issues early, though their relevance depends on the application. For soil-cement mixtures, key tests include fines content, slump, wet-grab sampling, unconfined compressive strength, and hydraulic conductivity. He emphasized that some methods are adapted from other materials and that specifications should reflect project needs.<br /><br />Kochenauer also highlighted the importance of clear significant figures and accounting for substantial sample variability when setting strength targets. Treating a 50-psi requirement as a strict minimum may require much higher average field strengths, increasing costs; clarifying whether the target is a minimum or average can help.<br /><br />During discussion, an attendee noted that filter-loss testing of cement-bentonite mixtures can help contractors estimate material loss and resulting costs, even if it is not a client compliance measure.

Keywords

soil-cement mixtures

field testing

laboratory testing

hydraulic conductivity

filter loss